Universal flu virus killer could be a step closer after breakthrough cell research

Scientists might be a step closer to finding a silver bullet that kills all flu viruses, after confirmation of the role of a type of white blood cell in fighting the disease.

In a paper published in the latest issue of journal Nature Communications, a team of Chinese and Australian researchers reported for the first time that the cells, called CD8+ T, helped flu victims recover much faster by memorising different strains of the disease.

“Our extraordinary breakthrough could lead to the development of a vaccine component that can protect against all new influenza viruses, with the potential for future development of a one-off universal flu vaccine shot,” said co-author Katherine Kedzierska, associate professor at the University of Melbourne.

Extensive studies on T-cell based vaccines have been done by many research groups around the world, and this latest study could significantly speed up the development process.

The breakthrough came after scientists observed patients with abundant and high quality CD8+ T cells during the H7N9 influenza virus outbreak in China two years ago.

The H7N9 was one of the deadliest strains of avian flu ever, with nearly all humans infected by it having to be hospitalised and one third of all patients dying.

What caught researchers’ attention was the speedy recovery of some patients, especially those discharged within two weeks.

Traditional investigations, such as analysing the presence of antibodies produced by another type of white blood cell, known as B cells, could not fully explain the phenomenon.

“After collecting samples from infected patients we found that people who couldn’t make these T cell flu assassins were dying,” Kedzierska said.

Unlike B cells, which could only deal with specific viral strains, the CD8+ T cells retained memories of viruses they encountered and used those as a reference to identify new viruses.

“However they mutate, flu viruses share some common features. A strong and powerful T cell may use these features to eliminate mutants,” said professor Wan Yanmin, a member of the Chinese team at the Shanghai Public Health Clinical Centre.

One remaining issue was to understand better the underlying mechanism of T cells in the flu killing process.

“We still don’t fully understand the process. The effect of T cells seems to vary from one person to another, and it may have to do with a mechanism more sophisticated than we know,” Wan said.

Another challenge was to find effective ways to boost the flu killing T cells in human bodies. While a vaccine could be an option, scientists were also exploring other approaches such as medicines and genetic therapies.

Wan said a vaccine could be problematic as it would not be a preventative measure as traditional jabs are.

“A T cell shot would not prevent you from being infected. Unlike a traditional vaccine, you would still get sick, which may affect public acceptance. But the T cell could save your life, and you would recover faster,” he said.