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.
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 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.
As financial markets welcomed the signs that Omicron might be less severe than feared, global shares extended a rally on Thursday while safe-haven bonds and currencies eased. Beyond western Europe, the Delta variant continued to spread.
The UK data on hospitalisations was supported by a study released on Wednesday by South Africa’s National Institute for Communicable Diseases (NICD). But NICD researchers included several caveats.
“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.
