Experts don't know yet because they're still studying vaccinated people to see when protection might wear off. How well the vaccines work against emerging variants will also determine if, when and how often additional shots might be needed.
SAN FRANCISCO (AP) — California public schools have experienced a sharp decline in enrollment this year as the pandemic forced millions into online school, according to data made public Thursday.
One of the largest reports on COVID-19 vaccination in pregnancy bolsters evidence that it is safe although the authors say more comprehensive research is needed.
A limited number of spectators will be allowed at the U.S. Women's Open in San Francisco and the U.S. Open in San Diego in June provided they are vaccinated or can show proof of a negative test for the coronavirus.