As the outbreak of the novel coronavirus continues to gain momentum in the United States, there is intense interest in the development of a vaccine. Several US drugmakers have begun working on a vaccine, independently or with federal agencies like the National Institutes of Health.
The public is hungry for news about vaccines, and progress on their development is, at times, exaggerated.
“We were able to rapidly construct our vaccine in a matter of about three hours once we had the DNA sequence from the virus available because of the power of our DNA medicine platform,’ Dr. J. Joseph Kim, Inovio’s president and CEO, told FOX Business. ‘Our goal is to start phase one human testing in the U.S. early this summer.”
Even more bullish was a January 30 Wall Street Journal editorial: “it took scientists 20 months to develop a SARS vaccine to test on humans, but the NIH hopes to have a vaccine ready for human trials by April.”
The news out of Johnson & Johnson, reported on CNN on March 30, is somewhere between government-encouraged happy talk and pernicious disinformation:
“Pharmaceutical giant Johnson & Johnson plans to begin human clinical trials of its COVID-19 vaccine by September with a goal of the first batches being made available for emergency use authorization by early next year, according to a company announcement released Monday.
Johnson & Johnson says it has been working on a vaccine since January and is partnering on the venture with the Biomedical Advanced Research and Development Authority (BARDA), a division of the Department of Health and Human Services.”
Clearly there is deep interest and a sense of urgency in all quarters. So what’s standing in the way of the rapid deployment of a vaccine? For one, there are potential safety issues, particularly with new technologies, as are being used by COVID-19 vaccine makers. And just organizing clinical trials for the necessary large-scale testing would involve a massive effort. Furthermore, the regulators at the Food and Drug Administration (FDA) get into the act once researchers have a candidate vaccine. And that’s a significant obstacle.
Dr. Anthony Fauci, the legendary, long-time director of the National Institute of Allergy and Infectious Diseases and a senior member of the White House coronavirus task force, has put into perspective the overly optimistic predictions of a vaccine that’s available in the widely cited target of 12-18 months: “a vaccine that you make and start testing in a year is not a vaccine that’s deployable.”
Dr. Fauci knows well the vicissitudes of vaccine development, testing, and approval, including the FDA’s mistaken approval of a vaccine to prevent swine flu in the 1970s, which resulted in a debacle: of the 45 million people vaccinated against the swine flu in 1976, 450 developed a serious adverse reaction—the rare, paralytic Guillain-Barré syndrome. What made the situation even worse for regulators is that the predicted epidemic never materialized, so the vaccine wasn’t even needed.
Once burned, twice shy, the old saying goes, and regulators have a long memory, so the FDA’s regulation of vaccines is especially conservative. The bar has been very high for approval of vaccines that would be administered to large numbers of healthy people. For example, before approval, the first rotavirus vaccine (RotaTeq) was tested on 72,000 healthy infants; the first human papillomavirus vaccine (Gardasil) on more than 24,000 people; and the newest shingles vaccine (Shingrix) on about 29,000 subjects. And the agency was woefully slow, lagging behind other countries, in approving the first vaccine against meningococcal B, a life-threatening bacterial infection.
Just planning and getting clinical trials of that magnitude underway for a COVID-19 vaccine would be a major undertaking. First researchers would need to recruit medical practitioners and research institutions and obtain permission from local Institutional Review Boards, to say nothing of actually producing sufficient vaccine for the trials that meet the FDA’s Current Good Manufacturing Practices standards. Then comes the accumulation, organization, and analysis of the data, first by the sponsors of the vaccine, then by regulators.
Moreover, to demonstrate efficacy—the ability of the vaccine to actually prevent the coronavirus infection—the trials would need to be done in places where the disease occurs in relatively large numbers, in order to attain sufficient statistical power to show a difference between vaccine-treated and placebo groups.
Finally, there are potential safety issues, particularly with novel, unproven technologies—which all the COVID-19 candidate vaccines use. One potential problem was revealed in preclinical experience (that is, animal studies) with vaccine candidates against other coronaviruses: They actually worsened disease due to the induction of infection-enhancing antibodies in vaccinated animals, a phenomenon called antibody-dependent enhancement.
Moreover, those SARS vaccines were never commercialized. The outbreak faded away, as a result of international cooperation and strict, tried-and-true public health measures, such as isolation, quarantine, and contact tracing.
Overly optimistic estimates of vaccine availability are a disservice because they induce some to think that if we can just hold off the apocalypse until a year from now, all will be well and we’ll have a Hollywood happy ending.
A coronavirus vaccine in the near future? I’m not holding my breath.