According to the first results released on Wednesday by Moderna Inc., a biotechnology company, the modern SARS-CoV-2 vaccine booster is specifically developed with the variant B.1.351 demonstrates efficacy against that strain and the P1 variant in those already vaccinated for COVID-19.
In addition, the company’s ongoing Phase 2 study demonstrates that variant-specific boosters, known as mRNA-1273.351, have higher antibody titers than the B.1.351 variants compared to boosters with the original modern vaccine.
Stephane Bancel, chief executive officer of Moderna, said in a statement, “We are encouraged by these new data, which reinforce our confidence that our booster strategy should be protective against these newly detected variants. The strong and rapid boost in titers to levels above primary vaccination also clearly demonstrates the ability of mRNA-1273 to induce immune memory”.
Researchers from the Phase 2 study are evaluating a multivariate booster that is a 50/50 mixture of mRNA-1273.351 and mRNA-1273, the initial vaccine given to the FDA Emergency Use Authority in the single vial. Unlike the two-dose diet with the original vaccine, boosters are administered as a single-dose vaccination.
Trial participants received a booster 6 to 8 months after primary vaccination. Titers of wild-type SARS-CoV-2 virus remained high and detectable in 37 of the 40 participants. However, prior to the boosters, titers were lower against the two variants of anxiety, B.1.351 and P.1, with nearly half of the participants showing undesirable levels.
In contrast, 2 weeks after receiving the booster with the original vaccine or the B.1.351 strain-specific product, pseudovirus was neutralized titers in all participants and all variants tested.
“Following boost, geometric mean titers against wild type, B.1.351, and P.1 variants increased to levels similar to or higher than previously reported peak titers compared to parental (D614G) strains after primary vaccination,” the company said.
The company plans to shortly release data on booster efficacy at additional time points in addition to data on low dose boosters with mRNA-1272/351, beyond two weeks from mRNA-1273.351, as well as data on their various mRNA vaccine boosters.
In addition to the company’s Phase 2 study, the National Institute of Allergy and Infectious Diseases is undertaking a separate Phase 1 study of mRNA-1273.351.