Influenza, towards universal vaccine: test on ‘joker’ against 20 viruses

It is a mRna product: it produced high levels of antibodies in mice and ferrets

Scientists consider it a “new step towards the universal flu vaccine”. It was developed by researchers at the University of Pennsylvania, USA, and is an mRna product that contains antigens from all 20 known subtypes of influenza A and B viruses. With its lipid nanoparticles on which the messenger RNA travels, this The vaccine, in tests conducted by researchers Claudia Arevalo and colleagues, produced high levels of cross-reactive antibodies and subtype-specific antibodies in mice and ferrets and could protect the animals from disease symptoms and death after infection with influenza strains both antigenically matched and mismatched. The work of the study authors is published in ‘Science’.

Experts explain the sense of having wide-ranging vaccines. Even with increased global surveillance, they note, it’s hard to predict which flu strain will cause the next pandemic. This vaccine for 20 influenza virus subtypes is important because the strategy used to make it could serve as the basis for universal flu vaccines, which are needed for the reasons highlighted by the researchers. Arevalo and colleagues’ approach differs from previous attempts to create a universal flu vaccine because it includes specific antigens for each viral subtype, rather than just a smaller set of antigens shared among all.

In the wake of the success of anti-Covid mRna vaccines, researchers have prepared 20 different mRna encapsulated in nanoparticles, each of which codes for a different hemagglutinin, i.e. a highly immunogenic viral protein that helps the virus enter cells. After 4 months of vaccination, antibody levels remained mostly stable in the mice, the authors report.

In animals, multivalent protein vaccines produced using more traditional methods elicited fewer antibodies and were less protective than multivalent mRNA vaccines, they noted.

In a related article, virologists Alyson Kelvin and Darryl Falzarano discuss the research findings, noting that “questions remain about the regulation and approval path for such a vaccine targeting viruses with pandemic potential but not currently circulating in humans.” “.