New review suggests T cells are more robust against ‘Omicron breakthroughs’ than antibodies, offering fresh insights for COVID-19 vaccine development.

Despite significant vaccination efforts, the SARS-CoV-2 virus continues to evolve, with variants and subvariants like Omicron, Pirola, and Juno emerging, leading to new waves of infection.

Bringing together the findings of two key studies, a new review highlights how T cells could play a crucial role in protecting us from these emerging variants.

The review is published today in Cell Host & Microbe by Professor Danny Altmann from the Department of Immunology and Inflammation and Professor Rosemary Boyton from the Department of Infectious Disease.

During the early stages of the pandemic, neutralising antibodies were considered to be the primary defence mechanism against COVID-19. But as the virus continues to evolve, it has become better at evading these antibodies.

However, new research shows that memory T cells – central players in the body’s adaptive immune response to recurring viral infections – are more effective at recognising and fighting the virus’ changes compared to antibodies. This is especially true in people with hybrid immunity, obtained through vaccination and natural infection.

The researchers explain that given the burden of breakthrough cases and their impact on healthcare systems, the findings have important implications for future vaccine development strategies. They suggest that boosting T cell responses could offer stronger and longer-lasting protection against different strains of the virus.

Professor Danny Altmann, co-author of the review and Professor of Immunology, said: "This recent work reminds us that, much as we try and put the pandemic behind us, we’re still very much locked in a fast-moving arms-race against the virus. We need to be alert to keep reappraising strategies, making it important to understand these different immune mechanisms, including T cells” 

While the findings are encouraging, the authors of the review emphasise that more research is needed to fully elucidate the role of T cells in immunity to the virus’ different forms.