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Douglas Lowy, John Schiller, and the Vaccine Against Cervical Cancer

The 2017 Lasker-DeBakey Prize for Clinical Research went to two virologists at the National Cancer Institute, Douglas Lowy, 75, and John Schiller, 64, for developing technologies that led to FDA-approved vaccines against human papillomavirus (HPV) strains that cause cervical carcinoma and other cancers.  Lasker awards are considered the United States’ most prestigious biomedical research awards. They often precede a Nobel Prize in Physiology or Medicine. Thus, they are referred to as “America’s Nobels.” Eighty-seven Lasker awardees have gone on to win a Nobel.

Douglas Lowy and John Schiller

Lowy and Schiller’s achievements were prompted by Harald zur Hausen’s 1983 discovery that two HPV subtypes, HPV-16 and HPV-18, together account for about 70% of all cervical cancers. Since more than 120 distinct HPV subtypes had been identified, the high degree of association of cervical carcinoma with only two of these subtypes provided compelling evidence for the viral etiology of cervical carcinoma. Later studies showed that HPV-31, HPV-33, HPV-45, HPV-52, and HPV-58 are responsible for another 20% of cervical cancers. Thus, an HPV infection can be detected in virtually all cervical carcinomas. Harald zur Hausen was awarded a share of the 2008 Nobel Prize in Physiology or Medicine for his discovery. [His story is told in Harald zur Hausen, Papillomaviruses, and Cervical Cancer, posted June 19, 2015.]

Lowy and Schiller did not begin their work on papillomaviruses with the intent to produce a vaccine. Instead, like many papillomavirus researchers at the time, they were investigating how papillomavirus oncogene products affected cell growth and replication (i.e., how they cause cancer). Toward that end, they were making use of bovine papilloma virus (BPV) in their studies, rather than HPV. BPV was easier to work with than HPV, because BPV, but not HPV, could be studied in standard cell cultures (see Aside 1).

[Aside 1: The replication cycle of HPV depends upon the differentiation states of the cells making up the layers of an intact, stratified epithelium. Details are as follow. Since the outer layer of the skin is comprised of dead cells, cutaneous HPV infection requires a break or puncture of the skin for the virus to access cells of the underlying germinal stratum of the epithelium. In the actively dividing basal cells, the viral genome replicates more frequently than the cellular genome, thus amplifying the viral genome copy number. However, because the viral genes that encode the capsid proteins are not expressed in these cells, progeny virus particles, which might induce an immune response, are not yet produced. As the basal cells differentiate and move up in the epithelium, the viral genomes replicate only once per cell cycle, on average, to maintain the viral genome copy number. Then, as the infected cells go through their final stages of differentiation in the outer layers of the epithelium, the virus life cycle switches to its productive phase. Capsid proteins are produced, and thousands of virus particles are generated from the each of the infected, terminally differentiated cells. Thus, the HPV life cycle is regulated by the differentiated state of the host cell within the stratified epithelium. Because virus production is restricted to the outermost layers of the epithelium, the virus can evade the immune system, such that the infection can persist, and be passed on for years. However, in most instances, the host appears to eventually mount a successful immune response, which clears the infection.

The development of so-called organotypic raft cultures eventually made it possible to study HPV in cell culture. But one could produce only very limited amounts of the virus in that system.]

Working with BPV, Lowy and Schiller developed protocols they would later use when they turned their attention towards an HPV vaccine. One of these protocols was for an assay to measure the titer of neutralizing antibodies against BPV. Importantly, they also discovered that they could generate “virus-like particles” (VLPs), comprised only of the major BPV coat protein (L1). The BPV L1 proteins (which were generated by a baculovirus vector in insect cells) self-assembled into VLPs that were morphologically like actual BPV particles. What’s more, using their assay to measure the titer of neutralizing serum antibodies, they found that the VLPs induced neutralizing antibodies in rabbits that were effective against the actual virus. Importantly, since the VLPs did not contain viral genes, they could not cause cancer.

Again, using their assay for measuring the titer of neutralizing antibodies against BPV, Lowy and Schiller compared the immunogenicity of BVP VLPs, to that of individual BPV proteins. The VLPs indeed are more immunogenic than individual viral proteins, since they induced higher levels of neutralizing antibodies than were induced by individual L1 proteins (see Aside 2).

[Aside 2: The activation of antibody-producing B-cells is triggered by the cross-linking of their antigen-binding B-cell receptors, which is facilitated by the multimeric VLPs, but not by individual viral proteins.]

The innovations resulting from their work with BPV would enable Lowy and Schiller to overcome the formidable challenges they faced when working to develop the HPV vaccine. One obstacle was that HPV cannot replicate in standard cell cultures. Thus, it was difficult to study HPV, and importantly, it also was difficult to propagate it. Being able to propagate substantial amounts of the virus would be necessary to produce a vaccine.

Another obstacle to an HPV vaccine was the potentially unacceptable risk of inoculating people with a virus (either attenuated or killed) that contains known oncogenes. Lowy and Schiller overcame this impediment, and the one noted above, by implementing protocols they previously developed while researching BPV. Specifically, they generated HPV VLPs that were comprised only of the HPV L1 capsid protein, and which induced an immune response that produced protective antibodies. [They used the L1 protein of HPV-16; the most carcinogenic strain of HPV.]  In addition, they developed cell lines, which contained high copy numbers of the plasmid that encoded the HPV L1 protein; a step which enabled them to scale-up production of the VLPs.

Together, these breakthroughs made a compelling case for the feasibility of an HPV vaccine. So, Lowy and Schiller prevailed upon several pharmaceutical companies to produce a vaccine in commercial amounts, and to see the vaccine through the clinical trials process. Most companies remained skeptical about the ultimate success of the vaccine. But two companies, Merck and GlaxoSmithKline (which later bought Merck), accepted the challenge. Thus, Merck developed Gardasil, while GlaxoSmithKline developed Cervarix. [The VLPs in Gardasil are produced in yeast, whereas the VLPs from Cervarix are produced in insect cells, via a recombinant baculovirus.]

Clinical trials showed that the Merck and the GlaxoSmithKline vaccines induce significant antibody titers against high-risk HPVs. The US FDA approved the respective HPV vaccines in 2006 and 2009.

