These are the first adjustments to social measures since the country began a long-awaited transition to a new phase in pandemic response in early November and lifted most of the restrictions.

So-called "trigger laws" in 12 states would automatically enact an abortion ban if Roe is overturned. In nine others, bans that were blocked by courts or have long been unenforced could take effect.

There's serious concern about the effectiveness of vaccines against the omicron strain. But there's also reason to be hopeful — especially for those who've had a booster.

Officials in Colorado, Hawaii, Minnesota and New York reported their first cases of the variant on Thursday, one day after the first U.S. case was identified in California.

Parents of children under 5 have to wait a little bit longer before COVID vaccines are available. In the meantime pediatricians are still working to increase vaccinations in the 5-11 age group.

Scientists may not know for a couple weeks yet how risky the new coronavirus variant will be to public health. But getting out front now about what is known helps dispel misinformation, they say.

How did this new strain of the coronavirus evolve? Researchers are investigating various possibilities. One leading theory involves ... just one person.

Protein subunit vaccines work by injecting people with a tiny portion of a virus. In the case of the COVID-19 vaccine, that tiny portion is the spike protein that the coronavirus uses to enter cells.

More should be known about the transmissibility and severity of the new variant in "days, not necessarily weeks," a senior World Health Organization scientist says.

This is the second World AIDS Day during the coronavirus pandemic. Public health officials are calling on world leaders to do more to address the inequities at the root of both crises.