Novavax has announced that its COVID-19 vaccine candidate, NVX-CoV2373, demonstrated 90.4% overall efficacy in a Phase III trial conducted across sites in the US and Mexico.
The study enrolled 29,960 participants and randomised them 2:1 to receive the jab or a placebo. Overall, 77 COVID-19 cases were observed in the study – 63 in the placebo group and 14 in the vaccine group.
According to Novavax, all cases observed in the vaccinated group were mild, with ten moderate cases and four severe cases observed in the placebo group.
As such, Novavax determined that NVX-CoV2373 is 100% effective against moderate or severe COVID-19 disease.
The company added that the efficacy endpoints were accrued from 25 January through to 30 April 2021, when the B.1.1.7 – first identified in the UK – became the dominant strain in the US.
Of the COVID-19 cases sequenced in the trial, 65% were found to be variants of concern (VoC), 17% were variants of interest (VoI) and 19% were other variants.
The vaccine efficacy of NVX-CoV2373 was found to be 93.2% against VoC/VoI, which represented 82% of all the cases in total.
The jab also demonstrated benefit in high-risk patients, including those aged over 65, those aged under 65 with certain comorbidities or having life circumstances with frequent exposure to COVID-19.
Among these populations, NVX-CoV2372 demonstrated a vaccine efficacy of 91%, with 62 COVID-19 cases in the placebo group and 13 cases in the vaccine group.
On the safety front, the jab was found to be generally well-tolerated, with a ‘low number’ of serious and severe adverse events observed in the study. The most common local symptoms were injection site pain and tenderness, although these were generally mild to moderate in severity.
The most common systemic symptoms seen in the study were fatigue, headache and muscle pain, lasting less than two days.
Novavax is planning to file the vaccine for regulatory authorisations in the third quarter of 2021, after completing the final phases of process qualification and assay validation need to meet CMC requirements.