Worrisome New Evidence That COVID-19 Vaccines Are Less Effective Against New Coronavirus Variants

Worrisome new coronavirus variants can evade antibodies that neutralize original virus.

New research at Washington University School of Medicine in St. Louis indicates that three new, fast-spreading variants of the virus that cause COVID-19 can evade antibodies that work against the original form of the virus that sparked the pandemic. With few exceptions, whether such antibodies were produced in response to vaccination or natural infection, or were purified antibodies intended for use as drugs, the researchers found more antibody is needed to neutralize the new variants.

The findings, from laboratory-based experiments and published on March 4, 2021, in Nature Medicine, suggest that COVID-19 drugs and vaccines developed thus far may become less effective as the new variants become dominant, as experts say they inevitably will. The researchers looked at variants from South Africa, the United Kingdom, and Brazil.

“We’re concerned that people whom we’d expect to have a protective level of antibodies because they have had COVID-19 or been vaccinated against it, might not be protected against the new variants,” said senior author Michael S. Diamond, MD, PhD, the Herbert S. Gasser Professor of Medicine. “There’s wide variation in how much antibody a person produces in response to vaccination or natural infection. Some people produce very high levels, and they would still likely be protected against the new, worrisome variants. But some people, especially older and immunocompromised people, may not make such high levels of antibodies. If the level of antibody needed for protection goes up tenfold, as our data indicate it does, they may not have enough. The concern is that the people who need protection the most are the ones least likely to have it.”

The virus that causes COVID-19, known as SARS-CoV-2, uses a protein called spike to latch onto and get inside cells. People infected with SARS-CoV-2 generate the most protective antibodies against the spike protein.

Consequently, spike became the prime target for COVID-19 drug and vaccine developers. The three vaccines authorized by the Food and Drug Administration (FDA) for emergency use in the U.S. — made by Pfizer/BioNTech, Moderna and Johnson & Johnson — all target spike. And potent anti-spike antibodies were selected for development into antibody-based drugs for COVID-19.

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