Study: Covid boosters protect against ‘severe disease’ from Omicron

Seattle (tca/dpa) — While Omicron subvariants have evolved to evade antibody responses from the primary Covid-19 vaccine series, a new laboratory study led by researchers in the US suggests boosters may offer some protection against serious disease.

An international research team analysed plasma samples from people who had been infected with Covid-19 before vaccines were available, from those who had completed only a primary vaccine series, and from others who had been boosted with currently available vaccines.

Led by the lab of David Veesler, associate professor of biochemistry at the University of Washington School of Medicine, the research team assessed seven of the world’s primary vaccines as well as immunity acquired through previous infection.

The team consisted of infectious disease research physicians and scientists from UW Medicine, Fred Hutch Cancer Center, and research institutes in California, Argentina, Italy, Pakistan and Switzerland.

The vaccines included in the study were Moderna, Pfizer, Novavax, Jannsen, AstraZeneca, Sinopharm and Sputnik V.

The Omicron variant has several sublineages, including BA.5, which is predicted to soon dominate globally and is likely to become the most immune-evasive SARS-CoV-2 variant to date, UW said in a news release about the study.

As reinfections and breakthrough cases rise, public health officials around the world are recommending boosters several months after the initial vaccine series. Veesler and his team measured and compared the benefits of vaccine boosters on the plasma-neutralizing activity against the original coronavirus as well as against the Omicron subvariants.

The study, published in July in Science, found a marked improvement in Omicron-neutralizing activity in the plasma of boosted individuals. The authors said this highlights the importance of vaccine boosters in improving antibody responses against Omicron strains, including BA.5.

“Vaccine boosters may provide sufficient protection against Omicron-induced severe disease,” the authors wrote in the study’s summary.