News

COVID vaccination from Moderna is effective against developing variants like Delta

Jul, 2021

The Moderna COVID-19 Vaccine is a COVID-19 mRNA vaccine that encodes a prefusion stabilised version of the Spike (S) protein.

Several SARS-CoV-2 variants of interest (VOIs) and variants of concern (VOCs) have emerged since the COVID-19 outbreak began in late December 2019. Mutations in these lineages confer enhanced transmissibility and partial immunity to infection or vaccine-induced immunity.

The neutralising activity of Moderna's mRNA-1273 vaccine against different types of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) – the agent that causes coronavirus sickness in 2019 – has been investigated by researchers in the United States (COVID-19). The neutralising activity of sera from people who received the mRNA-1273 vaccination against emerging variants and the wild-type SARS-CoV-2 virus has now been compared (designated D614G). As a result, the research reports that neutralising antibody titers evoked by the vaccine against the B.1.1.7 (Alpha) variation of concern were comparable to those elicited by D614G. All variations, however, were sensitive to serum neutralisation induced by mRNA-1273.

Importantly, the B.1.617.2 lineage has been linked to a higher transmission rate, lower monoclonal antibody therapy efficacy, and lower susceptibility to neutralising antibodies.

Thus the researchers examined sera from eight phase 1 clinical trial participants who had received 100g of the mRNA-1273 vaccination as part of a prime-boost regimen. The ability to neutralise multiple SARS-CoV-2 variations, including VOCs and VOIs, was compared to the ability to neutralise the wild-type virus called D614G.

When compared to titers against D614G, the variation had only a minor influence on neutralising antibody titers, which were reduced by only 1.2-fold. When compared to titers against D614G, neutralisation titers for all other variants, including B.1.351 (Beta), B.1.617.2 (Delta), and P.1 (Delta), reduced by a factor of 2.1 to 8.4. Neutralization titers were reduced by 6.9 to 8.4 times across three versions of the B.1.351 mutant.

SARS-CoV-2 Pseudo virus Neutralization in Serum Samples On day 36 of the mRNA-1273 vaccination phase 1 study, serum samples were taken from participants 7 days post dose 2. The neutralisation was measured using a recombinant vesicular stomatitis virus–based pseudo virus neutralisation test.