"Science Immunology" nasal vaccine is effective against virus mutation, but injection vaccine is not effective?

The focus of this study is to prevent influenza infection.

The two authors, led by Dr.

The results of the study also indicate that the immune response to the rapidly mutating SARS-CoV-2 virus may be at the door of our lungs

The author writes that the mucosal surface is continuously exposed to various types of pathogens and toxins.

When attacked, these barrier tissues produce B cells, which in turn secrete immunoglobulin A antibodies

Although the protective effects of IgA-producing cells against intestinal pathogens have been well established, Iwasaki's laboratory wanted to know whether triggering the IgA response might also produce local immune defense against respiratory viruses

Researchers at Yale University, in collaboration with researchers at the Icahn School of Medicine at Mount Sinai, tested a protein-based vaccine designed to initiate an IgA immune response by injection or intranasal injection into mice, just as they usually pass Systemic immunity does what it does

They found that compared with vaccinated animals, nasally vaccinated animals had better protection against respiratory flu

Iwasaki said that although both vaccine injections and nasal vaccines can increase the level of antibodies in the blood of mice, only nasal vaccines can secrete IgA into the lungs.

If the nasal vaccine proves to be safe and effective in humans, Iwasaki envisions using it in combination with current vaccines and boosters that work system-wide to strengthen the immune system at the source of infection

As the authors concluded, "In short, our data shows that after nasal immunization, IgA-producing cells are formed in the lungs and help prevent homologous and heterologous influenza virus infections