A team of Australian and Japanese scientists has uncovered a protein particle within the SARS-CoV-2 virus that could form the basis of more durable and protective COVID-19 vaccines.
Researchers from La Trobe University and Kumamoto University found that the immune system mounts a strong response to an internal protein of the virus, one that mutates far less frequently than the spike protein targeted by existing vaccines. Their findings, published in Nature Communications, suggest that this internal target could be harnessed to develop next-generation vaccines that remain effective as the virus continues to evolve.
The study showed that fragments of the internal protein, known as peptides, appear on the surface of infected cells with the help of an immune molecule called HLA-C. Killer T cells then use these markers to identify and destroy the infected cells.
Distinguished Professor Stephanie Gras, Deputy Director of the La Trobe Institute for Molecular Science (LIMS), said the discovery offered a promising alternative to vaccines that rely solely on the fast-changing spike protein. “Currently, vaccines target the spike proteins that decorate the surface of the virus – but they mutate frequently as they are constantly under pressure by our immune cells, which means we might need a new vaccine for each new variant,” she said.
“We found that the killer T cells, which also fight infection, can be activated by a protein that forms a part of the shell that protects the virus’s genetic material, like the yolk of an egg. Because this protein is inside the virus, it mutates much less frequently – knowledge which could guide the development of vaccines and therapeutics that are still effective as the virus evolves.”
A longer-lasting vaccine, Professor Gras noted, could reduce the need for repeated boosters and help limit the risk of Long COVID. “The more people get vaccinated, the more we’re protecting the population, which helps to reduce the virus’s death toll and the impact of the infection itself. But there is more than just COVID – we now know that about 10 per cent of the population is impacted by Long COVID and the more you catch the virus, the more likely you can develop Long COVID.”
>The study was led by Professor Gras, Dr Demetra Chatzileontiadou, Dr Janesha Maddumage, and PhD candidate You Min Ahn from La Trobe’s School of Biomedicine, Agriculture and Environment. It was supported by grants from the National Health and Medical Research Council (NHMRC) and the Medical Research Future Fund (MRFF), with collaboration from Associate Professor Chihiro Motozono and Yoshihiko Goto of Kumamoto University, and data collected at the Australian Synchrotron.
Professor Gras will now lead a new La Trobe University research centre focused on understanding Long COVID and other chronic post-viral conditions such as ME/CFS and multiple sclerosis. The Post-Acute Viral Infection diseases Group (PAVING) Centre of Research Excellence has secured $3 million in federal funding from the NHMRC to explore the causes of these conditions and develop potential interventions.
This breakthrough, combining fundamental immunology with a clear clinical goal, could mark the start of a new chapter in the fight against COVID-19, one where vaccines not only keep pace with the virus, but stay ahead of it.