Moderna (NSDQ:MRNA) is beginning a new Phase 1 study to test the effectiveness of a new version of its COVID-19 vaccine designed to enhance protection against the B.1.351 first detected in South Africa.
The recent study will help Moderna and its partner, the National Institute of Allergy and Infectious Diseases determine whether to update the vaccine.
In February, the company announced that it had completed manufacturing of a variant-specific vaccine candidate, known as 1273.351. Moderna anticipates that the clinical trial will be fully enrolled by the end of April.
The B.1.351 variant has similar mutations to other variants of concern spotted in the U.K. and Brazil.
The study will enroll approximately 210 healthy adults in four centers across the U.S.
Moderna is also testing using booster doses of its existing vaccine to boost neutralizing immunity against B.1.351 and other variants of concern.
The company will also test a multivalent booster candidate known as mRNA-1273.211 that combines its original vaccine with the mRNA-1273.351 version.
Researchers have identified the B. 1.351 SARS-CoV-2 variant in nine U.S. states.
The B.1.351 variant can evade vaccine-induced immunity to some extent. Although vaccines from Pfizer and BioNTech, and Moderna remain largely effective at neutralizing the variant, the AstraZeneca vaccine is less so. A study published in NEJM found it 10.4% effective at protecting against mild-to-moderate COVID-19 infections linked to the B. 1.351 variant.
In in vitro experiments, Moderna found the variant led to a sixfold reduction in neutralizing antibodies that its vaccine generates against the B. 1.351 SARS-CoV-2 variant compared to earlier strains.