Scientists test mRNA technology for universal flu vaccine

An experimental vaccine was found to potentially open a pathway to a universal flu shot that might help prevent future pandemics, according to a US study.

In initial tests in mice and ferrets, the two-dos vaccine provided broad protection against all 20 known influenza A and B virus subtypes,

The vaccine employs the same messenger RNA (mRNA)technology used in the COVID-19 shots developed by Pfizer with BioNTech, and by Moderna.

It delivers tiny lipid particles containing mRNA instructions for cells to create replicas of so-called hemagglutinin proteins that appear on influenza virus surfaces.

A universal vaccine would not mean an end to flu seasons but would replace the guesswork that goes into developing annual shots months ahead of flu season each year.

According to the study leader Scott Hensley of the University of Pennsylvania School of Medicine, the idea is to have a vaccine that provides give people with a baseline level of immune memory to diverse flu strains, so that there will be far less disease and death when the next flu pandemic occurs.

Unlike standard flu vaccines that deliver one or two versions of hemagglutinin, the experimental vaccine includes 20 different types in the hope of getting the immune system to recognize any flu virus it might encounter in the future.

The vaccine reduced signs of illness and protected them from death even when the ferrets were exposed to a different type of flu that is not in the vaccine, the researchers said.

However, Adolfo García-Sastrem, director of the Institute for Global Health and Emerging Pathogens at Mount Sinai Hospital in New York, warned that they cannot be sure of the new vaccine’s protective capacity against all subtypes of influenza viruses until clinical trials in volunteers are done.