The debate surrounding the need for boosters has largely centered on the two messenger RNA shots from Pfizer and Moderna, each of which has been the most widely used in the U.S. and, as a result, have the most detailed real-world results supporting a potential waning effect against infection and symptomatic disease.
Both Pfizer and Moderna have also touted early results showing boosters administered several months after a two-dose course significantly elevate levels of neutralizing antibodies, which are thought — but not proven — to be a potential marker of a vaccine’s potency against the coronavirus.
