The Omicron variant of the coronavirus can largely escape the immune protection offered by either vaccines, previous disease or monoclonal antibodies, confirm five new studies published in the journal Nature. Laboratory (non-clinical) studies, some of which have been pre-published, show that those who have previously been ill with Covid-19 and those who have been fully vaccinated – even those who have received a third dose – are at risk of being infected with Omicron. At the same time, the new variant appears to be completely or largely resistant to all monoclonal antibodies used clinically today.
The most important of the five studies, led by David Ho, a professor of medicine at Columbia University in New York in collaboration with scientists at the University of Hong Kong, examined whether antibodies from 54 fully vaccinated Pfizer / BioNTech AstraZeneca and Johnson & Johnson can neutralize Omicron in the lab. The 15 had also received a booster dose of mRNA vaccine, while both had also been treated with Covid-19 in the past.
Antibodies from all vaccines were found to have significantly reduced efficacy in neutralizing Omicron compared to the other variants. Covid-19 recovered antibodies are even less effective at killing Omicron, which puts them at risk for re-infection.
Those who received a third dose of mRNA vaccine (Pfizer / BioNTech or Moderna) are better protected than those who have taken two doses, but in their own case the antibodies after the booster dose have a reduced neutralizing ability against Omicron. As Dr. Ho puts it, “Even a third dose may not adequately protect against Omicron infection, but of course one should do so, as it may increase one’s immune system.”
Regarding monoclonal antibodies, which can prevent coronavirus patients from becoming seriously ill, the study in 19 of them found that everything that is already in use, as well as most of those in development, is much less effective against Omicron. or do not “work” at all. Among them were REGN10987 (imdevimab), REGN10933 (casirivimab), COV2-2196 (tixagevimab), COV2-2130 (cilgavimab), LY-CoV555 (bamlanivimab), CB6 (etesevimab), Brii-196 (amubarvimab) (romlusevimab) and S309 (sotrovimab). Only the latter as well as romlusevimab were found to retain greater neutralizing capacity.
The researchers note that “Omicron is now showing the most complete escape from neutralizing antibodies ever seen by scientists.” Thus, Ho estimated that new vaccines and therapies should be developed. As he said, “it is not too much to think that the SARS-CoV-2 coronavirus is now only one or two mutations away from becoming completely resistant to current antibodies, either the monoclonal ones used as therapies or the antibodies produced by vaccination or infection with previous variants “.
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