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expert reaction to five studies of the effectiveness of vaccines and antibody treatments against Omicron

Five studies published in Nature look at the effectiveness of vaccines and antibody treatments against the Omicron variant of SARS-CoV-2.


Prof Adam Finn, University of Bristol, said:

“Quick look suggests these papers say what we already knew ie most anti-S neutralising antibodies don’t work vs omicron. Means monoclonals mostly useless now and boosters of wuhan vaccine only way to achieve antibody mediated protection by achieving high titres – but that protection won’t last long. T cell immunity likely to be ok though so that may help explain why fewer people ending up in hospital despite vast numbers of cases. There’s light at the end of the tunnel but quite a bit more darkness before we reach it.”


Prof Sir Martin Landray, Professor of Medicine & Epidemiology, Oxford Population Health and Co-lead, RECOVERY trial, said:

“The data suggest that many of the monoclonal neutralising antibodies have substantially weaker activity against the omicron variant. Critically, for the sickest patients – those admitted to hospital – the combination of casirivimab and imdevimab (which together make up the Ronapreve combination treatment) appear to be profoundly impacted. Previously, the RECOVERY trial demonstrated that the Ronapreve treatment improved survival for patients admitted to hospital but who had not mounted an effective antibody response of their own (so-called ‘seronegative’). For the past few months, Ronapreve has been available for use in patients admitted to NHS hospitals. However, this treatment is not going to be of any help to the rapidly increasing number of patients affected by the omicron variant. NHS advice has already been updated to reflect this – but currently there is no monoclonal neutralising antibody treatment proven to be effective in patients admitted to hospital because of COVID-19.

“Sotrovimab, the monoclonal antibody developed by GSK and Vir, appears to remain effective against the omicron variant. It is now being used for patients with mild COVID (those who don’t require oxygen) and who are at increased risk of developing severe disease (e.g. those with cancer). As of next week, the RECOVERY trial will be assessing whether sotrovimab is effective in improving survival, shortening hospital stay, and reducing the need for mechanical ventilators during this current wave of the pandemic.”

More information on sotrovimab in the RECOVERY trial is available here:


Dr Clive Dix, former Chair of the UK Vaccine Taskforce, said:

“Some of the headlines and interpretations are misleading. Decrease in antibody neutralisation is not the same as vaccine effectiveness. We have seen a progressive loss of antibody neutralisation as we moved through alpha, beta, gamma and delta. That no doubt leads to decrease in effectiveness against transmission and infection but to date the vaccines all protect against severe disease (including hospitalisation) and death. So we should be optimistic that effectiveness against that latter two measures will remain. This is almost certainly due to a good durable cellular immune response which these studies do not analyse.”



All our previous output on this subject can be seen at this weblink:



Declared interests

Prof Martin Landray: “In the past, Regeneron provided casirvimab+imdevimab and Roche provided tocilizumab for the RECOVERY trial. GSK and Vir are now providing sotrovimab for the RECOVERY trial. RECOVERY is funded by a grant from the Medical Research Council and National Institute for Health Research.”

None others received.



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