The director of the Centers for Disease Control and Prevention signed off on mix-and-match COVID-19 booster shots Thursday night, meaning clinics, doctors and pharmacies can begin giving them out Friday.

A CDC advisory committee recommended Thursday afternoon that Americans be allowed to choose among the Pfizer-BioNTech, Moderna, and Johnson & Johnson vaccines as a COVID-19 booster shot. The committee said it could increase protection against the disease that is killing on average 1,093 Americans a day.

"The evidence shows that all three COVID-19 vaccines authorized in the United States are safe – as demonstrated by the over 400 million vaccine doses already given. And, they are all highly effective in reducing the risk of severe disease, hospitalization, and death," CDC Director Dr. Rochelle Walensky said in a statement. 

Walenskey also endorsed a second shot for all 15 million Americans who received the one-dose J&J vaccine, as well as a booster dose for certain groups of people who got the Moderna vaccine.