The study was published in the “Journal of Science Immunology”.
“The best immune defense takes place at the gate, protecting against viruses trying to get in,” said Iwasaki, a senior author of the study.
The mucous membranes have their own immune system that fights airborne or dietary pathogens. When exposed, these barrier tissues produce B cells, which in turn secrete immunoglobin A (IgA) antibodies. Unlike vaccines, which elicit a system-wide immune response, IgA antibodies act locally on mucosal surfaces in the nose, stomach, and lungs.
Although the protective role of IgA-producing cells was well established in the control of intestinal pathogens, Iwasaki’s laboratory wondered whether triggering an IgA response could also elicit a local immune response against respiratory viruses.
Working with researchers at Icahn School of Medicine in Mount Sinai, New York, they tested a protein-based vaccine designed to trigger an IgA immune response by giving it to mice by injection, as is usually done with systemic immunizations and also intranasally. . They then exposed the mice to several strains of influenza virus. They found that mice that had received the intranasal vaccine were much better protected against respiratory influenza than those that received injections. Nasal vaccines, but not vaccines, also induced antibodies that protected animals from several influenza strains, not just the strain against which the vaccine was intended to protect.
The Yale team is currently testing nasal vaccine strains against COVID strains in animal models.
“Although both vaccine injections and nasal vaccines increased antibody levels in the blood of mice, only the nasal vaccine allowed IgA to be secreted into the lungs, where the respiratory viruses must settle to infect the host,” Iwasaki said.
If nasal vaccines prove to be safe and effective in humans, Iwasaki envisions them being used in conjunction with existing vaccines and booster vaccines that work throughout the system to strengthen the immune system at the source of the infection.
Other first authors of the study are Ji Eun Oh, Eric Song, and Miyu Moriyama, all about Yale.
Source: ANI
Source: The Nordic Page