In Phase 3 studies, both the Pfizer-BioNTech and Moderna vaccines were found to be 95% effective in the early months after the vaccine. Put simply, “If there were 100 people who would have gotten COVID, it prevented 95 of them from getting it, but it didn’t prevent all 100,” says Dr. Marks. “It definitely provides some protection, but it’s not perfect.”
The good news is that early data found that those who did contract COVID-19 after receiving the vaccine did not develop a severe form of the disease. “So even if it doesn’t completely prevent illness, the study data shows that it does reduce the severity,” says Dr. Marks.