The Omicron variant, which is now spreading in southern Africa and detected in more than 30 other countries, has raised concerns that it could significantly compromise the effectiveness of COVID-19 vaccines.
Yet as scientists rush to understand the full consequences of Omicron, some also wonder if this new version of the coronavirus could cause milder disease than its predecessors. Although they warn that it is far too early to draw any conclusions, here is what is known so far:
What does the data show?
The evidence for the initial cases of the new variant is limited.
Among the 70 cases reported in Europe that included information on the severity of the disease, half of the patients had no symptoms and the other half had mild symptoms, according to a report released Thursday by the European Center for Prevention and Control. diseases.
There were no cases of serious illness, hospitalization or death. However, the European agency said it would need data on hundreds of cases to accurately assess complications of the disease, estimating it could take several weeks. In addition, most of the cases detected in Europe so far have been in younger people who were fully vaccinated, making them less likely to suffer from serious illness.
In South Africa, where the daily number of reported COVID-19 cases doubled on Wednesday to 8,561, symptoms of re-infected patients and those infected after vaccination appear to be mild.
“Some evidence from South Africa suggests that it may actually cause milder disease, but I caution you that a large number of South African patients were initially among young university students,” Dr Carlos Del Rio, infectious disease expert at Emory University in Atlanta, said Thursday during an Infectious Diseases Society of America online briefing.
Is Omicron a “less suitable” version of the coronavirus?
As data on real-world infections continues to emerge, scientists are conducting lab studies to decipher Omicron. The variant has about 50 mutations never seen in combination before, including more than 30 mutations on the spike protein that the coronavirus uses to attach to human cells. Vaccines currently in use target this spike protein.
“Usually, when viruses accumulate a lot of mutations, they lose some physical form,” said Dr. John Wherry, director of the Penn Institute for Immunology in Philadelphia. Certain mutations in Omicron can alter the ability of the virus to split, thereby altering the behavior of the spike protein, he said.
Some scientists have speculated that Omicron may have developed over a period of several months in an immunocompromised individual, such as an HIV patient in southern Africa. If so, “the virus has adapted not to kill this host,” Wherry said.
There are competing theories that the latter variant evolved from an animal host.
Will Omicron become the dominant variant?
The other central question surrounding Omicron is whether it will overtake the Delta variant, which still accounts for the overwhelming majority of known infections worldwide. If Omicron becomes dominant, but causes milder disease, it could mark a turning point for the virus to become a seasonal threat, like the flu, said Sumit Chanda, an infectious disease researcher at the Scripps Research Department of Immunology and Microbiology at San Diego.
The European Union’s public health agency said on Thursday that the Omicron variant could be responsible for more than half of all COVID-19 infections in Europe within months.
While research on Omicron is ongoing, disease experts say people need to stay vigilant against the coronavirus by getting either initial vaccines or boosters, as well as wearing masks in indoor or overcrowded environments, ventilating rooms. and wash your hands.