A single-center study today in JAMA Network Open finds longer-lasting humoral and cellular immune responses in US adults given a Johnson & Johnson (J&J) COVID-19 vaccine booster rather than a Pfizer/BioNTech booster after receiving two doses of the Pfizer vaccine at least 6 months earlier.Researchers from Beth Israel Deaconess Medical Center led the study of 68 adults in Boston given either a Pfizer or a J&J COVID-19 booster 6 or more months after receiving two doses of the Pfizer vaccine.
Enrollment took place from Aug 12 to Oct 25, 2021, and follow-up lasted 4 months.The median age of the 41 recipients of a J&J booster was 36 years, while it was 35 in the 27 Pfizer recipients.
Of all participants, 82% were women, 78% were White, 10% were Asian, 6% were Black, 6% were Hispanic or Latino, and 4% were more than one race.Antibodies fell dramatically 4 months after Pfizer boosterBoth boosters were tied to improved humoral and cellular immune responses, including against SARS-CoV-2 variants of concern such as Omicron.
A Pfizer booster was tied to a rapid rise in Omicron-neutralizing antibodies that peaked at a median titer of 1,018 in week 2, and then dropped 6.9-fold to 148 at 4 months.