Omicron may promote weakened immunity, blood tests show

Ottawa-Immune to COVID-19 between vaccinated adult Canadians and those already infected with the virus is declining across the population, blood donated blood tests have been found.

Tests of approximately 9,000 blood donation samples from across Canada show that antibodies in the blood that fight the virus are reduced in October for all age groups, and experts say that immunity may continue to decline in November and December. It says it is expensive.

However, the head of the government’s COVID-19 Immunity Task Force has stated that highly contagious variants of Omicron may provide “immunity dividends” that provide new protection against future infections. ..

Task Force scientists are now analyzing the degree of immunity provided by Omicron and the intracellular “memory of immune protection” that can cause future COVID-19 infections.

With a task force study of immune levels that informs government policies on booster shots, findings can influence when and how many people will do booster shots in the future.

In an interview, Dr. Tim Evans, Managing Director of the Task Force, who advises the government on responding to pandemics, said research on immunity by Omicron is currently a priority.

“Because of the vast majority of the population currently infected with Omicron, this is one of the Task Force’s priorities to understand what the immune dividend from infection from Omicron is,” he said. I told the Canadian Press.

“If it is strong and persistent in terms of immunological memory, it can affect our thinking about the need and timing of boosters.”

“Our test system can’t keep pace,” Evans added, because Omicron is so popular nowadays.

“Therefore, the numbers (including Omicron) are very underestimated. There is a large majority of the population currently infected with Omicron,” he said.

Canadian Blood Services tests the presence of antibodies that fight COVID-19 in blood samples from donors over the age of 17 every month. After the second vaccination of Canadians, it was detected that their immunity improved significantly last summer. However, in September, we noticed that antibodies capable of fighting the virus were declining in people over the age of 70.

The Canadian Blood Services Report, completed this week, analyzes blood donated in October and shows that immunity has diminished among all donors from the age of 17 to pensioners.

Sheila O’Brien, Associate Director of Epidemiology and Surveillance at Canadian Blood Services, said, “We are in a unique position to provide information on the presence of COVID-19 antibodies in large numbers of people across Canada relatively quickly.” ..

She said that antibodies that could fight the virus were significantly higher in vaccinated people than in unvaccinated people.

“Approximately two weeks after vaccination, antibody levels peak and then gradually decline,” she added.

Evans predicted that the weakened immunity measured in the blood would continue to appear in the November and December data. However, he said the Task Force will study whether more and more people are infected with Omicron and their immunity has improved.

The Task Force’s findings on weakened immunity have influenced the government to provide vaccine booster shots to vulnerable groups such as weakly immunized transplant patients and the elderly.

Dr. Bruce Mather, an immunological scholar and quasi-science director of the COVID-19 Immune Task Force, said that the body’s immune system has viral cell memory to fight even when blood antibody levels are low. Said that it can be mobilized. He said that those who were vaccinated, those who were infected with the virus, or both produced cell-mediated immunity.

“Other parts of the immune system are waiting and functioning as sentinels,” he said. “There is a T cell memory that helps fight the virus and a B cell memory that helps create a fresh group of antibodies.”

A professor at McGill University said the Task Force is currently studying this backup immune response and the immune response to the Omicron variant, which he said has 50 variants compared to the original COVID-19 virus. ..

This report by The Canadian Press was first published on January 6, 2022.