The HPV vaccines have had a substantial effect on human health. Consider the following: Cervical cancer is the second most common cause of death from cancer among women worldwide. HPV infection is the cause of virtually all cases of cervical cancer. HPVs also cause 95% of anal cancers, 70% of oropharyngeal cancers (more common in men than in women), 65% of vaginal cancers, 50% of vulvar cancers, and 35% of penile cancers. Next, consider that, since Gardasil and Cervarix were introduced, HPV infection rates have dropped by 50 percent among teen-age girls in U.S., even though only a third of teens between 13 to 17 years-old have received the full course (3 shots) of the vaccine (see Aside 3).

[Aside 3: Current CDC recommendations are as follows: “All kids who are 11 or 12 years old should get two shots of HPV vaccine six to twelve months apart. Adolescents who receive their two shots less than five months apart will require a third dose of HPV vaccine…If your teen hasn’t gotten the vaccine yet, talk to their doctor or nurse about getting it for them as soon as possible. If your child is older than 14 years, three shots will need to be given over 6 months. Also, three doses are still recommended for people with certain immunocompromising conditions aged 9 through 26 years.”]

Although he HPV vaccines have significantly reduced the incidence of cervical cancer in the developed world, the rates of cervical cancer in the United States are needlessly high, in comparison to the rates in other industrialized nations. The HPV vaccines have a lower acceptance rate than other childhood vaccines in the United States, perhaps because many American parents, some of whom associate with the religious right, have reservations about vaccinating their children against a sexually transmitted disease. Other individuals, liberals as well as conservatives, may oppose vaccines in general because they distrust pharmaceutical companies, or because they resent government interference in their lives. In any case, the CDC found no evidence of any increase in sexual activity among teenage girls who received the vaccine. Nor did it report any major ill effects]. See Aside 4.

[Aside 4: Since HPVs alone account for about 5% of all human cancers worldwide, we might ask what percentage of human cancers have a viral etiology. Hepatitis C virus, a flavivirus, and hepatitis B virus, a hepadnavirus, cause hepatocellular carcinoma; Epstein-Barr virus (EBV), a herpesvirus, causes Burkitt’s lymphoma and nasopharyngeal carcinoma; human herpesvirus 8 (HHV-8), causes Kaposi’s sarcoma, the most frequent cancer seen in AIDS patients; the human T-lymphotropic retrovirus I (HTLV-I) induces adult T-cell leukemia; and Merkel cell polyomavirus (MCV) causes its eponymous cancer. Together, viruses may account for as many as 20% of all human cancers, and a similar percentage of all deaths due to cancer!

As shown by the HPV vaccine, and earlier by vaccines against hepatitis B, cancers that have a viral etiology might be prevented by vaccination. Apropos hepatitis B, in the late 1980s, Merck and GlaxoSmithKline developed the respective hepatitis B vaccines, Recombivax and Engerix. Like, the HPV vaccines, they are based on VLPs, and they have significantly reduced the incidence of HBV-associated hepatoma; once one of the most lethal cancers.

Bacterial and parasitic infections too may lead to cancer. For example, Heliobacter pylori infections may lead to stomach cancer, and Schistosoma, Opisthorchis, and Clonorchis have been linked to rectum and bladder cancers in areas of Northern Africa and Southeast Asia, where those pathogens are prevalent.]

Lowy and Schiller’s achievement stands out as a superb example of basic research translating into very considerable public health benefits. Moreover, it serves as a strong endorsement for government support of basic research. To these points, Schiller noted that companies would not likely have carried out the necessary basic research and development necessary to produce the HPV vaccine, considering the seemingly small likelihood of success, as suggested by earlier failed attempts to develop a vaccine.

At a September 6, 2017 press conference announcing the Lasker-DeBakey Clinical Medical Research Award, Lowry related that he first learned about vaccines in 1955, when he went with his mother, a physician, to a talk by Jonas Salk about his then new polio vaccine. “I learned far more about polio virus and the vaccine than was probably appropriate for a 12-year-old boy.” Many years afterwards, Lowy began his “extraordinarily effective” collaboration with Schiller, which has endured for more than 30 years.

Schiller said that a high point in his career was taking his daughter to get the vaccine he helped to create. “We first came up with the idea of the vaccine when she was born and it became available when she was 13 years old (1).”

References:

  1. A Revolutionary Vaccine, New York Times, September 6, 2017.

 

 

 

 

 

 

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Vaccine Research using Children

Children have been used in vaccine research since its very beginning, usually said to have been in 1796, when Edward Jenner inoculated 8-year-old James Phipps with cowpox, and then challenged young James with actual smallpox (1). However, earlier, in 1789, Jenner inoculated his own 10-month-old son, Edward Jr., with swinepox. Edward Jr. then came down with a pox disease, which he fortunately recovered from. His father then challenged him with smallpox.

Edward Jr. survived his exposure to smallpox. But, since Edward Sr. wanted to determine the duration of young Edward’s protection, he again challenged his son with smallpox in 1791, when the boy was two.  Edward Sr. inoculated his son yet again with smallpox when the boy was three. Fortunately, young Edward was resistant to each of the smallpox challenges his father subjected him to.

Jenner used several other young children in his experiments, including his second son, Robert, who was 11-months-old at the time. One of the children in Jenner’s experiments died from a fever; possibly caused by a microbial contaminant in an inoculum. [Microbes were not known in the late 18th century.]

We have no record of how Jenner (or his wife) felt about his use of his own children. However, there is reason to believe that Jenner felt some remorse over his use of James Phipps, who he referred to as “poor James.” Jenner looked after Phipps in later years, eventually building a cottage for him; even planting flowers in front of it himself.

By the 20th century, some of the most esteemed medical researchers were using children—in institutions for the mentally deficient—to test new drugs, vaccines, and even surgical procedures. These institutions were typically underfunded and understaffed. Several of them were cited for neglecting and abusing their residents. Moreover, their young patients were usually from poor families, or were orphans, or were abandoned. Thus, many of the children had no one to look out for their interests. In addition, research at these institutions was hidden from the public. [The goings-on at these institutions were, in general, hidden from the public, and most of the public likely preferred it that way.] Federal regulations that might have protected the children were not yet in existence, and federal approval was not even required to test vaccines and drugs.

