The flu vaccines don’t offer the same level of protection as we’d like against the most widely circulating strain of influenza according to a new study says however, the vaccines can still keep people from suffering severe illness who are infected.
The vaccines were designed long in advance to fight the flu strains expected to dominate the United States during the 2021-22 flu season H3N2, H1N1, and two strains of influenza B.
H3N2, the main strain, has mutated in a manner that means the flu vaccines don’t match up against it very well, Scott Hensley, PhD, a professor of microbiology at the University of Pennsylvania who led the study, told CNN.
He added, “From our lab-based research, it looks like there is a significant difference.”
This mismatch could have contributed to the spread of the flu on college campuses.
An outbreak at the University of Michigan affected more than 700 people, with around 26 percent of those who were found positive for the virus had been vaccine-vaccinated against the flu according to CNN.
Though vaccines may not stop H3N2, it appears like they’ll prevent serious infection from this strain, researchers said.
“Studies have demonstrated that seasonal influenza vaccines have a tendency to prevent deaths and hospitalizations, even in years where there are large antigenic mismatch,” they wrote on medRxiv an online site that publishes reports that are yet to be peer-reviewed.
The news about H3N2 is concerning because the U.S. experienced an easy flu season in 2020-21. This was apparently due to COVID safety measures that reduced the spread of the flu virus.
Researchers wrote that “population immunity to influenza viruses is probably low because these viruses haven’t circulated widely during COVID-19 pandemic.” “Global influenza virus transmission has been reduced by mask wearing and social distancing as well as less international travel,” the researchers concluded.
“Once COVID-19-related restrictions are eased or lifted it is possible that influenza viruses will spread widely due to lack of immunity to infection in the population in the last two years.”
In the season of 2019-20 more than 22,000 people in the U.S. died from the flu. Last year, the number of deaths dropped to around 700 for the 2020-21 season.
Researchers are now considering whether the U.S. will go through another easy flu season or if it will experience a “twindemic,” with people getting sick from the flu and COVID.
Sources
medRxiv. “Antigenic and viral properties of the H3N2 variant that will likely dominate 2021-2022 Northern Hemisphere flu season.”
CNN. “Flu vaccines don’t match with the predominant strain of the flu virus that circulates Researchers find.”
Content Source: https://www.medscape.com/viewarticle/965073?src=rss
