immunity

Kids seem to be catching everything and getting sicker as the pandemic enters its third winter, leaving physicians and researchers to figure out what's going on.

Infection-fighting B cells appear to have a poorer "memory" of the COVID virus in those who've suffered severe COVID-19.

Recent studies have raised fears that immunity to the coronavirus might be fleeting, thus making potential vaccines ineffective. The reality of the science is more complex — and more reassuring.

In 2011, Bonds was found guilty of obstruction of justice but a federal appeals court has just thrown out that conviction.