Could the omicron variant cause a milder disease?

The variant omicron, which is spreading in southern Africa and has been detected in more than 30 countries, has raised fears that it could significantly undermine the effectiveness of vaccines against COVID-19.

However, as scientists rush to understand all the consequences of omicron, some also wonder if this new version of the coronavirus could cause milder illness than its predecessors. While they caution that it is too early to draw conclusions, here is what is known so far:

What does the data show?

Evidence from early cases of the new variant is limited.

Among the 70 reported cases 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 published Thursday by the European Center for the Prevention and Control of The diseases.

There were no cases of serious illness, hospitalization or death. However, the European agency said it needs data from hundreds of cases to accurately assess complications from the disease, which could take several weeks.

Furthermore, most of the cases detected in Europe so far have occurred in younger people who were fully vaccinated, making them less likely to suffer from a serious illness.

In South Africa, where the daily number of reported COVID-19 cases doubled on Wednesday to 8,561, symptoms in reinfected 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 that many of the South African patients were initially among young college students,” said Dr. Carlos Del Rio, an infectious disease expert at Emory University. in Atlanta, during an online information session from the Infectious Diseases Society of America.

Is omicron a “less suitable” version of the coronavirus?

As data on infections in the field continue to emerge, scientists are conducting laboratory studies to decipher omicron.

The variant has about 50 mutations that have not been seen before in combination, including more than 30 mutations in the spike protein that the coronavirus uses to adhere to human cells. The vaccines being used target that protein.

“Normally, when viruses accumulate a lot of mutations, they lose some fitness,” said Dr. John Wherry, director of the Penn Institute of Immunology in Philadelphia. Certain omicron mutations can affect the virus’s ability to divide, changing the behavior of the spike protein, he noted.

Some scientists have theorized that omicron may have developed over a few months in an immunosuppressed individual, such as an HIV patient in southern Africa. If so, “the virus adapted so as not to kill that host,” Wherry said.

There are other theories that the most recent variant evolved from an animal host.

Will omicron become the dominant variant?

The other central question surrounding omicron is whether it will outperform the delta variant, which continues to account for the vast majority of known infections worldwide.

If omicron becomes the dominant variant but causes milder illness, it could mark a tipping point for the virus to eventually become a seasonal threat, like the flu, said Sumit Chanda, infectious disease researcher with the Department of Immunology. and Microbiology from Scripps Research in San Diego.

The European Union public health agency reported last Thursday that the omicron variant could be responsible for more than half of all COVID-19 infections in Europe within a few months.

While omicron is being investigated, disease experts say that people should remain vigilant against the coronavirus, getting vaccinated initially or receiving booster shots, as well as wearing masks in closed or crowded places, ventilating rooms and washing their hands.