In the early 1940s, Werner Henle, of the University of Pennsylvania, used children at Pennhurst—a Pennsylvania facility for the mentally deficient—in his research to develop an influenza vaccine. [Pennhurst was eventually  infamous for its inadequate staffing, and for neglecting and abusing its patients (2). It was closed in 1987, after two decades of federal legal actions.] Henle would inoculate his subjects with the vaccine, and then expose them to influenza, using an oxygen mask fitted to their faces.

Pennhurst, a state-funded Pennsylvania facility for the mentally deficient, was one of the most shameful examples of the neglect and mistreatment that was common at these institutions. It was the site of Werner Henle’s research in the 1940s to develop an influenza vaccine.
Pennhurst, a state-funded Pennsylvania facility for the mentally deficient, was one of the most shameful examples of the neglect and mistreatment that was common at these institutions. It was the site of Werner Henle’s research in the 1940s to develop an influenza vaccine.

Henle’s vaccine did not protect all of his subjects. Moreover, it frequently caused side effects. Additionally, Henle maintained (correctly?) that a proper test of a vaccine must include a control group (i.e., a group exposed to the virus, but not to the vaccine). Thus, he deliberately exposed unvaccinated children to influenza. Children who contracted influenza had fevers as high as 104o F, as well as typical flu-like aches and pains.

Despite Henle’s investigations at Pennhuerst, he was a highly renowned virologist, best known for his later research on Epstein Barr virus. See Aside 1.

      [Aside 1: While Henle was researching his influenza vaccine at Pennhurst, Jonas Salk concurrently worked on an influenza vaccine, using adult residents (ranging in age from 20 to 70 years) at the Ypsilanti State School in Michigan.]

Next, consider Hilary Koprowski, an early competitor of Jonas Salk and Albert Sabin in the race to develop a polio vaccine (3). By 1950, Koprowski was ready to test his live polio vaccine in people. [That was four years before Sabin would be ready to do the same with his live polio vaccine.] Koprowski had already found that his vaccine protected chimpanzees against polio virus. And, he also tested his vaccine on himself. Since neither he nor the chimpanzees suffered any ill effects, Koprowski proceeded to test his vaccine on 20 children at Letchworth Village for mentally disabled children, in Rockland County, NY.  [Like Pennhurst, Letchworth Village too was cited for inadequately caring for its residents.]  Seventeen of Koprowski’s inoculated children developed antibodies to the virus, and none developed complications.

Koprowski did not initiate his association with Letchworth. Actually, Letchworth administrators, fearing an outbreak of polio at the facility, approached Koprowski, requesting that he vaccinate the children. Koprowski gave each child “a tablespoon of infectious material” in half a glass of chocolate milk (4). Koprowski never deliberately infected the Letchworth children with virulent virus.

Koprowski reported the results of his Letchworth studies at a 1951 conference of major polio researchers, attended by both Salk and Sabin. When Koprowski announced that he actually had tested a live vaccine in children, many conferees were stunned, even horrified. Sabin shouted out: “Why did you do it? Why? Why (4)?” See Aside 2.

      [Aside 2: In the 1930s, Canadian scientist Maurice Brodie tested a killed polio vaccine in twelve children, who supposedly had been “volunteered by their parents (4).” For a short time Brodie was hailed as a hero. However, too little was known at the time for Brodie to ensure that his formaldehyde treatment had sufficiently inactivated the live polio virus. Consequently, Brodie’s vaccine actually caused polio in several of the children. After this incident, most polio researchers could not conceive of ever again testing a polio vaccine, much less a live one, in children.]

Neither Koprowski nor Letchworth Village administrators notified New York State officials about the tests. Approval from the state would seem to have been required, since Koprowski later admitted that he was certain he would have been turned down. And, it is not clear whether Koprowski or the school ever got consent from the parents to use their children. However, recall there were not yet any federal regulations that required them to do so.

Koprowski was untroubled by the uproar over his use of the Letchworth children, arguing that his experiments were necessary. Yet he later acknowledged: “if we did such a thing now we’d be put on jail…” But, he added, “If Jenner or Pasteur or Theiler (see Aside 2) or myself had to repeat and test our discoveries [today], there would be no smallpox vaccine, no rabies vaccine, no yellow fever vaccine, and no live oral polio vaccine.”  Moreover, he maintained that, secret or not, his use of the Letchworth children fit well within the boundaries of accepted scientific practice.

   [Aside 2: Nobel laureate Max Theiler developed a vaccine against yellow fever in 1937; the first successful live vaccine of any kind (5). Theiler formulated a test for the efficacy of his vaccine, which did not involve exposing humans to virulent virus. Sera from vaccinated human subjects were injected into mice, which were then challenged with the Yellow Fever virus.]

Koprowski referred to the Letchworth children as “volunteers (6).” This prompted the British journal The Lancet to write: “One of the reasons for the richness of the English language is that the meaning of some words is continually changing. Such a word is “volunteer.” We may yet read in a scientific journal that an experiment was carried out with twenty volunteer mice, and that twenty other mice volunteered as controls.” See Aside 3.

     [Aside 3: Koprowski was a relatively unknown scientist when he carried out his polio research at Letchworth. He later became a renowned virologist, having overseen the development of a rabies vaccine that is still used today, and having pioneered the use of therapeutic monoclonal antibodies. Yet, he is best remembered for developing the world’s first effective polio vaccine; several years before Salk and Sabin brought out their vaccines.

   Most readers of the blog are aware that the Salk and Sabin vaccines are credited with having made the world virtually polio-free. What then became of Koprowski’s vaccine? Although it was used on four continents, it was never licensed in the United States. A small field trial of Koprowski’s vaccine in 1956, in Belfast, showed that its attenuated virus could revert to a virulent form after inoculation into humans. Yet a 1958 test, in nearly a quarter million people in the Belgian Congo, showed that the vaccine was safe and effective. Regardless, the vaccine’s fate was sealed in 1960, when the U.S. Surgeon General rejected it on safety grounds, while approving the safer Sabin vaccine. Personalities and politics may well have played a role in that decision (3, 4).

  Interestingly, Sabin developed his vaccine from a partially attenuated polio virus stock that he received from Koprowski. It happened as follows. In the early 1950s, when Koprowski’s polio research was further along than Sabin’s, Sabin approached Koprowski with the suggestion that they might exchange virus samples. Koprowski generously sent Sabin his samples, but Sabin never reciprocated.

