Moderna said Monday it's accelerating work on a Covid-19 booster shot to guard against the recently discovered variant in South Africa.
Its researchers said its current coronavirus vaccine appears to work against the two highly transmissible strains found in the U.K. and South Africa, although it looks like it may be less effective against the latter.
The two-dose vaccine produced an antibody response against multiple variants, including B.1.1.7 and B.1.351, which were first identified in the U.K. and South Africa, respectively, according to a Moderna study conducted in collaboration with the National Institute of Allergy and Infectious Diseases. The study has not yet been peer reviewed.
The vaccine generated a weaker immune response against the South African strain, but the antibodies remained above levels that are expected to be protective against the virus, the company said, adding the findings may suggest "a potential risk of earlier waning of immunity to the new B.1.351 strains."
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"Out of an abundance of caution and leveraging the flexibility of our mRNA platform, we are advancing an emerging variant booster candidate against the variant first identified in the Republic of South Africa into the clinic to determine if it will be more effective to boost titers against this and potentially future variants," Moderna CEO Stephane Bancel said in a statement.
On Thursday, White House health advisor Dr. Anthony Fauci said new data showed that the Covid-19 vaccines currently on the market may not be as effective in guarding against new, more contagious strains of the coronavirus. Some early findings that were published in the preprint server bioRxiv indicate that the South Africa variant can evade the antibodies provided by some coronavirus treatments.
The Food and Drug Administration authorized Moderna's vaccine for people who are 18 years old and older in December.
Moderna's vaccine, like Pfizer's, uses messenger RNA, or mRNA, technology. It's a new approach to vaccines that uses genetic material to provoke an immune response. Late-stage clinical trial data published in November shows Moderna's vaccine is more than 94% effective in preventing Covid, is safe and appears to fend off severe disease. To achieve maximum effectiveness, the vaccine requires two doses taken four weeks apart.
This is a developing story. Please check back for updates.
–CNBC's Noah Higgins-Dunn contributed to this report.