Public Health

WHO says Omicron variant could change the course of the Covid pandemic

An employee at a test station in the city center takes a swab from a woman. In Lower Saxony, stricter corona rules apply in many areas.

Hauke-Christian Dittrich | Image Alliance | Getty Images

The World Health Organization said Wednesday that the heavily mutated omicron variant of Covid-19 could change the course of the pandemic.

The exact effects are “still difficult to assess,” said WHO Director General Tedros Adhanom Ghebreyesus at a media talk from the group’s Geneva headquarters. Scientists around the world are trying to find out how contagious and deadly the mutated virus has become.

“Certain features of Omicron, including its global distribution and large number of mutations, suggest that it could have a major impact on the course of the pandemic,” Tedros said.

Genetic changes in the virus affect its virulence, suggesting that it could be significantly more contagious than previous strains, according to the WHO.

Too early to tell

Maria Van Kerkhove, WHO technical director for Covid-19, said preliminary evidence from South Africa might suggest Omicron is milder than the Delta strain but it is “too early to conclude that fact”. Patients in the country with milder disease may not have gone through the full course of infection, she added.

“It’s too early to say that,” Van Kerkhove said during the briefing. “I just wanted to warn of any conclusions about the severity of Omicron.”

However, she found that at-risk patients who are older, not vaccinated, or have underlying medical conditions are at a much higher risk of developing a serious illness.

WHO’s remarks come when the variant of Omicron, first identified in southern Africa, was found in 57 countries around the world.

New cases have “plateaued” worldwide in the past week, added the WHO. More than 4 million new confirmed cases have been reported worldwide, similar to the previous week’s numbers.

However, the number of deaths worldwide rose 10% in the past week, the WHO report found. Over 52,500 new deaths have been reported.

Effects on vaccines

On Tuesday, South African scientists published a small preliminary study on the effect of Omicron on vaccine effectiveness.

The variant was found to significantly reduce the antibody protection produced by the Pfizer and BioNTech vaccine. However, the scientists found that people who have recovered from the virus and received a booster vaccination are likely to have more protection from serious illnesses.

WHO chief scientist Dr. Soumya Swaminathan said at the briefing that it was premature to conclude that this “reducing neutralizing activity would result in a significant decrease” in vaccine effectiveness.

“We don’t know because, as you know, the immune system is much more complex,” said Swaminathan. “There are T cells, there are memory B cells, and what we really need now is a coordinated research effort, not jumping to conclusions, you know, study after study.”

Earlier this week, Pfizer CEO Albert Bourla said the company could develop a vaccine targeting the new variant by March 2022 if needed. He noted that it will take a few weeks to see if the current vaccines offer adequate protection against Omicron.

The Senior Medical Advisor to the White House, Dr. Anthony Fauci told reporters Tuesday that scientists should have some data on the vaccine’s effectiveness against the new variant by the middle of next week.

“With Omicron we will be able to determine whether antibodies, which are induced by all vaccines, lose their effectiveness or not,” said Fauci, referring to studies that examined both live viruses and “pseudoviruses”. “We also conduct animal studies to assess immune protection and the effectiveness of antiviral agents.”

Distribution in Europe

According to the EU health authority, Omicron was found in 21 countries in the European Union and the European Economic Area on Wednesday.

The European Center for Disease Prevention estimates that the variant could become the dominant strain in Europe sometime between January and March, depending on how much faster it spreads than Delta.

For example, if 1% of the current Covid cases in Europe can be traced back to the new variant and it is spreading more than twice as fast as Delta in the EU as in South Africa, it could possibly become dominant there by January 1st with more than 50 % of all new infections, according to the agency’s mathematical modeling. If it spreads 30% faster than Delta, it will be until March 1 before it overtakes other variants in Europe, the agency said in its analysis that examined these hypothetical situations.

“Omicron’s greater growth advantage over the Delta [variant of concern] and the more prevalent it is in the EU / EEA, the shorter the expected time for Omicron’s VOC to cause the majority of all SARS-CoV-2 infections, ”said a statement from the European Center for Disease Prevention.

However, the agency found that their estimates are “rough” and based on several assumptions about the Omicron variant. Results will depend on, among other things, “many as yet unknown factors” about omicron transmissibility, the escape of vaccine immunity, and the escape of natural immunity.

The agency’s analysis was cited in a WHO report released on Wednesday.

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