• Posted April 8, 2021

Two Vaccines Show Effectiveness Against Emerging COVID Variants

Two COVID-19 vaccines appear to work well against a rapidly spreading coronavirus variant that arose in California, but less effective against a variant that first emerged in South Africa, researchers report.

"The good news is the California variant does not appear to be a problem for our current vaccines," said study author David Montefiori, director of the Laboratory for AIDS Vaccine Research and Development at Duke University, in Durham, N.C.

"That's important to know because this variant is now as prevalent in the U.S. as the U.K. variant, both of which appear to be more contagious," he added.

For the study, researchers tested blood samples from people who had received either the Moderna vaccine now being used in the United States or a vaccine candidate from Novovax that's expected to be considered for U.S. Food and Drug Administration (FDA) approval within weeks.

When the blood samples from people who received both doses of the Moderna vaccine were exposed to the California variant, the vaccine remained strongly protective. The Novovax vaccine also performed well against it.

The California variant has spread rapidly throughout the United States and 25 other countries.

Unfortunately, both vaccines showed significant declines in effectiveness against the South Africa variant, according to the research letter published April 7 in the New England Journal of Medicine.

While researchers didn't test the Pfizer vaccine, they said the findings would be comparable to those for the Moderna vaccine because both use similar technology.

More information

The U.S. Centers for Disease Control and Prevention has more on COVID-19 variants.

SOURCE: Duke University, news release, April 7, 2021