Intranasal vaccine delivery offers numerous and clear advantages over traditional intramuscular vaccines that go beyond eliciting a robust immune response at a primary point of pathogen exposure.
By triggering systemic and mucosal immunity in the nose, lungs, and blood, these vaccines elicit rapid protection and a robust defense against respiratory pathogens. Intranasally administered vaccines can stimulate IgA secretion in the upper airway mucosa and effectively neutralize viruses and bacteria before they can establish infection. Furthermore, the establishment of resident memory B and T cells in the respiratory mucosa ensures a quicker and more potent response upon pathogen re-exposure, potentially blocking subsequent infection and preventing transmission.
One remarkable advantage of intranasal vaccines is that they lower virus shedding, thereby strengthening public health effects by minimizing the spread of pathogens within the community.
As a non-invasive alternative to intramuscular injection, intranasal vaccines are suitable for subjects of all ages. They may also help overcome vaccine hesitancy and needle phobia, enhancing vaccination coverage. Intranasal vaccines are easy to administer and eliminate the risk of needle accidents. This makes them ideal for low- and middle-income countries, where healthcare resources can be limited.
The advantages of intranasal vaccines are particularly attractive for globally distributed pathogens like SARS-CoV-2. Studies examining novel intranasal COVID-19 vaccines have shown strong and robust antibody-mediated and cell-mediated immunity. The vaccines can prevent virus replication and shedding, and thus, possibly limit virus transmission.
“The ideal vaccine against COVID-19 would be one that can block transmission of the virus. To achieve this, the vaccines should elicit a strong mucosal immune response at the site of infection. If the vaccine can prevent the virus from entering the cells and replicating at the early stages of infection, it could effectively halt the entire process of infection.”
Prof. Ed Lavelle
School of Immunology at Trinity College Dublin, Ireland
At Intravacc, we believe that intranasal vaccines represent a promising avenue in the fight against infectious diseases, offering a multitude of advantages for public health. Their innovative approach to immune protection and ease of administration could pave the way for a brighter, healthier future worldwide.