WHO Calls Omicron Variant A 'Very High' Global Risk, And Has Been Reported In More Than 60 Countries

Illustrasi markas pusat WHO. (Wikimedia Commons / Thorkild Tylleskar)

JAKARTA - The World Health Organization (WHO) says the Omicron variant of the coronavirus has been reported in more than 60 countries, posing a 'very high' global risk with some evidence of being able to evade vaccine protection, although clinical data on its severity are limited.

Considerable uncertainty surrounds Omicron, which was first detected last month in southern Africa and Hong Kong, whose mutation could lead to higher transmission and more cases of the COVID-19 disease, the WHO said in a technical briefing issued on Sunday.

"The overall risk associated with the new variant of concern to Omicron remains very high for a number of reasons," the WHO said, repeating its first assessment on November 29, citing Reuters December 13.

At least one patient has died in Britain after contracting the Omicron variant, British Prime Minister Boris Johnson said on Monday.

The WHO said there were early signs that people who were vaccinated and previously infected would not build up sufficient antibodies to ward off infection from the Omicron variant, resulting in high transmission rates and "severe consequences".

It is unclear whether the Omicron variant is inherently more infectious than the globally dominant Delta variant, the WHO said.

Confirming the WHO assessment, Oxford University researchers published a laboratory analysis on Monday that noted a substantial reduction in neutralizing antibodies against the Omicron variant, in people who had had two doses of the COVID-19 vaccine.

While the antibody defenses of the AstraZeneca and BioNTech/Pfizer vaccine programs have been compromised, there is hope that T-cells, the second pillar of the immune response, can prevent severe disease by attacking infected human cells.

Some vaccine recipients did not produce measurable neutralizing antibodies against the Omicron variant, the Oxford researchers said. One of them, Matthew Snape, said it was not yet clear how markedly the decline in vaccine efficacy would be in the real world.

"We don't know how much neutralizing antibody is sufficient. We still haven't really determined what the threshold of protection is," Snape said, adding the best advice for the unvaccinated is to look for an initial dose and for those vaccinated to get a booster shot.

The Oxford researchers say there is no evidence yet that the Omicron variant causes more severe disease.

Their findings are broadly in line with another laboratory analysis last week of the blood of twice-vaccinated individuals, conducted by researchers at the Medical University of Innsbruck, Austria.

The analysis also noted a significant reduction in antibodies reacting to the Omicron variant, with many blood samples showing no response at all.

Both the Innsbruck and Oxford teams said they would extend their research to those who had three shots of the vaccine.

Meanwhile, Pfizer and BioNTech said last week that two injections of their vaccine may still protect against severe disease, because the mutation is unlikely to evade the T-cell response.

They also said the third booster injection restored a level of antibody protection against the Omicron variant comparable to that provided by the two-injection regimen against the original virus identified in China.

The WHO cites preliminary evidence that the number of people re-infected with the virus has risen in South Africa.

While initial findings suggest Omicron may be less severe than the Delta variant, more data is needed to determine whether Omicron is inherently less dangerous, he said.

"Even if the severity is potentially lower than the Delta variant, it is predicted that hospitalizations will increase as a result of increased transmission. More hospitalizations could burden the health system and lead to more deaths," he said.

More information is expected in the coming weeks, he added, noting the time lag between infection and results.