MRNA vaccines make best booster shots - study

The "COV-Boost" study was cited by British officials when they announced that Pfizer and Moderna were preferred for use in the country's booster campaign, but the data has only been made publicly available now.

The study found that six of the seven boosters examined enhanced immunity after initial vaccination with Pfizer-BioNTech's vaccine, while all seven increased immunity when given after two doses of AstraZeneca's vaccine.

The study, published late on Thursday (December 2), found that a full dose or half dose of Pfizer or a full dose of Moderna gave a strong boost to both antibody and T-cell levels, regardless of whether the person initially received Pfizer or AstraZeneca.

The COV-Boost study pre-dated the spread of the emergent Omicron variant of concern, and Faust said he had shared samples with the UK Health Security Agency to generate data on Omicron.