   Koprowski liked to say: “I introduce myself as the developer of the Sabin poliomyelitis vaccine (7).” He and Sabin had a sometimes heated adversarial relationship during the time when their vaccines were in competition. But they later became friends.]

Sabin was at last ready to test his polio vaccine in people during the winter of 1954-1955. Thirty adult prisoners, at a federal prison in Chillicothe, Ohio, were the subjects for that first test in humans. [The use of prisoners also raises ethical concerns.]

Recall Sabin’s public outcry in 1951 when Koprowski announced that he used institutionalized children to test his polio vaccine. In 1954, Sabin sought permission to do the very same himself; asserting to New York state officials: “Mentally defective children, who are under constant observation in an institution over long periods of time, offer the best opportunity for the careful and prolonged follow-up studies…”

Although Sabin had already tested his attenuated viruses in adult humans (prisoners), as well as in monkeys and chimpanzees, the National Foundation for Infantile Paralysis, which funded polio research in the pre-NIH days of the 1950s, blocked his proposal to use institutionalized children. Thus, Sabin again used adult prisoners at the federal prison in Ohio. With the concurrence of prison officials, virtually every inmate over 21 years-old “volunteered,” in exchange for $25 each, and a possible reduction in sentence. None of the prisoners in the study became ill, while all developed antibodies against polio virus.

Testing in children was still a necessary step before a polio vaccine could be administered to children on a widespread basis. But, Sabin’s vaccine could not be tested in children in the United States. Millions of American children had already received the killed Salk vaccine, and the National Foundation for Infantile Paralysis was not about to support another massive field trial of a vaccine, in children, in the United States (3).

Then, in 1959, after a succession of improbable events, 10 million children in the Soviet Union were vaccinated with Sabin’s vaccine (3). The Soviets were so pleased with the results of that massive trial that they next vaccinated all seventy-seven million Soviet citizens under 20 years-of-age with the Sabin vaccine. That figure vastly exceeded the number of individuals in the United States, who were vaccinated with the rival Salk vaccine during its field trials.

Next up, we have Nobel laureate John Enders who, in the 1950’s, oversaw the development of the first measles vaccine. Enders and co-workers carried out several trials of their attenuated measles vaccine; first in monkeys and then in themselves. Since the vaccine induced an increase in measles antibody titers, while causing no ill effects, they next tested it in severely handicapped children at the Walter E. Fernald State School near Waltham, Massachusetts.

Enders seemed somewhat more sensitive than either Henle or Koprowski to the ethics of using institutionalized children. Samuel L. Katz, the physician on Enders’ team, personally explained the trial to every Fernald parent, and no child was given the vaccine without written parental consent. [Federal guidelines requiring that step still did not exist.] Also, no child was deliberately infected with virulent measles virus.

Katz personally examined each of the inoculated Fernald children every day. None of these children produced measles virus, while all of them developed elevated levels of anti-measles antibodies. Also, the Fernald School had been experiencing severe measles outbreaks before the Enders team vaccinated any of its children. But, when the next measles outbreak struck the school, all of the vaccinated children were totally protected.

In 1963, the Enders vaccine became the first measles vaccine to be licensed in the United States. Several years later it was further attenuated by Maurice Hilleman (8) and colleagues at Merck. In 1971, it was incorporated into the Merck MMR (measles, mumps, and rubella) vaccine. See Aside 4.

    [Aside 4: Before Enders carried out his measles investigations he pioneered the growth of viruses in tissue culture. In 1949, Enders, and collaborators Thomas Weller and Frederick Robbins, showed that poliovirus could be cultivated in the laboratory. This development was crucial, allowing Salk and Sabin to grow a virtually unlimited amount of polio virus and, consequently, to develop their polio vaccines. In 1954, Enders, Weller, and Robbins were awarded the Nobel Prize for Physiology or Medicine for their polio virus work.]

It may surprise some readers that before the mid 1960s the so-called Nuremburg Code of 1947 comprised the only internationally recognized ethical guidelines for experimentation on human subjects. The Nuremburg Code was drawn up by an American military tribunal during the trial of 23 Nazi physicians and scientists for atrocities they committed while carrying out so-called “medical” experiments during World War II. [Sixteen of the 23 Nazis on trial at Nuremburg were convicted, and 7 of these were executed (see Note 1)].

The Nuremberg Code’s Directives for Human Experimentation contained strongly stated guidelines. Its tenets included the need to obtain informed consent (interpreted by some to prohibit research using children), the need to minimize the risks to human subjects, and the need to insure that any risks are offset by potential benefits to society.

But, despite the well-articulated principles of the Nuremberg Code, it had little effect on research conduct in the United States. Federal rules, with the authority to regulate research conduct, would be needed for that. So, how did our current federal oversight of research come to be?

A 1996 paper in the The New England Journal of Medicine, “Ethics and Clinical Research,” by physician Henry Beecher, brought to the fore the need for rules to protect human subjects in biomedical research (9). Beecher was roused to write the paper in part by the early 1960s experiments of Saul Krugman, an infectious disease expert at NYU. Krugman used mentally deficient children at the Willowbrook State School in Staten Island, New York, to show that hepatitis A and hepatitis B are distinct diseases (9). Also, before a hepatitis vaccine was available, Krugman inoculated the children with serum from convalescing individuals, to ask whether that serum might protect the children against hepatitis. Krugman exposed the children to live virus either by injection, or via milkshakes seeded with feces from children with hepatitis.

Krugman found that convalescent sera indeed conferred passive immunity to hepatitis. Next, he discovered that by infecting passively protected patients with live hepatitis virus he could produce active immunity. Krugman had, in fact, developed the world’s first vaccine against hepatitis B virus (HBV) (see Aside 4). [Although Krugman used mentally deficient institutionalized children in his experiments, his investigations were nonetheless funded in part by a federal agency; the Armed Forces Epidemiology Section of the U.S. Surgeon General’s Office.]

         [Aside 4: The first hepatitis B vaccine licensed for widespread use was developed at Merck, based on principles put forward by Nobel Laureate Baruch Blumberg, (10).]

