Melbourne researchers have discovered COVID-19 patients lack killer T cells, important for fighting viral infections, compared to influenza or glandular fever patients.
The team from the Doherty Institute for Infection and Immunity looked into 22 COVID-19 samples from patients who experienced asymptotic, mild, and moderate cases.
Their research focussed on CD8 T cells, known as 'killer T cells' which Doherty Institute PhD student Jennifer Habel said are "integral to mounting an effective and rapid recovery from viruses such as influenza".
The study found that the key immune cells weren't stimulated well enough to produce the numbers of cells needed to fight COVID-19.
"The magnitude of the killer T cells was only five times higher than those of the naive immune cells," Habel said.
"To give that perspective, it's 10 times lower than what we see during an influenza or glandular fever response."
The team also found alongside a lack of numbers, the T cells often remained inactive as if they hadn't been exposed to a virus at all.
World-leading influenza immunology researcher and leader of the study Professor Katherin Kedzierska said the findings surrounding T cells are important as it provides vital information for creating a vaccine.
"Knowing the specific T cells and proteins to target will inform the design of an effective vaccine," Kedzierska said.
"This research shows that potentially if a vaccine was able to prime the immune system of killer T cells and then boost them a short time later, the immune response is likely to be much more robust."
