Novavax has released positive results from its pivotal PREVENT-19 trial of its Covid-19 vaccine, which enrolled almost 30,000 participants at 119 sites across the US and Mexico. Due to decreasing vaccination rates and high supplies of messenger ribonucleic acid (mRNA) vaccines, this vaccine may not experience much uptake in the US. A large amount of the first available doses will likely go to other countries that have a more urgent need for vaccines.
NVX-CoV2373 can serve as an alternative to adenovirus vector-based vaccines because of its easier storage requirements and higher efficacy levels. This vaccine should also be less expensive than the mRNA options, and therefore be more accessible to lower-income countries.
The trial results show that NVX-CoV2373 was 93% effective against the predominant SARS-CoV-2 variants in the trial population in the US and Mexico. A relatively high percentage of the 77 subjects who contracted Covid-19 were sequenced in this trial. Two cases were found to be caused by variant B.1.351 (Beta) and 35 caused by variant B.1.1.7 (Alpha), while the causes of the other cases were undisclosed.
No sequenced case was determined to be associated with variant B.1.617.2 (Delta), which now accounts for 10% of cases in the US. In May, the Delta variant was only responsible for 2.7% of Covid-19 cases. This increase indicates a high probability that this variant will continue its surge, especially in areas with low vaccination rates.
The vaccine’s 93% efficacy rate against variants observed in PREVENT-19 will vary when NVX-CoV2373 is used in other parts of the world. This high efficacy rate mainly applies to the Alpha and Beta variants, as they were circulating through that trial’s population. More data will be required to determine how potent this vaccine will be against additional variants present in other countries.
Earlier this year, Novavax’s Phase IIb trial in South Africa showed 48% efficacy against the Beta variant, while a Phase III trial in the UK indicated 86% efficacy against the Alpha variant. NVX-CoV2373 does, however, lack efficacy data against the other US Centres for Disease Control and Prevention (CDC) classified variants of concern, which include the Gamma (P.1), Epsilon (B.1.427/B.1.429) and Delta variants.
NVX-CoV2373 has been determined to be safe and effective, with a 90% overall efficacy rate and a 100% rate of protection against moderate and severe infections. Novavax is also testing other versions of this vaccine in an effort to increase efficacy against all variants of concern. Protection against all variant strains of SARS-CoV-2 is a key factor to control the pandemic worldwide and finally see a decline in new cases and deaths. While the vaccine may not have much uptake in the US, this vaccine is a much-needed weapon to end the global pandemic.
Novavax plans to file for regulatory approvals in the third quarter of this year. It expects to be able to manufacture 100 million doses a month by that time. Novavax currently has deals with the Serum Institute of India and Gavi, a COVAX partner, to supply them with hundreds of millions of doses. The US pre-ordered 100 million doses of NVX-CoV2373 through Operation Warp Speed, and a large number of these doses will likely be distributed to countries with a greater need for a supply of the vaccine.