(CNN) The US Food and Drug Administration is expected to announce within the next 48 hours that it is authorizing Covid-19 vaccine booster shots for some people who are immunocompromised, according to a source familiar with the discussions. "The FDA is closely monitoring data as it becomes available from studies administering an additional dose of the authorized COVID-19 vaccines to immunocompromised individuals," an FDA spokesperson told CNN. The FDA must give authorization for the vaccines to be used in new ways outside the existing authorization. All three Covid-19 vaccines being used in the US are given under emergency use authorization by the FDA, but full approval is pending for Pfizer's vaccine. After FDA grants approval or authorization, the US Centers for Disease Control and Prevention then advises on whether to actually use a vaccine as authorized by the FDA.

Source: CNN August 11, 2021 21:06 UTC