Safety and Efficacy of the Pfizer/BNT162b2 mRNA Covid-19 Vaccine

The New England Journal of Medicine published a study of the Safety and Efficacy of the Vaccine today. Overall, a two-dose regimen of the vaccine provided 95% protection against Covid-19 and the safety over the 2-month study period was similar to other viral vaccines.  The safety profile found short-term, mild-to-moderate pain at the injection site, fatigue, and headache. The incidence of serious adverse events was low and was similar in the vaccine and placebo groups.


Closed Environments Facilitate Transmission of Coronavirus Disease

“The odds that a primary case transmitted COVID-19 in a closed environment was 18.7 times greater compared to an open-air environment (95% confidence interval [CI]: 6.0, 57.9).” 

“It is plausible that closed environments contribute to secondary transmission of COVID-19 and promote superspreading events. Our findings are also consistent with the declining incidence of COVID-19 cases in China, as gathering in closed environments was prohibited in the wake of the rapid spread of the disease.”

This is more evidence that the most effective interventions will focus on crowded indoor environments like bars and nightclubs, consistent with the study in last week’s policy update in Nature.


CDC Publishes Study on COVID-19 Seroprevalence in the United States as of September 2020

Last week the CDC published a study in JAMA Internal Medicine that shows that most of the U.S. population is likely still susceptible to COVID-19. The study describes CDC’s collaboration with commercial laboratories to conduct and publish results from seroprevalence surveys to estimate the percentage of people in the United States who already have COVID-19 antibodies. Statewide seroprevalence estimates ranged from less than 1% in several sites to approximately 23% in New York state.