"Nature" infected with new crown Omicron acquired weak "natural immunity"

SARS-CoV-2 infection in unvaccinated people, according to a new study published today in the journal Nature, by researchers at the Gladstone Institute and the University of California, San Francisco (UCSF) Omicron variants provide little long-term immunity to other varian.

In experiments using mice and blood samples from blood donors infected with the omicron virus, the team found that the omicron variants elicited only a weak immune respon.

"In an unvaccinated population, infection with an omicron virus may be roughly equivalent to a shot," said Melanie Ott, MD, director of the Gladstone Institute of Virolo.

"This study underscores the importance of sticking with vaccinations, even if you've been infected with an omicron variant before, because you're still vulnerable to reinfection," said co-author Jennifer Doudna, .

Scientists at Gladstone University and the University of California, San Francisco have detailed the immune response to infection by different COVID-19 varian.

a weaker infection

As the omicron variant of SARS-CoV-2 spreads globally in late 2021 and early 2022, anecdotal evidence has rapidly mounted that it causes less severe symptoms than delta and other worrying varian.

"When the Omicron variant first emerged, many people wondered if it could essentially act as a vaccine, eliciting a robust and broad immune response for those who don't want to be vaccinated," said co-first author of the new stu.

Scientists confirmed that despite the milder symptoms associated with omega-clones, the variant still takes hold in cells and generates an immune respon.

To find out, the team first examined the effects of omicron in mi.

The team then characterized the immune response to omegavirus infecti.

"We demonstrate in this study that the low pathogenicity of omicron is not because the virus can't take root," said .

This leaves other reasons why omicron viruses differ from other variants in terms of symptoms and immunity, including lower replication of omicron viruses, or the type of antibodies the immune system produc.

No Cross-Variant protection

What exactly is the immune response after infection with Omicron? Over time, the researchers used blood samples from mice infected with alpha, delta, and other variants of SARS-CoV-2 to measure immune cells and antibody recognition of five different viral variants-ancestral (WA1), alpha, beta, δ, the cross-reactivi.

Blood from an uninfected animal cannot neutralize any virus, in other words, block any virus' ability to replicate itse.

However, blood from omicron-infected mice only neutralized the omicron varian.

The new study shows that infection with omicron does not protect against other variants of COVID-1 In this photo, a clear area on a purple background shows the SARS-CoV-2 virus escaping from neutralizing antibodies in a patient's blood samp.

The team confirmed these results using the blood of 10 unvaccinated omicron-infected individuals -- whose blood could not neutralize other varian.

When they tested the blood of 11 unvaccinated people infected with delta virus, the samples neutralized delta virus and, to a lesser extent, other variants, as seen in mi.

When they repeated the experiment with blood from vaccinated people, the results were different: vaccinated people who were confirmed to be infected with either the Omicron or Delta virus showed the ability to neutralize all of the tested variants, giving higher protecti.

"We can't predict exactly what will happen when it comes to other variants that may evolve in the future, but based on these results, I suspect that unvaccinated people infected with omicron will have little protection," Otter sa.

But instead, vaccinated people may be more broadly protected against future mutations, especially if they have a breakthrough infecti.

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"Our results may be useful not only for individual vaccination decisions, but also for future COVID-19 vaccine design," said study co-author Charles Chiu, MD, professor of infectious diseases at UC.

These vaccines can provide broad protection against multiple varian.

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