By Julie Steenhuysen
CHICAGO (Reuters) – Novavax Inc said on Thursday its coronavirus vaccine was 89.3% effective in preventing COVID-19 in a trial conducted in the United Kingdom, and was nearly as effective in protecting against the more highly contagious variant first discovered in the UK, according to a preliminary analysis.
Novavax said the 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.
The company also said its vaccine was 60% effective in preventing COVID-19 among subjects who were HIV negative in its 4,400-person midstage trial in South Africa, where a concerning highly transmissible coronavirus variant first identified there has been circulating.
That variant has been shown to evade antibody protection in lab studies by Moderna Inc and Pfizer Inc and partner BioNTech SE.
“The 60% reduced risk against COVID-19 illness in vaccinated individuals in South Africans underscores the value of this vaccine to prevent illness from the highly worrisome variant currently circulating in South Africa, and which is spreading globally,” Professor Shabir Maddi, lead investigator of the Novavax vaccine trial in South Africa.
Novavax shares, which initially fell in after hours trading, turned around and were up more than 22%.
Novavax said it started making new versions of its vaccine to protect against emerging virus variants in early January and expects to select ideal candidates for a booster in the coming days. The company said it plans to initiate clinical testing of these new vaccines in the second quarter of this year.
(Reporting by Caroline Humer and Julie Steenhuysen; Editing by Bill Berkrot)