Biotechnology company Novavax has announced that its protein-based Covid-19 vaccine candidate, NVX-CoV2373, met the primary endpoint in Phase III clinical trial conducted in the UK.

In the study, which enrolled over 15,000 subjects aged between 18 and 84 years, with 27% of them aged over 65 years, the vaccine candidate demonstrated 89.3% efficacy.

The first interim analysis is based on 62 cases with 56 Covid-19 cases observed in the placebo group versus six cases observed in the NVX-CoV2373 group.

Furthermore, Novavax announced successful results from its Phase IIb study conducted in South Africa.

This trial enrolled over 4,400 participants. Data showed that the vaccine had a 60% efficacy in preventing mild, moderate and severe Covid-19 disease in 94% of the study population that was HIV-negative.

In addition, the trial achieved its primary efficacy endpoint in the overall trial population, which included HIV-positive and HIV-negative subjects, with an efficacy of 49.4%.

Novavax president and CEO Stanley Erck said: “With today’s results from our UK Phase III and South Africa Phase IIb clinical trials, we have now reported data on our Covid-19 vaccine from Phase I, II and III trials involving over 20,000 participants.

“NVX-CoV2373 is the first vaccine to demonstrate not only high clinical efficacy against COVID-19 but also significant clinical efficacy against both the rapidly emerging UK and South Africa variants.”

In a separate development, the National Institutes of Health has reported preliminary findings from Gestational Research Assessments for COVID-19 (GRAVID) study which showed pregnant women who experienced severe symptoms of Covid-19 had an increased risk of complications during and after pregnancy.

Data showed that such patients with severe symptoms were at higher risk for cesarean delivery, postpartum haemorrhage, hypertensive disorders of pregnancy and preterm birth asymptomatic Covid-19 patients.

Last November, Novavax signed a non-binding Heads of Terms document with the Australian government to supply 40 million doses of NVX-CoV2373.