BREAKING NEWS: Novavax Vaccine Effective Against South African Variant in Trials

A mid-stage trial of the vaccine in South Africa, where a potent variant of the virus is common, showed 60% effectiveness among people who did not have HIV. Novavax shares rose more than 22% in after-hours trading following the report, which comes on the day the United States reported its first cases of the South African variant.

Novavax said the UK trial, which enrolled 15,000 people aged 18 to 84, is expected to be used to apply for regulatory review in Britain, the European Union and other countries. Some 27% of people in the trial are over age 65.

The study took place as the more highly transmissible UK variant was circulating, and the preliminary analysis suggests the vaccine was 85.6% effective against this mutation, the U.S. company announced in a news release. It did not provide the study data.

A mid-stage trial of the vaccine in South Africa, where a potent variant of the virus is common, showed 60% effectiveness among people who did not have HIV. Novavax shares rose more than 22% in after-hours trading following the report, which comes on the day the United States reported its first cases of the South African variant.

Novavax said the UK trial, which enrolled 15,000 people aged 18 to 84, is expected to be used to apply for regulatory review in Britain, the European Union and other countries. Some 27% of people in the trial are over age 65.

The study took place as the more highly transmissible UK variant was circulating, and the preliminary analysis suggests the vaccine was 85.6% effective against this mutation, the U.S. company announced in a news release. It did not provide the study data.