美國CDC疫情中心 3/29公布打疫苗效果

在第一線工作人員，
打兩針 Pfizer 或 Moderna 預防感染(包括無症狀感染！）效果 90% 
打一針效果 80%

Interim Estimates of Vaccine Effectiveness of BNT162b2 and mRNA-1273 COVID-19 Vaccines in Preventing SARS-CoV-2 Infection Among Health Care Personnel First Responders and Other Essential and Frontline Workers — Eight U.S. Locations December 2020–March 2021 March 29 2021

https://www.cdc.gov/mmwr/volumes/70/wr/mm7013e3.htm?s_cid=mm7013e3_w

https://www.cdc.gov/mmwr/volumes/70/wr/mm7013e3.htm?s_cid=mm7013e3_w