The Omicron variant of COVID-19 is spreading rapidly throughout Great Britain and is likely to become the dominant form of the disease across the country by the middle of this month, the UK Health Security Agency says.
That projection mirrors what has been happening in South Africa, where the mutant strain was first identified and where fresh infections have been running at rates in exces of 20,000 cases a day.
New data from the UK confirms Omicron is more easily transmissible than other variants, the agency said on Friday in its latest variant technical briefing.
Other studies suggest that both the AstraZeneca and Pfizer vaccines are less effective in preventing symptomatic infections in people exposed to Omicron, though preliminary data show that effectiveness appears to rise to between 70 per cent and 75 per cent after a third booster dose.
The latest data shows 568 confirmed or probable Omicron infections as of December 8, up from just two only one week earlier.
If current trends continue, the UK will exceed one million Omicron infections by the end of December, the health security agency said.
“Once again, we urge everyone who is able to get a booster jab to come forward and do so,” Dr. Jenny Harries, the agency’s chief executive, said in the briefing paper.
While underscoring earlier warnings about the risks posed by the Omicron variant, the agency said the data should be treated with caution because the findings are based on early analysis of a small number of cases.
In particular, the agency said scientists don’t know how effective the vaccines will be in preventing severe disease in people exposed to the variant, though it is expected to be “significantly higher” than protection against mild infections.
South Africa’s massive surge
South Africa will offer booster doses of the Pfizer and Johnson & Johnson COVID-19 vaccines as the Omicron coronavirus variant drives daily infections towards record highs.
National medical authorities reported more than 22,000 new COVID-19 cases on Thursday, a record during a fourth wave of infections driven by the Omicron variant but still below a peak of more than 26,000 daily cases during the third wave driven by the Delta variant.
Health Minister Joe Phaahla said there were positive signs from early hospital data showing Omicron appears to be causing mainly mild infections.
Pfizer boosters will be available to people six months after they receive their second dose, with the first people becoming eligible late this month, the South Africa health department’s deputy-director general, Nicholas Crisp, has told a news conference.
J&J boosters, already available to health workers in a research study, will be rolled out to the general population soon, he said on Friday.
Glenda Gray, president of the South African Medical Research Council, said there were far more unvaccinated people among current hospital admissions.
On the Pfizer vaccine, she said: “We are seeing this vaccine is maintaining effectiveness. It may be slightly reduced, but we are seeing effectiveness being maintained for hospital admissions and that is very encouraging.”