The Centers for Disease Control and Prevention (CDC) strengthened its recommendation about COVID-19 booster shots on Monday, saying that all adults 18 and older "should" get a third vaccine dose six months after their second shot of a Pfizer-BioNTech or Moderna vaccine, or two months after their initial Johnson & Johnson shot.

What You Need To Know

  • The CDC updated its booster recommendation to say that all adults 18 and older "should" get a booster dose of a COVID-19 vaccine dose in light of the omicron variant

  • The previous guidance said that adults 50 and older "should" get a booster, and those 18 to 49 "may" get a booster

  • As of Sunday, more than 37 million Americans have received a booster dose of a COVID-19 vaccine, according to data from the CDC

The change is slight, but consequential: The previous guidance said that adults 50 and older "should" get a booster, and those 18 to 49 "may" get a booster. Now it says all adults "should" get one.

"Today, CDC is strengthening its recommendation on booster doses for individuals who are 18 years and older," CDC Director Dr. Rochelle Walensky said in a statement. 

"The recent emergence of the Omicron variant (B.1.1.529) further emphasizes the importance of vaccination, boosters, and prevention efforts needed to protect against COVID-19," Dr. Walensky continued. "Early data from South Africa suggest increased transmissibility of the Omicron variant, and scientists in the United States and around the world are urgently examining vaccine effectiveness related to this variant."

"I strongly encourage the 47 million adults who are not yet vaccinated to get vaccinated as soon as possible and to vaccinate the children and teens in their families as well because strong immunity will likely prevent serious illness," Dr. Walensky said, before urging Americans who are feeling sick to take a COVID-19 test. "Increased testing will help us identify omicron quickly."

"And finally, to stop the spread of COVID-19 we need to follow the prevention strategies we know work," she concluded, referencing wearing masks and practicing proper social distancing.

As of Sunday, more than 37 million Americans have received a booster dose of a COVID-19 vaccine, according to data from the CDC.