The lab has access to a high-security facility that Pfizer needed to prove its COVID-19 vaccine was working. Now the scientists there are testing the vaccine's effectiveness against viral variants.

The variant accounts for more than 6% of all infections in the U.S. and in some Western states is responsible for more than 18% of cases.

Education was already a problem area in much of Latin America. But the coronavirus made a bad situation worse, writes journalist Alejandro Tarre.

With older adults vaccinated, doctors say a growing share of their COVID-19 patients are in their 20s, 30s, 40s and 50s, as more contagious variants circulate among people who are still unvaccinated.

With less than two-thirds the population of the U.S., Brazil logged nearly 4,200 deaths on Tuesday amid reports that hospital ICUs are being overwhelmed by the surge in coronavirus cases.

COVID-19 vaccines appear to work against the new coronavirus strains, though scientists are warily watching a variant first seen in South Africa. Vaccines may need updates to keep pace with the virus.

At least 70% of people will need to be immune from the coronavirus before COVID-19 can recede through a process known as herd immunity. Vaccines can play a role. But reaching the goal won't be easy.

"The individual is a male in his 20s with no history of travel. The Department is working with the CDC on this investigation," Florida Department of Health officials announced Thursday.

The coronavirus variant is sweeping through the United Kingdom and prompting travel restrictions in other countries. France's first confirmed case is in a citizen who recently returned from London.