The U.S. government, as well as pharmaceutical companies that manufacture COVID-19 vaccines, have promoted booster shots as a way to ramp up protection when inoculation from the initial round of vaccines begins to decrease. A new study has found that protection from a second booster dose of Pfizer’s offering begins to wane after about four weeks, though its effectiveness against severe illness lasts longer.
Second booster offers short-term COVID-19 protection, study finds
