Both the Pfizer/BioNTech and the Moderna COVID-19 vaccines may be less effective against the B1351 variant first identified in South Africa, although the latter vaccine could offer good protection against the B117 variant first seen in the United Kingdom, according to two letters published yesterday in the New England Journal of Medicine.Unclear effect on effectiveness outside of labIn the letter on the Pfizer/BioNTech BNT162b2 coronavirus vaccine, a team led by scientists from the University of Texas Medical Branch in Galveston made three recombinant viruses with different mutations using a SARS-CoV-2 isolate from January 2020.