EU leaders will grapple Thursday with the threat of new coronavirus variants whose spread risks outpacing the hope that vaccines will put a quickish end to the pandemic in Europe.

New US President Joe Biden warned the worst of the pandemic is still to come, as the number of American coronavirus deaths surpassed the country’s troop fatalities in World War II.

California said it’s safe to immediately begin using a batch of coronavirus vaccine doses after health officials urged a halt to injections and held a review because several people fell ill.

Mexico is recording some of its highest daily death tolls since the coronavirus pandemic began, with 1,539 deaths reported Wednesday and 1,584 the previous day.

Lani Muller doesn’t have to visit a doctor’s office to help test an experimental COVID-19 vaccine—she just climbs into a bloodmobile-like van that parks on a busy street near her New York City neighborhood.