Despite causing a surge in infections this summer that has resulted in thousands of hospitalizations and deaths, the delta variant of the virus that causes COVID-19 is not particularly good at evading the antibodies generated by vaccination, according to a study by researchers at Washington University School of Medicine in St. Louis.

The researchers analyzed a panel of antibodies generated by people in response to the Pfizer COVID-19 vaccine and found that delta was unable to evade all but one of the antibodies they tested. Other variants of concern, such as beta, avoided recognition and neutralization by several of the antibodies.

The findings, published Aug. 16 in the journal Immunity, help explain why vaccinated people have largely escaped the worst of the delta surge.

In previous studies, co-senior author Ali Ellebedy, PhD, an associate professor of pathology & immunology, of medicine and of molecular microbiology, had shown that both natural infection and vaccination elicit lasting antibody production. But the length of the antibody response is only one aspect of protection. The breadth matters, too. An ideal antibody response includes a diverse set of antibodies with the flexibility to recognize many slightly different variants of the virus. Breadth confers resilience. Even if a few antibodies lose the ability to recognize a new variant, other antibodies in the arsenal should remain capable of neutralizing it.

Read more at Washington University School of Medicine

Image: Cherry Grimmett, a BJC HealthCare security officer, receives her first dose of the Pfizer COVID-19 vaccine in December 2020. Researchers at Washington University School of Medicine in St. Louis have found that the delta variant of the virus that causes COVID-19 is largely unable to evade antibodies elicited by vaccination. The findings help explain why vaccinated people have been at low risk of getting seriously ill with COVID-19 despite a surge in cases caused by the delta variant. (Credit: Matt Miller/Washington University) (Usage Restrictions: This image is to be used in accordance with the mission, policies and guidelines of Washington University in St. Louis. Visit https://wustl.edu/about/compliance-policies/media-policies/multimedia-use/ for more information.)