Novavax vaccine against Beta (B.1.351) variant virus showed a high immunogenic response in mice and produced neutralising antibodies
Ultrastructural morphology of the 2019 Novel Coronavirus (Covid-19). (Credit: Ecklacell/Wikipedia.)
Novavax has announced positive preclinical and clinical data and for a new vaccine directed against the SARS-CoV-2 Beta (B.1.351) variant, studied along with NVX-CoV2373.
NVX-CoV2373 is a protein-based vaccine candidate developed using the company’s recombinant nanoparticle technology and is adjuvanted with its patented saponin-based Matrix-M to enhance the immune response against the SARS-CoV-2 strain.
In the three clinical trials, the company evaluated the Beta (B.1.351)-directed vaccine as standalone, in combination, and as heterologous prime boost vaccine, compared to NVX-CoV2373.
According to the study data, the vaccines showed strong immunogenicity and protection against both the Alpha (B.1.1.7) variant, originally identified in the UK, and the Beta (B.1.351) variant originally identified in South Africa, in animals and humans.
Novavax research and development president Gregory Glenn said: “These data suggest that not only could one booster dose of this variant-directed vaccine potentially provide a robust, protective immune boost after vaccination against the original SARS-CoV-2 virus, but also the potential to provide broad protection against various virus strains if used as a primary vaccine regimen.
“This broad immune coverage is vital to controlling the pandemic as variants of concern continue to emerge worldwide that could jeopardize the protection created through ongoing COVID-19 vaccination efforts.”
The first clinical trial evaluated the immunogenicity and protection of NVX-CoV2373 and rS-B.1.351 as standalone, in combination, and as heterologous prime boost in mice.
Both the vaccines, either as standalone, in combination, or as a heterologous prime boost, offered protection in mice with Alpha (B.1.1.7) and Beta (B.1.351) variant strains of SARS-CoV-2.
In a second study, a cohort of baboons immunised with NVX-CoV2373 were one year later boosted with one or two doses of rS-B.1.351.
Seven days after the first rS-B.1.351 boost, the baboons showed a strong immune response and a strong neutralising response to Alpha (B.1.1.7) and Beta (B.1.351) strains.
NVX-CoV2373 is currently being studied in several clinical trials, including at sites where Alpha (B.1.1.7) and Beta (B.1.351) variant strains are prevalent.
The third study evaluated thirty randomly selected humans from the Phase 2 clinical trial, who received the second dose of NVX-CoV2373 vaccine.
Serum samples from the study participants were analysed for their capability to neutralise Alpha (B.1.1.7) and Beta (B.1.351) strains.
In the analysis, the serum showed a similar neutralising capacity for Alpha (B.1.1.7) strain and NVX-CoV2373, with reduced neutralising capacity against the Beta (B.1.351) strain.
The data supports the development of a Beta (B.1.351) targeted vaccine, and a booster vaccine containing a variant strain for increased antibody levels, concluded the company.