Beecher was particularly troubled by two aspects of Krugman’s experiments. First, Krugman infected healthy children with live virulent virus. Beecher maintained that it is morally unacceptable to deliberately infect any individual with an infectious agent, irrespective of the potential benefits to society. [See reference 11 for an alternative view. “The ethical issue is the harm done by the infection, not the mere fact of infection itself.”]

Second, Beecher charged that the Willowbrook School’s administrators coerced parents into allowing their children to be used in Krugman’s research. The circumstances were as follows. Because of overcrowding at the school, Willowbrook administrators closed admission via the usual route. However, space was still available in a separate hepatitis research building, thereby enabling admission of additional children who might be used in the research.

Were the Willowbrook parents coerced into allowing their children to be used in the research there? Consider that the parents were poor and in desperate need of a means of providing care for their mentally impaired children. Making admission of the children contingent on allowing them to be used in the research might well be viewed as coercion. Yet even today, with federal guidelines now in place to protect human subjects, institutions such as the NIH Clinical Center admit patients who agree to participate in research programs. Is that coercion?

Beecher’s 1966 paper cited a total of 22 instances of medical research that Beecher claimed were unethical (9). Four examples involved research using children. Krugman’s work at Willowbrook was the only one of these four examples that involved vaccine research. Beecher’s other examples involved research using pregnant women, fetuses, and prisoners. But it was Beecher’s condemnation of Krugman’s hepatitis research at Willowbrook that is mainly credited with stirring debate over the ethics of using children in research.

Did Krugman deserve Beecher’s condemnation? Before Krugman began his investigations at Willowbrook, he plainly laid out his intentions in a 1958 paper in the New England Journal of Medicine (12). Importantly, Krugman listed a number of ethical considerations, which show that he did not undertake his Willowbrook investigations lightly. In fact, Krugman’s ethical considerations, together with his plans to minimize risks to the children, were not unlike the assurances one might now submit to an institutional review board (11).

Many (but not all) knowledgeable biomedical researchers claimed that Beecher misunderstood Krugman’s research and, thus, unjustly vilified him. Krugman was never officially censored for his Willowbrook investigations. Moreover, condemnation of Krugman did not prevent his election in 1972 to the presidency of the American Pediatric Society, or to his 1983 Lasker Public Service Award.

To Beecher’s credit, his 1966 paper was instrumental in raising awareness of the need to regulate research using human subjects. Beecher was especially concerned with the protection of children and, apropos that, the nature of informed consent.

In 1974, the National Research Act was signed into law, creating the National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research. The basic ethical principles identified by the Commission are summarized in its so-called Belmont Report, issued in 1978. Its tenets include minimizing harm to all patients, and the need to especially protect those with “diminished autonomy” or who are incapable of “self-determination.”  In addition, federal guidelines now require universities and other research institutions to have Institutional Review Boards to protect human subjects of biomedical research. [Reference 13 (available on line) contains a detailed history of the establishment of these policies.]  See Aside 6.

      [Aside 6: The infamous U.S. Public Health Service Tuskegee syphilis research program, conducted between 1932 and 1972, in which several hundred impoverished black men were improperly advised and never given appropriate treatment for their syphilis, also raised public awareness of the need to protect human subjects. More recently, research involving embryonic stem cells and fetuses has stoked an ongoing and heated public debate. Policies regarding this research are still not settled, with stem-cell research being legal in some states, and a crime in others. Other recent technological advances, such as DNA identification and shared databases, have been raising new concerns, such as the need to protect patient privacy. In response to these new developments, in June 2016, the US National Academies of Sciences, Engineering and Medicine released a report proposing new rules (indeed a complete overhaul of the 1978 Belmont Report) to deal with these circumstances. The Academy’s report has stirred debate in the biomedical community]

Note 1: The use of children in medical research makes many of us profoundly uneasy. We may be particularly troubled by accounts of the exploitation of institutionalized children, who comprised a uniquely defenseless part of society. Indeed, it was the very vulnerability of those children that made it possible for them to be exploited by researchers. Consequently, some readers may well be asking whether the activities of vaccine researchers Krugman, Koprowski, Sabin, Henle and others might have been comparable to that of the Nazis on trial at Nuremberg. So, I offer this cautionary interjection. While in no way condoning the vaccine researchers using institutionalized children, their work was carried out for the sole purpose of saving human lives. As Koprowski suggested above, if not for that work, we might not have vaccines against smallpox, rabies, yellow fever, and polio. Now, consider Josef Mengele, a Nazi medical officer at Auschwitz, and the most infamous of the Nazi physicians. [Mengele was discussed several times at Nuremberg, but was never actually tried. Allied forces were convinced at the time that he was dead, but he had escaped to South America.] At Auschwitz, Mengele conducted germ warfare “research” in which he would infect one twin with a disease such as typhus, and then transfuse that twin’s blood into the other twin. The first twin would be allowed to die, while the second twin would be killed so that the organs of the two children might then be compared. Mengele reputedly killed fourteen twin children in a single night via a chloroform injection to the heart. Moreover, he unnecessarily amputated limbs and he experimented on pregnant women before sending them to the Auschwitz gas chambers.

References:

  1. Edward Jenner and the Smallpox Vaccine, Posted on the blog September 16, 2014.
  2.  Pennhurst Asylum: The Shame of Pennsylvania, weirnj.com/stories/pennhurst-asylum/
  3.  Jonas Salk and Albert Sabin: One of the Great Rivalries of Medical Science, Posed on the blog March 27, 2014.
  4.  Oshinsky D, Polio: An American Story, Oxford University Press, 2005.
  5. The Struggle Against Yellow Fever: Featuring Walter Reed and Max Theiler, Posted on the blog May 13, 2014.
  6.  Koprowski H, Jervis GA, and Norton TW. Immune response in human volunteers upon oral administration of a rodent-adapted strain of poliomyelitis virus. American Journal of Hygiene, 1952, 55:108-126.
  7.  Fox M, Hilary Koprowski, Who Developed First Live-Virus Polio Vaccine Dies at 96, N.Y. Times, April 20, 2013.
  8. Maurice Hilleman: Unsung Giant of Vaccinology, Posted on the blog April 14, 2014.
  9. Beecher HK. Ethics and clinical research. The New England Journal of Medicine, 1966, 274:1354–1360.
  10.  Baruch Blumberg: The Hepatitis B Virus and Vaccine, Posted on the blog June 2, 2016.
  11.  Robinson WM, The Hepatitis Experiments at the Willowbrook State School. science.jburrougs.org/mbahe/BioEthics/Articles/WillowbrookRobinson2008.pdf
  12. Ward R, Krugman S, Giles JP, Jacobs AM, Bodansky O. Infectious hepatitis: Studies of its natural history and prevention. The New England Journal of Medicine, 1958, 258:407-416.
  13.  Ethical Conduct of Clinical Research Involving Children. http://www.ncbi.nlm.nih.gov/books/NBK25549/

