All the COVID-19 Vaccine Side Effects, Explained Rozalynn S. Frazier With the Pfizer BioNTech BNT162b2 vaccine and Moderna’s mRNA-1273 vaccine currently being administered to select groups, the buzz around the COVID-19 vaccine is palpable. Public response to the idea of a vaccine has also grown more favorable, with a national survey from PEW Research Center indicating that 60 percent of Americans would definitely or probably get a vaccine for the coronavirus, up from 51 percent in September. Yet among many people who are in line to get the vaccine, those who aren’t yet eligible, and those who are hesitant, there are questions about exactly what the side effects of those vaccines are, and how often they occur.