Scientists at the University of Pittsburgh School of Medicine in the United States have discovered a class of previously unrecognized antibodies in human blood. This immune system protein seems to be able to neutralize various forms of influenza virus. The latest research or development is crucial for targeting seasonal viruses and providing a wide range of protective vaccines. The relevant paper was published in the journal PLoS Biology on December 21st. The research team explained that the influenza vaccine stimulates the immune system to produce antibodies. This antibody can bind to the hemagglutinin virus protein outside the invading influenza virus, preventing it from entering human cells. Different antibodies bind to different parts of hemagglutinin in different ways, but hemagglutinin itself evolves over time, producing new strains of influenza that can evade old antibodies. Therefore, pharmaceutical manufacturers provide new influenza vaccines every year based on predictions of the most important strains. In view of this, researchers are developing influenza vaccines that can simultaneously resist multiple strains, with a focus on antibodies that can simultaneously resist H1 and H3 influenza subtypes. These two subtypes contain multiple strains and are the cause of widespread infection in people. In the latest study, Holly Simmons team discovered a small change in some H1 strains in the sequence of hemagglutinin building blocks -133a insertion. Research has shown that certain antibodies that can neutralize H3 can also neutralize H1. But if the above minor changes occur in hemagglutinin, the antibody cannot neutralize H1. In a series of experiments conducted on patient blood samples, the team discovered a new class of antibodies. Experiments have shown that regardless of whether 133a insertion occurs, this antibody can neutralize certain H3 and H1 strains. And the unique molecular characteristics make these antibodies different from other antibodies that can neutralize H1 and H3 strains. The research team pointed out that people need to get vaccinated against influenza virus once a year to keep up with the continuous evolution of the virus. The latest research suggests that humans may develop powerful antibody responses to neutralize different H1N1 and H3N2 viruses, opening up new avenues for designing better vaccines against influenza viruses. (Liu Xia) (Le Xin She)