 

 

Baruch Blumberg: The Hepatitis B Virus and Vaccine

Hepatitis B virus (HBV), one of mankind’s most important pathogens, infects about 2 billion people worldwide, and more than 500 million individuals are life-long carriers of the virus; with most in Asia. HBV causes acute and chronic cirrhosis, as well as hepatocellular carcinoma. In point of fact, HBV is the 10th leading cause of death in the world! The serendipitous discovery of HBV, and the development of the first HBV vaccine, happened as follows. [See Note 1 for a brief review of the remarkable HBV replication strategy].

In the early 1940’s, during World War II, British doctor, F. O. MacCallum, was the first to suggest that an infectious agent might cause hepatitis. MacCallum was assigned to produce a yellow fever vaccine for British soldiers. That was how he happened to notice that soldiers tended to come down with hepatitis a few months after receiving the yellow fever vaccine.

It was fortunate that MacCallum also knew of hepatitis cases in children who received inoculations of serum from patients convalescing from measles and mumps (a means of protection against those viruses before vaccines were available), and of hepatitis cases in blood transfusion recipients, and of cases following treatments with unsterilized reused syringes.

To explain these coincidences, MacCallum hypothesized that hepatitis might be transmitted by a factor in human blood. And, since hepatitis could be transmitted by inoculation with serum that had been filtered, MacCallum proposed that the hepatitis factor might be a virus. [In 1947 MacCallum reported that hepatitis could be spread by food and water that had been contaminated with fecal material, as well as by blood. He coined the term hepatitis A for the form of the disease spread by food and water, and hepatitis B for the form transmitted via blood.] See Aside 1.

[Aside 1: The following episode, described in MacCallum’s own words (1), occurred in England during World War II: “One day in 1942, I received a message to go to Whitehall to see one of the senior medical advisers and when I arrived I was asked ‘What is this yellow fever vaccine and how dangerous is it?’ After explaining its constitution and the possibility of a mild reaction four to five days after inoculation, I was told that the Cabinet was at that moment debating whether or not Mr. Churchill should be allowed to go to Moscow, which he wished to do in a few days’ time. The yellow fever vaccine was theoretically essential before he could fly through the Middle East, but I explained that no antibody would be produced before seven to ten days so that there would be little point in giving the vaccine. It was finally decided that the vaccine would not be used, and the administrators would take care of the situation. Several months later I received an irate call from the Director of Medical Services of the RAF, who had been inoculated with the same batch of vaccine which would have been used for Mr. Churchill, and was informed that the D. G. had spent a very mouldy Christmas with hepatitis about 66 days after his inoculation…I will leave it to you to speculate on what might possibly have been the effect on the liver of our most famous statesman and our ultimate fate if  he had received the icterogenic vaccine.”]

With the advent of cell culture in the 1950s, researchers hoped that a hepatitis agent might soon be cultivated in vitro. Nonetheless, HBV was not discovered until 1966. What’s more, the discovery did not involve growing the virus in cell culture. And, reminiscent of the case of MacCallum above, the discovery was made by a researcher, Baruch S. Blumberg, who was not even working on hepatitis. Rather, Blumberg was interested in why individuals varied in their susceptibilities to various illnesses.

Nobel Laureate Baruch Blumberg
Nobel Laureate Baruch Blumberg

Blumberg sought to answer that question by identifying possibly relevant genetic differences between population groups, which, in the pre-molecular biology era, might be revealed by differences in their blood proteins. Thus, in the early 1950s, Blumberg, then working at the NIH, began collecting a panel of blood samples from diverse populations throughout the world.

Blumberg looked for serum protein variations (i.e., serum protein polymorphisms) by asking if sera from multiply-transfused individuals (defined by Blumberg as persons who received 25 units of blood or more) might contain antibodies that reacted with proteins in the serum samples of his panel. His rational, in his own words, was as follows: “We decided to test the hypothesis that patients who received large numbers of transfusions might develop antibodies against one or more of the polymorphic serum proteins (either known or unknown) which they themselves had not inherited, but which the blood donors had (2).” In other words, patients who received multiple transfusions were more likely than others to have antibodies against polymorphic serum proteins in donor blood, and those antibodies might also react with polymorphic serum proteins in the samples from his panel. See Aside 2.

[Aside 2: Blumberg used the Ouchterlony double-diffusion agar gel technique in these experiments. Serum samples to be tested against each other were placed in opposite wells of a gel. The proteins they contained could then diffuse through the gel. Antigen-antibody complexes that formed between the two samples appeared as white lines in the gel.]

Hemophilia and leukemia patients were well-represented in Blumberg’s collection of serum samples from multiply-transfused individuals. And, a serendipitous aspect of Blumberg’s experimental approach was that he used these samples to probe for serum protein polymorphisms in samples from geographically diverse populations. Thus it happened that Blumberg detected a cross-reaction between a New York hemophilia patient’s serum and a serum sample from an Australian aborigine. But what could these two individuals have had in common that might have triggered the cross-reaction?

His curiosity thus aroused, Blumberg and collaborator, Harvey Alter, of the NIH Blood Bank, tested the hemophilia patient’s serum against thousands of other serum samples. Blumberg and Alter may have been surprised to find that whatever the antigen in the Aborigine’s serum was that reacted with the hemophilia patient’s serum, reactivity against that antigen was common (one in ten) in leukemia patients, but rare (one in 1,000) in normal individuals. In any case, because the antigen was first identified in an Australian aborigine, it was termed the Australia antigen.

Bear in mind that Blumberg’s original purpose was to explain why individuals differed in their susceptibilities to various illnesses. Thus, Blumberg at first believed that he detected an inherited blood-protein that predisposes people to leukemia. However, additional experiments showed that the antigen was more common in older individuals than in younger ones; a finding more consistent with the possibility that the antigen might be associated with an infectious agent.

