误导。进临试者必须先测病毒和抗体，双阴才能进。三期招募从七月下旬开始至11月中。应该使用同期病例数做对比

https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-biontech-conclude-phase-3-study-covid-19-vaccine

https://www.businesswire.com/news/home/20201118005595/en/

The Phase 3 clinical trial of BNT162b2 began on July 27 and has enrolled 43,661 participants to date, 41,135 of whom have received a second dose of the vaccine candidate as of November 13, 2020. Approximately 42% of global participants and 30% of U.S. participants have racially and ethnically diverse backgrounds, and 41% of global and 45% of U.S. participants are 56-85 years of age. A breakdown of the diversity of clinical trial participants can be found here from approximately 150 clinical trials sites in United States, Germany, Turkey, South Africa, Brazil and Argentina. The trial will continue to collect efficacy and safety data in participants for an additional two years.

 

 

另外，临试采用比较准确的病毒核酸检测，基本上排除了伪阳性。

而美国目前相当大比例的阳性来自于快速检测，其真实性有待调查。

 

还有，这个临试是全球范围招募的, 不应该只用美国病例发生率做对比。