Pfizer Is Studying the Effects of a Third COVID-19 Vaccine Dose.<br />Two doses of Pfizer's COVID-19 vaccine <br />have proven to be 95% effective at <br />preventing severe coronavirus infection.<br />On Feb. 25, the drugmaker announced it will be studying the effects of a third "booster" shot among those who were fully vaccinated over six months ago.<br />We believe that the third dose will raise the antibody response 10- to 20- fold, Pfizer CEO Albert Bourla, via NBC News.<br />Two age groups will be observed <br />in the study: 18 to 55 and 65 to 85.<br />The participants are among some of the first to have ever received Pfizer's vaccine in its initial clinical trials.<br />The third dose will be the same <br />as what they received a year ago.<br />Pfizer also intends to modify its vaccine to test against the variant from South Africa.<br />Pfizer CEO Albert Bourla suspects that much like the flu, "you will have to go and get your annual shot for COVID to be protected."
