Thursday was the most important day in the development of a potential COVID-19 vaccine.

Thursday, the advisory committee to the Food and Drug administration (FDA) that provides oversight to the development of vaccines met for the first time to consider Covid-19 vaccines. Known as the Vaccines and Related Biological Products Advisory Committee, or VRBPAC, this committee was not reviewing any specific COVID-19 vaccine, but more importantly was developing the general rules and criteria that these vaccines should meet to be judged safe and effective.

This committee is entirely unique because it involves independent experts in vaccine science and public health. Most of these individuals have spent their entire lives in the development, evaluation, and regulation of vaccines. This committee is highly vetted, and no one with any conflict of interest is allowed on the committee. There is usually a representative from the pharmaceutical and vaccine industry, but that individual is not a formal member of the committee and has no vote. In addition, this individual cannot come from a company that would be involved in any way in developing a COVID-19 vaccine.  

The criteria this committee sets will be crucial in deciding whether or not any of the vaccines currently under development are worth approval. Most of the final, Phase III clinical trials for COVID-19 vaccines involve 30,000 individuals, substantially smaller than standard vaccine trials by as much as 2/3. In addition, most of the trials are set up simply to show that fewer people will become infected with COVID-19 after the vaccine has been administered and are being compared to a control group of individuals who have not received any vaccine. 

This process leaves a number of questions unanswered. In terms of vaccine efficacy, one would want to know whether people who receive the vaccine are still able to transmit Corona virus infection to others. This would be crucial to ending the pandemic. In addition, it is clear that certain risk groups such as the elderly and people with certain preexisting conditions are more prone to infection and complications from COVID-19, and efficacy in protecting these individuals is crucial.

Safety is an issue of great concern given the smaller clinical trials. Rare side effects such as have now been observed with the AstraZeneca vaccine often are only identified in larger trials that are held over longer periods of time. This may be the biggest issue with the accelerated timeline for these vaccines. It also may mean that vaccines granted emergency use will be limited in their availability until more complete safety data is available.

Arnold Monto, a professor of epidemiology at the University of Michigan, was the temporary chairman of VRBPAC and chaired a spirited meeting. Members of the committee were very aggressive in their questioning of the FDA. They clearly want to understand why only a 50% protection rate was chosen as the efficacy endpoint and how safety will be assessed given the short timeframe of these clinical trials. The one consensus that appeared to occur among the committee is that while emergency approval might be given for these vaccines soon, their clinical trials must be continued long term to assure that better efficacy and toxicity data are generated. 

Another aspect of these advisory committees for the FDA is that they involve comments from the public. This allows advocacy organizations and individuals with issues about vaccines or clinical trials to voice their concerns. Many individuals spoke during the meeting (which was broadcast on YouTube). Concerns were raised that minority and other populations would be adequately addressed and involved in the clinical trials. Repeatedly, comments were made insisting on transparency of the review process. 

It may be that the FDA, which relies on VRBPAC for advice (but is not bound by their decision), plans to use the committee as a shield to ensure an independent evaluation of COVID-19 vaccines takes place before approval. One thing that is clear from the first meeting is that this committee is acting in a standard fashion comparable to any FDA review process despite the urgency of the Corona virus pandemic. In addition, the members of the committee generally appear beyond reproach and totally independent in their perspectives on this vaccine.

Most importantly, it may be that the simple occurrence of this meeting is a reassuring sign that any decisions on these vaccines will be based on data that show whether these vaccines are safe and effective.

Published by jbakerjrblog

Immunologist, former Army MD, former head of allergy and clinical immunology at University of Michigan, vaccine developer and opinionated guy.

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