Pfizer Says Shot Remains More Than 91% Effective After 6 Months
The Pfizer Inc.-BioNTech SE vaccine remained highly effective against Covid-19 after six months, according to new long-term results that Pfizer said could be used to seek an expansion of the shot's regulatory status. data from a final-stage trial of 46,307 people showed the vaccine was 91.3% effective in preventing symptomatic cases starting one week after the second dose through as long as six months. In the U.S. alone, the efficacy rate was 92.6%, according to a report Thursday by the two companies. At the same time, the companies provided some of the first data on how their vaccine might handle the immune-evading B.1.351 variant that arose in South Africa. Nine of 800 trial participants in that country got sick with Covid, including six infected with B.1.351. However, all were in the placebo group, suggesting the shot retains efficacy against the variant.