The experimental vaccine triggers an immune response against the influenza protein segment, which rarely mutates but is usually not visible to the immune system. In animals, the vaccine showed the production of widely neutralizing antibodies, proving its potential as a universal tool against influenza.
Most modern influenza vaccines consist of inactivated viruses coated with the protein hemagglutinin, which helps to bind to cells. After a vaccination, the immune system produces hemagglutininin-targeted antibodies and almost always targets the “head” protein while the other remains invisible to the immune system. This part of the protein actively mutates and that is why the annual flu vaccination targets different strains of the virus.
This is an unfortunate flaw that scientists have tried to correct, as an important advantage of the hidden hemagglutininine protein part is the rare exposure to mutations. Their work has been published on the website of the Massachusetts Institute of Technology.
“We don’t see the full picture yet, but for some reason the immune system is unable to see these parts (proteins) which, if effectively targeted, will cause an antibody reaction neutralizing several types of influenza virus,” commented Danielle Lingwood, co-author of the study.
The new vaccine redirects the immune system’s attention to this part of the protein, causing widely neutralizing antibodies that can potentially react to any strain of influenza.
The vaccine based on nanoparticles carries these “invisible” segments of hemagglutinine, which are distributed in it at a lower density, allowing antibodies to capture the proteins well.
When they tested a new mouse hike with the H1N1 hemagglutininin segment vaccine, this provoked the production of widely neutralizing antibodies. And in comparison with the usual vaccination against H1N1 strain 2009, the effect was better. The results obtained increase the probability that the new approach can be effective against any strain of influenza, the scientists concluded.