U.S. Food and Drug Administration (FDA) documents posted in advance of advisory group consideration of emergency use authorization (EUA) for the Pfizer-BioNTech COVID-19 vaccine revealed promising new findings, including strong protection after the first dose and protection in groups at risk for disease complications, according to a news report from the Center for Infectious Disease Research and Policy (CIDRAP) at the University of Minnesota.
The FDA analysis is based on detailed data that were not spelled out in Pfizer's press release last month that described its initial efficacy findings. The new report appears among documents released ahead of the December 10th meeting of the FDA's Vaccines and Related Biological Products Advisory Committee, which will consider the Pfizer-BioNTech EUA submission.
In November, Pfizer said that after two doses given 3 weeks apart, the vaccine's efficacy was 95 percent. But according to the FDA analysis, strong protection of about 82 percent occurred after the first doses and was 52 percent between the two doses.
The findings released last month showed that protection was nearly as high in people over age 65, an important risk group, as in younger adults. Likewise, the FDA's analysis shows that the vaccine also seems to provide equal protection among other groups at risk for more severe disease, including Blacks, Latinos, and those who are obese.
Regarding side effects, the new information shows that among people ages 16 to 55, more than half had fatigue and headaches, and roughly one-third had chills and muscle pain. The effects were slightly less pronounced in people older than age 55. The analysis found no serious adverse events. Four patients in the vaccine group experienced Bell's palsy, a temporary weakness or paralysis of facial muscles; however, the rate was not significantly higher than the background rate for the general population.
