AstraZeneca booster shots offer significant protection against Omicron: Researchers

London: Two vaccine manufacturers said their shots offered protection against Omicron, as UK data suggested it may cause proportionally fewer hospitalisations than the Delta coronavirus variant, supporting conclusions reached in South Africa. Coronavirus infections have soared across much of the world as highly infectious Omicron has spread, triggering new curbs in many countries. World Health Organization officials have said, however, that it is too soon to draw firm conclusions about its virulence.

First identified last month in Southern Africa and Hong Kong, the variant is quickly becoming dominant in much of western Europe including Britain, where daily infections have soared beyond 100,000. Preliminary data had indicated Omicron was more resistant to vaccines developed before it emerged. But increases in hospitalisations and deaths in Britain since Omicron took hold have been more gradual, researchers said.

University of Edinburgh researchers who tracked 22,205 patients infected with Omicron said late on Wednesday (December 22) that the number 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 they saw evidence over the last two weeks of a 40% to 45% reduction in the risk of hospitalisation for Omicron relative to Delta. Raghib Ali, senior clinical research associate at the University of Cambridge, said scientists had warned that, with the surge in UK cases, even a small proportion of hospitalisations could overwhelm the heathcare system. However, the UK data was encouraging and "may help justify the government`s decision not to expand restrictions on social gathering over Christmas in England," he said.

AstraZeneca, meanwhile, said on Thursday that a three-course dose of its COVID-19 vaccine offered protection against the variant, citing data from an Oxford University lab study. Findings from the study, yet to be published in a peer-reviewed medical journal, match those from rivals Pfizer-BioNTech, and Moderna. The study on AstraZeneca's vaccine, Vaxzevria, showed that after a three-dose course, neutralising levels against Omicron were broadly similar to those against Delta after two doses.

Hours earlier, Novavax Inc said early data showed its vaccine - authorised for use this week by European Union regulators and the WHO but yet to be approved by the United States - also generated an immune response against Omicron.