Through July 2022, 19.9 million people ages 50 and up received a second booster. This represents about 30% of the 50 or older population in the US. About 1.3 million adults younger than 50 years old also received a second booster.
Immunocompromised adults and those 50 years or older can get their second booster shot starting four months after receiving the first booster, according to CDC guidelines. Only the Moderna and Pfizer-BioNTech vaccines are recommended for the second booster.
As of May 2022, CDC also recommends a second booster shot for all adults who received both a primary dose and a booster dose of the J&J/Janssen vaccine at least 4 months ago.
For children who are immunocompromised, booster eligibility differs by age. Children younger than 12 are not eligible for the second booster even if they are immunocompromised. Children ages 12 through 17 can get a second booster of the Pfizer-BioNTech vaccine after four months have passed since the first booster.
About 1 million more Pfizer vaccines have been administered for a second booster than Moderna.