Two CDC studies indicate that adults who have not received a bivalent mRNA booster vaccine have little remaining protection against COVID-19–associated hospitalization and that half of Americans aged 16 and up have hybrid immunity against the virus.

The Food and Drug Administration approves Paxlovid to treat COVID-19 in adults; a National Institutes of Health study sheds new light on long COVID-19.

A World Health Organization advisory group recommends using the XBB subvariant in future vaccines; the National Institute for Occupational Safety and Health recalls eight respirators.

An HHS fact sheet details policy changes with the end of the COVID-19 public health emergency; ASPR announces Project NextGen; CDC says the Johnson & Johnson vaccine no longer is available in the United States.