By Nancy Lapid
(Reuters) – An experimental vaccine offers broad protection against 20 known subtypes of influenza A and B viruses in preliminary tests in mice and ferrets, which could pave the way for a universal flu vaccine that could help prevent future pandemics, according to the American. study that was published. Thursday.
The two-dose vaccine uses the same messenger RNA (mRNA) technology used in Pfizer, BioEntech and Moderna's COVID-19 injections. It delivers tiny lipid particles that contain mRNA instructions for cells to create a replicating protein called hemagglutinin on the surface of the flu virus.
A universal vaccine would not spell the end of flu season, but it would replace the guesswork involved in developing the annual vaccine months before flu season each year.
"The idea here is a vaccine that would give people initial immunological memory against different strains of flu, so there would be far fewer illnesses and deaths in subsequent flu pandemics," said study leader Scott Hensley of the School of Perelman. In a statement from the Department of Medicine at the University of Pennsylvania.
Unlike standard flu vaccines, which provide one or two versions of hemagglutinin, the experimental vaccine contains 20 different types to trick the immune system into recognizing any flu viruses it may encounter in the future.
In laboratory tests, the immune systems of vaccinated animals recognized the hemagglutinin protein and defended against 18 different strains of influenza A and two strains of influenza B. Vaccine-induced antibodies remained unchanged for at least four months, according to a report published in the journal Sciences.
The vaccine reduced symptoms of the disease and prevented death, even when the ferrets were infected with a different type of flu that was not in the vaccine, the researchers said.
Both Moderna and Pfizer have mRNA flu vaccines in late-stage human trials, and GSK and its partner CureVac are testing an mRNA flu vaccine in early-stage human safety trials. These vaccines are said to only protect against four recent flu strains, but in theory they can be changed every year.
The universal flu vaccine, if successful in human trials, will not necessarily prevent infection. The goal, Hensley said, is to provide long-lasting protection against serious illness and death.
There are questions about evaluating the efficacy of vaccines and potential regulatory requirements against possible future viruses that are not currently in circulation, write Alison Kelvin and Daryl Falzarano of the University of Saskatchewan. Canada, Studies in a comment.
Adolfo Garcia-Sastrem, director of the Institute for Global Health and Emerging Pathogens at Mount Sinai Hospital, said the promising results of the new vaccine "point to a protective ability against all subtypes of the influenza virus, something we cannot be sure until clinical trials in volunteers are done. have been completed,'' he said in a statement from New York.
(Reporting by Nancy Lapid; Editing by Christine Soares and Bill Berkrot)