How Omicron infection turbo-charges vaccinated people’s immunity

Bloomberg: People who are vaccinated and then get infected with Omicron may be primed to overcome a broad range of coronavirus variants, early research suggests.

A pair of studies showed that infection produced even better immune responses than a booster shot in vaccinated patients. Teams from Covid-19 vaccine maker BioNTech SE and the University of Washington posted the results on preprint server bioRxiv in recent weeks.

The findings offer a reassuring sign that the millions of vaccinated people who’ve caught omicron probably won’t become seriously ill from another variant soon — even though the research needs to be confirmed, especially by real-world evidence.

“We should think about breakthrough infections as essentially equivalent to another dose of vaccine,” said John Wherry, a professor and director of the Institute for Immunology at the University of Pennsylvania who wasn’t involved in the research but reviewed the BioNTech study. That could mean that if someone had Covid recently, they could wait before getting another booster shot, according to Wherry.

Alexandra Walls, a principal scientist at the University of Washington who authored one of the studies, cautioned that people shouldn’t seek out infections in response to the findings.

The data comes as omicron continue to fuel outbreaks around the world, most notably in China, where residents of Shanghai have endured almost six weeks of lockdown. Waves of new variants are coming more quickly in part because Omicron is so transmissible, giving it ample opportunity to spread and mutate as countries drop restrictions, said Sam Fazeli, an analyst with Bloomberg Intelligence. Meanwhile, regulators are weighing whether Covid vaccines should be updated to target Omicron.

BioNTech’s team argued that the data indicate that offering people an omicron-adapted booster shot may be more beneficial than multiple ones with the original vaccines.

The Washington research, conducted together with Vir Biotechnology Inc, looked at blood samples from people who had been infected, then had two or three doses of vaccine, as well as those who’d caught the delta and Omicron variants after two or three doses; others still had been vaccinated and boosted but never caught Covid. A final group had only been infected with omicron and never vaccinated.

One part of the study zeroed in on antibodies, the protective proteins tailored to recognize and neutralise invaders. It showed vaccinated people who’d caught omicron had antibodies that outperformed the others. They were even capable of recognizing and attacking the very different delta variant.

“That indicates that we are at the point where we may want to consider having a different vaccine to boost people,” said David Veesler, an assistant professor at the University of Washington, who led the research. The scientists were also able to identify antibodies in the nasal mucous of these patients, which could help them neutralise the virus as soon as it enters the body.