Moderna’s vaccine against COVID-19 is also effective against the new variants of the virus identified in the United Kingdom and South Africa, according to the results of ‘in vitro’ neutralization studies of sera from people vaccinated with this vaccine. The study, which has been submitted as a preprint to bioRxiv and will undergo a peer-reviewed scientific publication, did not show a significant impact on protection against the new British strain. However, it has shown a six-fold reduction in protection with the South African variant. Despite this reduction, the levels of neutralizers against the South African variant remain above the levels expected to be protective.
Thus, Moderna “hopes” that the two-dose schedule of the vaccine will be protective against emerging strains detected to date. However, the company has announced a clinical strategy to proactively cope with the pandemic as the virus continues to evolve. First, the company will test an additional booster dose of its vaccine to study the ability to further increase neutralization titers against emerging strains. Second, the company is developing a booster variant against the South African strain. Moderna has advanced that it is already in preclinical studies and in a phase 1 study in the United States to test these two possibilities.
As we attempt to defeat the virus, we believe it is imperative to be proactive as the virus evolves. We are encouraged by these new data, which reinforces our confidence that the vaccine should be protective against these newly detected variants. Out of the abundance of caution and taking advantage of the flexibility of our mRNA platform, we are advancing an emerging variant boost candidate against the variant first identified in South Africa in the clinic to determine if it will be more effective in boosting titers against this and potentially future variants, “commented the Director. General of Moderna, Stéphane Bancel.
First detected in September in the United Kingdom, the SARS-CoV-2 variant B.1.1.7 has seventeen mutations in the viral genome, with eight mutations located in the spike protein (S). Variant B.1.351, first identified in South Africa, has ten localized mutations in protein S. Both variants have spread rapidly and are associated with increased transmission and a higher viral load after infection.