Switch to Moderna booster after Pfizer shots better against omicron in 60+

Enlarge / The Comirnaty (Pfizer/BioNTech) and Moderna COVID-19 vaccines. (credit: Getty | Marcos del Mazo)

People ages 60 and older who were initially vaccinated with two Pfizer-BioNTech COVID-19 vaccine doses were better protected from the omicron coronavirus variant after being boosted with a Moderna vaccine rather than another dose of the Pfizer-BioNTech vaccine.

Those results are according to interim data from a small but randomized, controlled clinical trial in Singapore and published this week in the journal Clinical Infectious Diseases.

The study—involving 98 healthy adults—can't determine if the Moderna booster is simply superior to a Pfizer-BioNTech booster for older adults or if a mix-and-match booster strategy is inherently better. It also focused solely on antibody levels, which may or may not translate to significant differences in infection rates and other clinical differences. It also only followed people for 28 days after a booster, so it's unclear if the Moderna booster's edge will hold up over time.