COVID-19

The hygiene hypothesis says exposure to germs helps kids develop healthy immune systems. But many viruses didn’t circulate as widely during the pandemic. Are there downsides to missed infections?

Battered by the pandemic’s challenges and pushed to their limits, researchers responded with resilience, creativity, and long hours.

Findings suggest this group should be considered for additional vaccine dosages and other risk-reduction measures.

Combining proteins from two SARS-CoV-2 variants, bivalent booster shots protect against the currently circulating BA.5 subvariant—and may afford longer-lasting immunity.

SARS-CoV-2 viral load and number of symptoms do not correlate in young children.