The omicron variant of SARS-Cov-2 “seems to be able” to evade antibodies produced by other variants, while in the vaccinated state it is still much higher than innate immunity generated by a virus, although its neutralization capacity is also reduced. virus. previous infection.

The current wave of covid-19 highlights a “particularly” high risk of re-infection with omicron. Therefore, a Swiss team analyzed the antibody neutralization capacity of 120 individuals infected with the original strain or variants such as alpha, beta, delta and omicron (subvariable BA.1).

The study showed omicron’s “extraordinary ability” to evade immunity, compared to the neutralization ability induced by other variants.

The team, from the University of Geneva (Unige) and University Hospital Geneva, said it “seems” that the omycron can evade antibodies produced by other variants.

In the case of those who are vaccinated, it is “still far superior” to innate immunity alone, although its neutralizing capacity is also reduced, according to a university statement.

This may explain why, according to the researchers, omicron was responsible for a net increase in infections despite vaccination, but not for hospitalizations.

The team took blood samples from 120 volunteers who were previously infected, unvaccinated, or vaccinated with one of the different variants, and infected (before or after receiving the needle needle), with a mean age of 28 to 52 years, with no significant comorbidities and one disease. mild to moderate covid-19.

• Covid: What is known about the omicron subvariables BA.4 and BA.5 causing an increase in cases
• China confirms first omicron BA.2.12.1 case: more contagious

The aim was to determine the capacity of antibodies produced during initial infection to neutralize different variants.

Benjamin Meyer of Unige has proven that Ómicron is “most effective in avoiding pre-existing natural immunity as well as, to a lesser extent, vaccination-induced immunity.”

Levels of antibodies to the original SARS-CoV-2 in vaccinated persons are “about 10 times higher than in people who develop immunity only after infection.”

The combination of both conditions, known as hybrid immunity, “seems to maintain higher and broader levels of reactive antibodies.”

Although ómicron can evade existing immunity and cause infection, hospitalization and death from covid-19, even in this variant it “continues to decline after vaccination.”

The team stressed that SARS-CoV-2 retains “an astonishing mutational capacity that appears to be accelerating.”

Therefore, surveillance is still necessary, especially as epidemiological curves have increased significantly since the emergence of BA.5, the latest sub-variant of omycron,” stressed Isabella Eckerle of Unige and team leader.