Diseases, Conditions, Syndromes

Pfizer says third shot of vaccine boosts COVID protection

New data show that protection from both doses of the Pfizer COVID-19 vaccine decreases slightly over time, but that a third dose significantly boosts levels of antibodies against several variants of the virus, including the ...

Vaccination

States race to use COVID-19 vaccines before they expire

Hundreds of thousands of COVID-19 vaccine doses have been saved from the trash after U.S. regulators extended their expiration date for a second time, part of a nationwide effort to salvage expiring shots to battle the nation's ...

Diseases, Conditions, Syndromes

New CDC guidelines set off rush to reimpose mask mandates

New guidance from the federal government set off a cascade of mask rules across the nation Wednesday as cities, states, schools and businesses raced to restore mandates and others pushed back against the guidelines at a time ...