Blumberg’s first clue that the Australia antigen might be associated with hepatitis came to light when he tested serum samples from a 12-year old boy with Down syndrome. The first time that the boy was tested for the Australia antigen, he was negative. However, several months later, when retested, the boy was positive. Moreover, sometime during that interim, the boy also developed hepatitis.

Blumberg, and other researchers, carried out additional experiments, which confirmed that the Australia antigen indeed associated with hepatitis. In addition, the antigen was more frequently detected in hepatitis sufferers than in individuals with other liver diseases. Thus, the Australia antigen was a marker of hepatitis in particular and not of liver pathology in general. See Aside 3.

[Aside 3: Blumberg had a personal reason motivating him to identify the cause of hepatitis. His technician (later Dr. Barbara Werner) became ill with hepatitis, which she almost certainly acquired in the laboratory. Fortunately, she underwent a complete recovery.]

In 1970, British pathologist David Dane and colleagues at Middlesex Hospital in London, and K. E. Anderson and colleagues in New York, provided corroborating evidence  that hepatitis is an infectious disease. Using electron microscopy, they observed 42-nm “virus-like particles” in the sera of patients who were positive for the Australia antigen. In addition, they saw these same particles in liver cells of patients with hepatitis.

What then is the Australia antigen? Actually, it is the surface protein of the 42-nm HBV particles; now known as the hepatitis B surface antigen (HBsAg). Since HBV particles per se were described for the first time by David Dane, they are sometimes referred to as Dane particles.

Now we can explain Blumberg’s early finding, that individuals who received multiple transfusions (e.g., leukemia and hemophilia patients) were more likely than the general population to have antibodies against the Australia antigen. Those individuals were more likely than the general population to have received donated blood and, thus, were more likely to have been recipients of blood contaminated with HBV. At that time, a large percentage of the blood supply came from paid donors, at least some of whom were syringe-sharing, intravenous drug abusers and, consequently, more likely than most to be HBV carriers. In 1972 it became law in the United States that all donated blood be screened for HBV. See Note 2.

But it was important to protect all people from HBV; not just transfusion recipients. In 1968, Blumberg, now at the Fox Chase Cancer Center in Philadelphia, and collaborator Irving Millman, hypothesized that HBsAg might provoke an immune response that would protect people against HBV and, consequently, that a vaccine could be made using HBsAg purified from the blood of HBV carriers. In Blumberg’s own words: “Irving Millman and I applied separation techniques for isolating and purifying the surface antigen and proposed using this material as a vaccine. To our knowledge, this was a unique approach to the production of a vaccine; that is, obtaining the immunizing antigen directly from the blood of human carriers of the virus (1).”  The Fox Chase Cancer Center filed a patent for the process in 1969.

Blumberg was willing to share his method and the patent with any pharmaceutical company willing to develop an HBV vaccine for widespread use. Nonetheless, the scientific establishment was somewhat slow to accept his experimental findings and his proposal for making the vaccine. Then, in 1971, Merck accepted a license from Fox Chase to develop the vaccine. In 1982, after more years of research and testing, Maurice Hillman (3) and colleagues at Merck turned out the first commercial HBV vaccine (“Heptavax”). Producing an HBV vaccine, without having to cultivate the virus in vitro, was considered one of the major medical achievements of the day. See Notes 3 and 4.

The consequences of Blumberg’s vaccine were immediate and striking. For instance, in China the rate of chronic HBV infection among children fell from 15% to around 1% in less than a decade. And, in the United States, and in many other countries, post-transfusion hepatitis B was nearly eradicated.

Moreover, Blumberg’s HBV vaccine was, in a real sense, the world’s first anti-cancer vaccine since it prevented HBV-induced hepatocellular carcinoma, which accounts for 80% of all liver cancer; the 9th leading cause of death. Jonathan Chernoff (the scientific director of the Fox Chase Cancer Center, where Blumberg spent most of his professional life) stated: “I think it’s fair to say that Barry (Blumberg) prevented more cancer deaths than any person who’s ever lived (4).”

In 1976 Blumberg was awarded the Nobel Prize in Physiology or Medicine for “discoveries concerning new mechanisms for the origin and dissemination of infectious diseases.” He shared the award with Carlton Gajdusek, who won his portion for discoveries regarding the epidemiology of kuru (5). See Note 5.

Blumberg claimed that saving lives was the whole point of his career. “This is what drew me to medicine. There is, in Jewish thought, this idea that if you save a single life, you save the whole world, and that affected me (7).” See Aside 4.

[Aside 4: Blumberg received his elementary school education at an orthodox yeshiva in Brooklyn, and he attended weekly Talmud discussion classes until his death. Interestingly, Blumberg graduated from Far Rockaway High School in Queens, N.Y.; also the alma mater of fellow Nobel laureates, physicists Burton Richter and Richard Feynman.]

As we’ve seen, Blumberg’s landmark discovery of HBV sprang from a basic study of human genetic polymorphisms. In Blumberg’s own words, “… it is clear that I could not have planned the investigation at its beginning to find the cause of hepatitis B. This experience does not encourage an approach to basic research which is based exclusively on specific-goal-directed programs for the solution of biological problems (1).”

Saul Krugman (Note 4) had this to say about Blumberg’s discovery: “It is well known that Blumberg’s study that led to the discovery of Australia antigen was not designed to discover the causative agent of type B hepatitis. If he had included this objective in his grant application, the study section would have considered him either naïve or out of his mind. Yet the chance inclusion of one serum specimen from an Australian aborigine in a panel of 24 sera that was used in his study of polymorphisms in serum proteins…led to detection of an antigen that subsequently proved to be the hepatitis B surface antigen (1).” See Note 6.

In 1999, Blumberg’s scientific career took a rather curious turn when he accepted an appointment by NASA administrator, Dan Goldin, to head the NASA Astrobiology Institute. There, Blumberg helped to establish NASA’s search for extraterrestrial life. Blumberg also served on the board of the SETI Institute in Mountain View, Calif.

Blumberg passed away on April 5, 2011, at 85 years of age.

