As new coronavirus variants test the protections of the available vaccines, federal health officials say there's no need for booster doses right now. "Americans who have been fully vaccinated do not need a booster shot at this time," read a joint statement sent Thursday from the CDC and the FDA. The agencies added that people who are fully vaccinated are protected from severe illness and death, including from emerging variants like the highly contagious delta variant that's now the dominant strain in the U.S. and in other countries.