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Trick or treat? A fact check on a COVID-19 Vaccine before Halloween

Daniel R. Lucey, MD, MPH, FIDSA
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On August 26, U.S. Food & Drug Administration Commissioner Dr. Stephen Hahn tweeted that the FDA Vaccine Advisory Committee will be convened Oct. 22 to review COVID-19 vaccines.

On August 30 Dr. Hahn was reported in the Financial Times stating he would consider issuing an EUA -- an Emergency Use Authorization -- for a COVID-19 vaccine to be given to certain groups of persons even before the end of a Phase 3 efficacy trial.

Notably, no new unlicensed vaccine candidate has ever received an EUA from the FDA.

Thus, unlike hundreds of EUAs issued over the years for diagnostic tests and therapies, there is no new unlicensed vaccine precedent for an EUA.  (The only EUA for a vaccine was in 2005 for the anthrax vaccine that had been licensed for over 30 years).

Are any of the three COVID-19 vaccine candidates currently in Phase 3 studies in the USA likely to have completed their recently updated studies prior to October 22?

The AstraZeneca Phase 3 vaccine study began in the U.S. August 31. It requires two shots, four weeks apart, for the 30,000 volunteers. In its second week, however, the study was placed on clinical hold, with all vaccinations halted, due to a neurological adverse event in one of the volunteers (in the UK). As of September 13, the US study has not resumed. Thus, this study will not be complete before October 22.

The Pfizer/BioNTech “Phase 2/3” study in the U.S.  began July 27. It requires two doses 21 days apart. On September 12, however, the announcement was made that the study planned to expand from 30,000 to 44,000 volunteers.  Thus, a two-dose study of these planned 44,000 volunteers will not be complete before October 22. As of September 14 the first dose had been given to 29,012 of 30,000 volunteers, according to the Pfizer website.

The Moderna/NIH Phase 3 vaccine study also began July 27 in the USA. It requires two doses 28 days apart. As of Friday, September 11 the first dose had been given to 23,497 (78%) of 30,000 volunteers, according to the Moderna website. Thus, by October 22 this study will not have provided safety and efficacy data after the second dose for its 30,000 volunteers to the FDA.

If none of these large efficacy and safety studies are complete by October 22, then on what basis will the FDA, and its independent Vaccine Advisory Committee, make decisions regarding potential Emergency Use Authorization for any COVID vaccines? 

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