Vaccine manufacturers AstraZeneca, Novavax have said that their shots offered protection against Omicron, as British data suggested it may result in proportionally fewer hospitalisations than the Delta coronavirus variant, supporting the conclusions reached in South Africa.
On Thursday, AstraZeneca said, that a three-course dose of its Covid-19 vaccine offered protection against the variant, citing data from an Oxford University lab study.
The study, yet to be published in a peer-reviewed medical journal, showed that antibody levels against Omicron after the booster shot were higher than antibodies in people who had been infected with and recovered naturally from Covid-19.
Hours earlier, Novavax Inc had said that early data had showed its vaccine generated an immune response against Omicron. Novovax’s two-dose, protein-based vaccine was authorised for use this week by European Union regulators and the WHO.
It has yet to be approved by the United States.
Coronavirus infections have soared across much of the world as the highly infectious Omicron variant has spread, triggering new curbs in many countries.
However, World Health Organisation officials have stressed that it is too soon to draw firm conclusions about its virulence.
First identified last month in Southern Africa and Hong Kong, the variant has quickly become dominant in Britain, where daily infections have soared beyond 1,00,000.
Preliminary data had indicated that Omicron was more resistant to vaccines which had been developed before it’s emergence.
But according to researchers, increase in hospitalisations and deaths in Britain since Omicron took hold have been more gradual.
Researchers at University of Edinburgh who tracked 22,205 patients infected with Omicron, on Wednesday, explained that that the number of patients who needed to be hospitalised was 68% lower than they would have expected, based on the rate in patients with Delta.
Imperial College London researchers said that they saw evidence over the last two weeks, of a 40% to 45% reduction in the risk of hospitalisation for Omicron relative to Delta.
The UK data on hospitalisations was supported by a study released on Wednesday by South Africa’s National Institute for Communicable Diseases (NICD).
However, NICD researchers included several warnings. “It is difficult to disentangle the relative contribution of high levels of previous population immunity versus intrinsic lower virulence to the observed lower disease severity,” they wrote.
The WHO’s technical lead on Covid-19, Maria van Kerkhove, said that the UN agency did not have enough data to draw firm conclusions.
The data on Omicron was still “messy,” she told a briefing in Geneva on Wednesday.