看这篇纽约时报9月30日的文章，说已经有24000名打完了第二针。计划出现32病例后分析，预定10月22日和外部专家讨论。

https://www.nytimes.com/2020/09/30/health/pfizer-covid-vaccine.html

...Pfizer begins looking for sick volunteers seven days after the second dose, ... And Pfizer’s plan allows an outside review panel to look at early data after just 32 volunteers have become ill with Covid-19. ...

...Across all of its trial sites, Pfizer said, 24,000 volunteers have received the second dose of the vaccine, more than half of the 44,000 that are expected to enroll...

...Dr. Mark Goldberger, an infectious disease expert at the Global Antibiotic Research and Development Partnership and a former F.D.A. official, noted that the agency has scheduled a meeting of outside experts to discuss experimental coronavirus vaccines on Oct. 22. 

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