Rochelle Walensky, director of the U.S. Centers for Disease Control and Prevention (CDC), speaks during a Senate Health, Education, Labor, and Pensions Committee hearing in Washington, D.C., on Thursday, Nov. 4, 2021. Al Drago | Bloomberg | Getty Images
The Centers for Disease Control and Prevention on Monday strengthened its recommendation on Covid booster shots, telling all adults that they "should" get an additional dose amid growing concern about the newly identified omicron variant. "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," CDC Director Dr. Rochelle Walensky said in a statement Monday. The CDC cleared booster doses for all adults earlier this month, saying everyone over 18 "may" get a shot if they wanted one. Only people 50 and over were told they "should" get the shots at the time. The agency is now giving its strongest recommendation for everyone 18 and older, saying they should get an additional shot six months after their initial Pfizer or Moderna series, or two months after their first Johnson & Johnson shot.
The World Health Organization, in a paper published Sunday, warned that global risk posed by omicron is "very high." The variant has more than 30 mutations on its spike protein alone, some of which are associated with higher transmission and reduced antibody protection. The WHO said these mutations could fuel future surges of infection with "severe consequences." "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," Walensky said.