How Close Have Scientists Come to Creating a Universal Flu Vaccine?
Despite efforts by researchers and health workers, the flu kills tens of thousands of people in the U.S. alone, and hospitalises hundreds of thousands more.
This is largely due to the difficulty found when predicting what strains of the influenza virus health officials should try to combat in a given season, reports Scientific American.
However, a team of scientists from the U.S. and China have revealed that they have designed a vaccine that could take away this guesswork, in turn boosting the immune system’s capacity to combat many viral strains.
The group, led by the University of California have revealed that they may have created the “Goldilocks” of flu vaccines, one that manages to trigger a very strong immune response without making infected animals sick.
This new vaccine even fuels a strong reaction from disease-fighting white blood cells called T cells, something not seen in current flu vaccines. This development is very important because a T cell response will likely confer longer-term protection than current inoculations do and defend against a variety of flu strains.
“This is really exciting,” commented Kathleen Sullivan, chief of the Division of Allergy and Immunology at The Children’s Hospital of Philadelphia, who was not involved in the work.
The team’s flu approach uses a live virus, so it is able to elicit both an antibody response and T cell immunity, at least in lab ferrets and mice.
“It has the magic of both great antibody response and inducing a strong, strong T cell response that will be a safety net – so if a virus breaks through the first line of defense, you will have T cell to make sure you don’t get very sick,” added Sullivan.
They went on to dissect the flu virus in lab dishes and tested how different mutations in each segment responded when exposed to interferon, a protein released by the body when viruses attack that helps keep flu infections in check. The scientists then were able to identify which mutations made the virus most likely to provoke action from protective interferon’s. After learning that information, the researchers designed a mutant flu strain that was powerful enough to replicate well but highly susceptible to our body’s own ability to control the virus.
The inoculation looks promising in both ferrets and mice, the most commonly used models of influenza infection. If the approach can be used to work as well in humans, the authors say that their invention could negate the need for annual flu shots. The scientists believe that because they included eight mutations in their lab-made viral strain, it is unlikely the virus will revert back to its original, more dangerous form.
In addition, there may also be other applications from this work. Researchers could take over viruses apart in the lab, scour them for important mutations and create vaccines against an array of other infections.
However, a number of obstacles stand in the way of this becoming a future universal flu vaccine for humans any time soon, expressed scientists from The Scripps Research Institute. Although the team discovered there was some cross-protection across a small set of flu strains – H1N1 and H3N2 subtypes – that may not hold true across all forms of the flu.
Sullivan noted that researchers would need to examine if triggering a robust immune response to the virus puts people at risk, because a frenzied immune system response is what destroys lung tissue and sometimes even proves deadly when people are infected with H5N1, a type of avian flu. “There are lots of practical questions about rolling this out for humans,” she concluded. “But this is hugely innovative and exciting.”