New hope as scientists discover killer T-cells CAN boost immunity against Omicron

KILLER immune cells can mount a robust attack against Omicron and will fight the strain when antibodies fail to, new findings show.

Scientists said the super-spreading variant was unlikely to evade T-cells, which are white blood cells produced after infection or vaccination.

They form part of hidden defences against the virus which are not as easily studied like antibodies are. 

Various studies have shown that antibodies, the body’s first line of defence against Covid, are not as strong against Omicron as they would be against other strains.

However, today’s findings add to a string of hugely positive studies about Omicron, including those that say it is milder.

The first official UK report revealed the risk of hospitalisation is 50 to 70 per cent lower than with Delta.

Covid booster jabs protect against Omicron and offer the best chance to get through the pandemic, health officials have repeatedly said.

The most recent study found an 81 to 88 per cent reduction in the risk of hospital admission after three doses compared to unvaccinated Omicron cases.

The Sun’s Jabs Army campaign is helping get the vital extra vaccines in Brits’ arms to ward off the need for any new restrictions.

T-CELL ATTACK

The new study was conducted by the University of Melbourne and Hong Kong University of Science and Technology (HKUST),

Due to Omicron’s huge number of mutations, it can sometimes slip past the antibodies created by vaccination or infection.

There is an abundance of mutations in its spike protein - the spike enables the virus to attach and enter cells in humans.

The spike protein was the primary target when Covid-19 vaccines were made. Therefore, variants with changes on the spike mean vaccines are less effective.

Scientists analysed fragments of proteins called epitopes in the spike protein of Omicron.

These have been found to be recognised by T-cells in recovered Covid-19 patients or after vaccination.

But among the epitopes that had the Omicron mutation, more than half were predicted to be visible to T-cells, study co-lead Ahmed Abdul Quadeer said.

The team’s findings, published in the peer-reviewed journal Viruses, suggest the immune system is capable of mounting a T-cell attack against Omicron.

University of Melbourne professor and co-leader of the research, Matthew McKay, said: “Even if Omicron, or some other variant for that matter, can potentially escape antibodies, a robust T-cell response can still be expected to offer protection and help to prevent significant illness.

“Based on our data, we anticipate that T-cell responses elicited by vaccines and boosters, for example, will continue to help protect against Omicron, as observed for other variants. We believe this presents some positive news in the global fight against Omicron.

“Despite being a preliminary study, we believe this is positive news.”

It adds to a growing body of evidence from research groups around the world who are also investigating T-cell responses to Covid.

It may also suggest that even if antibody responses are lower against Omicron than they were for Delta, T-cells are robust.

It comes after a study from South Africa, in which researchers exposed copies of the Omicron virus to T-cells from volunteers who had received vaccines or who had natural immunity.

"Despite Omicron's extensive mutations and reduced susceptibility to neutralizing antibodies, the majority of T cell response, induced by vaccination or natural infection, cross-recognizes the variant," the researchers reported.

"Well-preserved T cell immunity to Omicron is likely to contribute to protection from severe Covid-19.”