The Centers for Disease Control and Prevention (CDC) has updated its COVID-19 booster shot recommendations for certain at-risk populations. Data has shown that the protection provided by the COVID-19 vaccine may decrease over time and be less effective against the Delta variant. Recent studies have also suggested that although the vaccine is successful in preventing severe disease in people aged 65 or older, it does not necessarily guard older people against symptomless infection.
In a clinical trial, the Pfizer-BioNTech booster shot, given to people who had had their second primary dose of the vaccine six months earlier, increased immune response to the virus responsible for COVID-19. According to the CDC, this heightened response should provide further protection against COVID-19, including the Delta variant.
In August 2021, the CDC made its initial booster shot recommendations, suggesting that immunocompromised people who had received two doses of the Moderna or Pfizer-BioNTech vaccine be given a third dose after four or more weeks had passed since their second.
Immunocompromised people who had received the newer Johnson & Johnson or Janssen vaccine were not recommended a third dose, due to a lack of data stemming from the vaccines’ age. In late September, these recommendations were updated so that other at-risk populations were now included among those eligible for an additional vaccine, though only if their initial doses were Pfizer-BioNTech.
For other at-risk groups who got their second dose of Pfizer-BioNTech at least six months ago, an additional, booster dose is now recommended as well. These groups are:
- People 65 years or older who live in a long term care facility
- People 50 years or older who have an underlying health condition
Additionally, some at-risk groups may receive a third dose of Pfizer-BioNTech, though the CDC does not specifically recommend they do. These are:
- People 18-49 years with an underlying health condition
- People 18 years or older at increased risk of exposure to the virus that causes COVID-19 because of occupational or living setting
These recommendations follow CDC and Food and Drug Administration (FDA) reviewal of Pfizer-BioNTech studies on the potential value of a booster shot and of data from Israel, as the country has been allowing some people to get an additional dose since July 30.
Despite booster shot recommendations, all COVID-19 vaccines are still effective at preventing severe illness, hospitalization, and death in those with their protection. Authorized vaccines were shown to mitigate the effects of COVID-19 in clinical trials, and studies have since shown that are effective in everyday circumstances as well.