Pfizer Reports Over 90% Efficacy for Experimental COVID-19 Vaccine
Pfizer announces that its experimental COVID-19 vaccine demonstrates more than 90% effectiveness in preventing infection based on early trial data.
Pfizer reveals that its experimental COVID-19 vaccine shows an efficacy rate of more than 90% in preventing the virus among participants who have no evidence of prior infection. This early analysis evaluates the first 94 confirmed cases of COVID-19 among the trial's over 43,000 volunteers, showing a stark difference in infection rates between those who receive the actual vaccine and those who get a placebo.
The results surpass the expectations of public health experts, who previously hope for a vaccine that achieves at least 60% to 70% effectiveness. To reach this milestone, researchers wait until at least 94 people in the study test positive for the coronavirus to determine how many of those individuals receive the dummy shot instead of the real vaccine.
Despite this promising breakthrough, the study continues to gather additional safety and efficacy data before seeking emergency use authorization from the Food and Drug Administration. Pfizer cautions that the vaccine requires two doses taken three weeks apart and faces complex logistical challenges due to its need for ultra-cold storage at minus 94 degrees Fahrenheit.