Notes:

[Note 1:  HBV is the prototype virus for the hepadnavirus family, which displays the most remarkable, and perhaps bizarre, viral replication strategy known. In brief, in the cell nucleus, the cellular RNA polymerase II enzyme transcribes the hepadnavirus circular, double-stranded DNA genome, thereby generating several distinct species of viral RNA transcripts, all of which are exported to the cytoplasm. The largest of these viral transcripts is the pregenomic RNA; a transcript of the entire circular viral DNA genome, as well as an additional terminal redundant sequence. Remarkably, the pregenomic RNA is then packaged in nascent virus capsids, within which it is reverse transcribed by a virus-encoded reverse transcriptase activity, thereby becoming an encapsulated progeny hepadnavirus double-stranded DNA genome. Thus, reverse transcription is a crucial step in the replication cycle of the hepadnaviruses, as it is in the case of the retroviruses. But, while the retroviruses replicate their RNA genomes via a DNA intermediate, the hepadnaviruses replicate their DNA genomes via an RNA intermediate.]

[Note 2: The highly sensitive radioimmunoassay (RIA) technique, developed by Rosalyn Yallow and Solomon Berson, is the basis for the test that screens the blood supply for the Australia antigen. The story behind this assay is worthy of note here because it is yet another example of serendipity in the progress of science. In brief, Yallow and Berson sought to develop an assay to measure insulin levels in diabetics. Towards that end, they happened to find that radioactively-labeled insulin disappeared more slowly from the blood samples of people previously given an injection of insulin than from the blood samples of untreated patients. That observation led them to conclude that the treated patients had earlier generated an insulin-binding antibody. And, from that premise they hit upon the RIA procedure. Using their insulin test as an example, they would add increasing amounts of an unlabelled insulin sample to a known amount of antibody bound to radioactively labeled insulin. They would then measure the amount label displaced from the antibody, from which they could calculate the amount of unlabelled insulin in the test sample. Their procedure has since been applied to hundreds of other substances. RIA is simpler to carry out and also about 1,000-fold more sensitive than the double-diffusion agar gel procedure that Blumberg used to identify the Australia antigen. Yallow and Berson refused to patent their RIA procedure, despite its huge commercial value. Yallow received a share of the 1977 Nobel Prize in Physiology or Medicine for her role in its development. Berson, died in 1972 and did not share in the award.]

[Note 3: Making Heptavax directly from the blood of human HBV carriers was somewhat hindered because it required a continuing and uncertain supply of suitable donor blood. Moreover, there was concern that even after purifying the HBsAg, and treating it with formalin to inactivate any infectivity, the vaccine might yet contain other live dangerous viruses. Concern increased in the early 1980s with the emergence of HIV/AIDS, since much of the HBV-infected serum came from donors who later developed AIDS. Thus, in 1990 Heptavax was replaced in the United States by a safer genetically engineered (i.e., DNA recombinant) HBV vaccine, which contained no virus whatsoever. That vaccine was the first to be made using recombinant DNA technology. Moreover, it was yet another instance in which Hilleman played a key role in the development of a vaccine (3).]

[Note 4: In 1971, Saul Krugman, working at NYU, was actually the first researcher to make a “vaccine” against HBV. Krugman’s accomplishment began as a straightforward inquiry into whether heat (boiling) might kill HAV (see Note 5). Finding that it did, Krugman repeated his experiments; this time to determine whether boiling might likewise kill HBV in the serum of HBV carriers. As Krugman expected, boiling indeed destroyed HBV infectivity. But, to his surprise, while the heated serum was no longer infectious, it did induce incomplete, but statistically significant protection against challenge with live HBV. Krugman considers his “vaccine” discovery, like Blumberg’s discovery of HBV, to have resulted from “pure serendipity” (1).

Krugman could not answer whether HBsAg per se in his crude vaccine induced immunity. However, Hilleman, in 1975, using purified HBsAg, as per Blumberg’s concept, showed that HBsAg indeed induced immunity against an intravenous challenge with HBV.

Krugman also carried out key studies on the epidemiology of hepatitis, demonstrating that “infectious” (type A) hepatitis is transmitted by the fecal-oral route, while the more serious “serum” (type B) hepatitis is transmitted by blood and sexual contact.

Krugman reputation was somewhat tarnished because he used institutionalized disabled children as test subjects in the experiments that led to his vaccine. While that practice astonishes us today, it was not unheard-of in the day. In any event, it did not prevent Krugman’s election in 1972 as president of the American Pediatric Society, or his 1983 Lasker Public Service Award.]

[Note 5: Gajdusek’s reputation was later sullied when he was convicted of child molestation (5).]

[Note 6: In 1973 and 1974, research groups led by Stephen Feinstone and Maurice Hilleman (3) discovered hepatitis A virus (HAV), a picornavirus.

After the discoveries of HAV and HBV, it became clear that blood samples cleared of HAV and HBV could still transmit hepatitis. In 1983 Mikhail Balayan identified a virus, now known a hepatitis E virus (the prototype of a new family of RNA viruses), as the cause of a non-A, non-B infectious hepatitis (6).

In 1989, a mysterious non-A, non-B hepatitis agent, now known as hepatitis C virus (a flavivirus), was identified by a team of molecular biologists using the cutting-edge molecular biology techniques of the day (8).]

References:

  1. Krugman, S. 1976. Viral Hepatitis: Overview and Historical Perspectives. The Yale Journal of Biology and Medicine 49:199-203.
  1. Blumberg, B, Australia Antigen and the Biology of Hepatitis B, Nobel Lecture, December 13, 1976.
  1. Maurice Hilleman: Unsung Giant of Vaccinology, Posted on the blog April 24, 20143.
  1. Emma Brown (6 April 2011). “Nobelist Baruch Blumberg, who discovered hepatitis B, dies at 85”. The Washington Post.
  1. Carlton Gajdusek, Kuru, and Cannibalism, Posted on the blog April 6, 2015.
  1. Mikhail Balayan and the Bizarre Discovery of Hepatitis E Virus, Posted on the blog May 3, 2016.
  1. Segelken, H. Roger (6 April 2011). “Baruch Blumberg, Who Discovered and Tackled Hepatitis B, Dies at 85”. New York Times.
  1. Choo, Q. L., G. Kuo, A.J. Weiner, L.R. Overby, D.W. Bradley, and M. Houghton. 1989. Isolation of a cDNA clone derived from non-A, non-B viral hepatitis genome. Science 244:359-362.