Stanford Researchers Develop Groundbreaking Universal Nasal Spray Vaccine

A single nasal spray could soon provide simultaneous protection against multiple infectious diseases, marking a significant breakthrough in vaccine development. Stanford Medicine researchers have developed a novel vaccine administered through a nasal spray that could potentially protect against COVID-19, influenza, pneumonia, and other respiratory conditions at once.

According to researchers, the intranasal vaccine provides “broad protection in the lungs for several months,” representing the closest science has come to creating a universal vaccine that protects against respiratory viruses, bacteria, and allergens simultaneously.

The findings, published in the journal Science, detail a preclinical study conducted on mice. The animals received the vaccine as a nasal drop, with some receiving multiple doses a week apart. When later exposed to respiratory viruses, the vaccinated mice demonstrated protection that lasted at least three months, while unvaccinated mice experienced dramatic weight loss, lung inflammation, and death. All vaccinated mice survived with clear lungs.

“By reprogramming the innate immune cells that act within hours of infection, the vaccine prepares the lungs to fight off many different respiratory viruses, even new ones,” said senior study author Bali Pulendran, PhD, a professor of microbiology and immunology at Stanford.

The vaccine’s protective effects extended beyond just common viruses. Vaccinated mice were protected against SARS-CoV-2 and other coronaviruses, as well as hospital-acquired infections like Staphylococcus aureus and Acinetobacter baumannii. Protection was even observed against house dust mites, a common allergen.

Unlike conventional vaccines that target specific pathogens, this universal approach trains the immune system in the lungs to provide broad protection. This suggests that the immune system can be conditioned to mount a more generalized antiviral defense mechanism in the respiratory tract.

“Imagine getting a nasal spray in the fall months that protects you from all respiratory viruses, including COVID-19, influenza, respiratory syncytial virus and the common cold, as well as bacterial pneumonia and early spring allergens,” Pulendran explained. “That would transform medical practice.”

If successfully translated to humans, this innovation could replace the need for multiple seasonal vaccinations, offering comprehensive protection with a single administration. It could also serve as a critical tool in preparing for future pandemic threats.

However, researchers emphasize important limitations to the current study. As a preclinical trial conducted on animal models, additional research is needed before any human applications can be considered. Pulendran described the study as “an important proof of concept rather than a finished human vaccine.”

“While the results are encouraging, additional studies are needed to determine safety, optimal dosing and effectiveness in people,” he added. “Our goal is not to replace current vaccines, but to complement them by developing strategies that could provide an added layer of protection against a wide range of respiratory threats, including future pandemics.”

The scientific team cautions that this research should not change current medical advice. The public should continue relying on approved vaccines and following public health guidance while development continues.

Dr. Robert H. Hopkins, Jr., medical director of the National Foundation for Infectious Diseases, who was not involved in the study, confirmed longstanding interest in universal vaccine development but urged caution in interpreting the results.

“This process is a fascinating concept, and the study is very interesting, but many additional steps need to be completed successfully and safely before this could be considered in humans,” Hopkins said. “The immune responses in mice are not identical to those in humans.”

With sufficient funding, researchers predict that human trials could begin soon, with potential availability in five to seven years. The study received funding from the National Institutes of Health, the Violetta L. Horton Professor endowment, the Soffer Fund endowment, and Open Philanthropy.