With the omicron variation, an unsung arm of the immune system appears to guard against serious disease even as antibodies weaken, which may explain why hospitals haven’t been hit by a record surge of infections.
In independent investigations from Erasmus University in the Netherlands and the University of Cape Town in South Africa, T cells, the body’s weapon against virus-infected cells, were primed sufficiently by vaccination to protect against omicron.
The findings might explain why the omicron outbreak hasn’t resulted in a spike in mortality from South Africa to the United States and the United Kingdom. T cells, unlike antibodies, can target the whole spike protein of the virus, which is very identical even in the severely altered omicron.
While antibody responses to omicron were lower or nonexistent in 60 vaccinated health-care workers compared to the beta and delta variants, T cell responses were largely unaffected, “potentially balancing the lack of neutralizing antibodies in preventing or limiting severe Covid-19,” according to the Dutch researchers.
Patients who had recovered from Covid or been vaccinated with injections from Pfizer Inc. and partner BioNTech SE or Johnson & Johnson were studied by the University of Cape Town’s Institute of Infectious Disease and Molecular Medicine. They discovered that 70% to 80% of the T cell responses they tested were resistant to omicron.
Evidence that the new strain can degrade vaccination protection has emerged in recent weeks, prompting governments to urge for booster injections to enhance the amount of antibodies that can fight the variety.
Immune defense, on the other hand, is multi-layered. T lymphocytes destroy infected cells, stopping the virus from spreading and causing greater sickness, according to Wendy Burgens of the University of Cape Town, who tweeted about the findings on her Twitter account Virus Monologues. “They can’t stop you from getting infected, but they can help you minimize the damage,” she explained.
T cells are white blood cells that have the ability to recall prior infections, destroy virus-infected cells, and elicit antibodies to aid in defence. People who were infected with another coronavirus that caused the SARS pandemic in 2003, for example, had a T-cell response to the sickness 17 years later.