SARS-Cov-2 subtypes like delta and omicron have prompted scientists to reevaluate the efficacy of previously developed COVID-19 immunizations and booster shots.
Yale’s Akiko Iwasaki, the Waldemar Von Zedtwitz Professor of Immunobiology, believes that a new reaction to the fast-changing virus may be located right at the gateway to our lungs. New research shows that intranasal vaccination gives broad-based protection against heterologous respiratory viruses in mice, whereas so-called systemic immunization, which employs an injection to elicit body-wide protection, does not..
Science Immunology, a peer-reviewed magazine, published their findings on Dec. 10.
According to research senior author Iwasaki, “the finest immune defense happens at the gate, protecting against viruses seeking to enter.
Airborne or foodborne infections can be fought off by the mucous membrane’s own immune defense system Immunoglobin A (IgA) antibodies are secreted by B cells when these tissues are challenged. IgA antibodies, on the other hand, target mucosal surfaces located in the nose, stomach, and lungs, rather than the entire body.
It had long been known that IgA-producing cells might guard against intestinal pathogens, but Iwasaki’s research team wanted to see if initiating an IgA response could also cause a localized immune response against respiratory viruses.
Using mice and researchers from the Icahn School of Medicine at Mount Sinai in New York, they tested a protein-based vaccination designed to kick-start an IgA immune response. The vaccine was administered intravenously and intramuscularly to the animals. They then infected mice with influenza viruses of several strains. They discovered that intranasally administered vaccination provided superior protection against respiratory influenza in mice compared to injections. Additionally, the nasal vaccines generated antibodies that protected the animals against a number of flu strains in addition to the specific strain against which the vaccine was intended.
Nasal vaccine strains are currently being tested against COVID strains in animal models by the Yale researchers.
However, IgA release into lungs was only facilitated by nasal vaccines despite both vaccine injections and injections increasing antibody levels in mice’s blood, according to Iwasaki.
Iwasaki anticipates the nasal vaccines being used in concert with current vaccines and boosters that act across the body to provide immune system reinforcements at the point of infection if they show safe and effective in humans.
