(Cambridge, MA) — Moderna, the Massachusetts biotech company that produced one of two COVID-19 vaccines being used in America, says its vaccine is effective against mutant strains found in the U.K. and South Africa. But it also says the antibody response to the South African strain is six times weaker which raises concerns about how long immunity will last for people who’ve been vaccinated. Company officials say they’ll launch a clinical trial on a booster vaccine. Meanwhile, Pfizer and BioNTech say research shows its COVID-19 vaccine is effective against both the South African and UK strains.
