LONDON—GSK PLC and Sanofi SA reported promising trial results for their Covid-19 vaccine that showed the shot—developed to target the Beta strain of the virus—was particularly effective against the Omicron variant.
The two companies said Friday that in a trial involving 13,000 adults, the vaccine demonstrated efficacy of 64.7% against symptomatic Covid-19, and 72% efficacy in Omicron-confirmed cases. In people who already had antibodies from prior infection, the shot was 75.1% effective against symptomatic infection, rising to 93.2% in Omicron-confirmed cases. The study also found the vaccine was safe for its participants.