Novavax Reports Effectiveness of its COVID-19 Vaccine Against South African Variant

The COVID-19 variant, B.1.351, first reported in South Africa, has proven to be problematic for the existing authorized and investigational vaccines. All the major players who created vaccines in the Western Hemisphere have been reported to be less efficacious against B.1.351. This has been witnessed in data reported in the AstraZeneca, Pfizer-BioNTech, Moderna, and Johnson & Johnson vaccines.

Novavax, biotechnology company, with its own investigational COVID-19 vaccine, is now reporting it is 51.0% efficacious against the B.1.351 variant in HIV-negative participants in its ongoing trial in South Africa. Overall, it has a 49.4% efficacy with the variant identified in 90% of the isolates.

The findings were published in the New England Journal of Medicine.

NVX-CoV2373 is the company's recombinant protein COVID-19 vaccine.

The results come from a phase 2a-b trial that assigned HIV-negative adults aged 18-64 or medically stable HIV-positive adults in the same age range. In a 1:1 ratio, participants received either 2 doses of the NVX-CoV2373 vaccine or placebo.

Primary end points were safety and vaccine efficacy against symptomatic COVID-19 at 7 days or more after the second dose among the participants without previous infection.

In 2684 participants who were COVID-19 negative—94% were HIV negative, 6% HIV positive—“predominately mild-to-moderate COVID-19 developed in 15 participants in the vaccine group and 29 in the placebo group,” the investigators reported.

Vaccine efficacy was 60.1% in the HIV-negative group. In 41 sequenced isolates, 38 were the South African variant. Post hoc vaccine efficacy was 51% effective against B.1.351. 

The investigators noted results of the J&J and AstraZeneca vaccine trials conducted in South Africa. In the former vaccine trial, the investigators reported 52% efficacy at 14 days and 64% at 28 days after 1 dose with 95% of the cases reported due to the B.1.351 variant. “Vaccine efficacy against all-severity COVID-19 specific has not been reported, precluding a direct comparison with other vaccines,” the investigators wrote.

For the latter trial, an overall vaccine efficacy was reported at 22% and 10% against the South African variant, with B.1.351 making up 95% of the cases.

While the investigators pointed out the results are preliminary, they did explain the study met its desired result.

"The vaccine fulfilled the primary objective by showing significant vaccine efficacy of 49.4% among participants who were seronegative for SARS-CoV-2 at baseline regardless of HIV serostatus," the investigators wrote.

They also noted the difference in participants who were HIV-negative and HIV-positive.

“The NVX-CoV2373 vaccine was efficacious in preventing COVID-19, with higher vaccine efficacy observed among HIV-negative participants,” the investigators concluded.

Separately, Novavax announced earlier this week it was planning to begin a pediatric arm of their ongoing phase 3 trial dosing children and adolescent participants in its ongoing phase 3 clinical trial assessment for NVX-CoV2373, the company’s investigative COVID-19 vaccine, for the prevention of the pandemic virus.