(Reuters) - Among fully vaccinated people who never had COVID-19, getting a third dose of an mRNA vaccine from Pfizer/BioNTech or Moderna would likely increase levels of antibodies, but not antibodies that are better able to neutralize new virus variants, Rockefeller University researchers reported on bioRxiv ahead of peer review.

They note that in COVID-19 survivors, the immune system's antibodies evolve during the first year, becoming more potent and better able to resist new variants.