CALIFORNIA: Researchers reported an experimental nasal-spray vaccine that protected mice against multiple respiratory viruses, bacteria and an allergen for at least three months, according to a study published Feb. 19 in the journal Science. The intranasal formulation, called GLA-3M-052-LS+OVA, was tested in mice exposed to SARS-CoV-2 and other coronaviruses, as well as the bacteria Staphylococcus aureus and Acinetobacter baumannii. The study also evaluated responses to a protein from house dust mites, a common trigger for allergic asthma.
The vaccine was designed to stimulate immunity in the lungs by combining two immune-activating compounds that target toll-like receptors with a model antigen, ovalbumin, an egg protein often used in immunology research. Unlike conventional vaccines that focus on a specific pathogen component, the approach aimed to sustain a broader, local immune state in the airways. The authors described the formulation as a liposomal mixture that links early-acting innate defenses with longer-lived adaptive immune cells, including memory T cells, at the site where many respiratory infections begin.
In the mouse experiments described by the researchers, animals received the vaccine through the nose, with some given multiple doses one week apart. With three doses, the researchers reported protection against SARS-CoV-2 and other coronaviruses for at least three months. Unvaccinated mice developed severe illness, including pronounced weight loss, and many died, while vaccinated mice lost less weight and survived, the Stanford team said. The researchers also reported sharply lower viral levels in the lungs, including a 700-fold reduction during the prolonged innate response.
Broad protection in mouse tests
After observing protection against several coronaviruses, the researchers expanded the challenge tests to bacterial respiratory infections. The study reported that vaccinated mice were protected against S. aureus and A. baumannii for about three months. The team then tested whether the same approach affected allergic airway inflammation by exposing mice to a house dust mite protein. In those experiments, unvaccinated mice showed a strong Th2-type immune response and mucus buildup in the airways, while vaccinated mice showed reduced Th2 responses and maintained clearer airways, the researchers reported.
The study attributed the broad effects to immune changes that persisted in the lung after vaccination. The authors reported that ovalbumin-specific CD4 and CD8 memory T cells remained in the animals and “imprinted” alveolar macrophages, increasing antigen presentation and strengthening antiviral immunity. Following infection, vaccinated mice mounted faster pathogen-specific antibody and T cell responses, and the researchers observed ectopic lymphoid structures in the lungs, which can support rapid local immune activity. The paper framed the findings as evidence for a class of “universal vaccines” against diverse respiratory threats in mice.
Study team and what was measured
The research was led by Haibo Zhang at Stanford University School of Medicine, with Bali Pulendran as senior author, according to the paper’s author list. Co-authors included scientists affiliated with Emory University School of Medicine, the University of North Carolina at Chapel Hill, the University of Arizona, and the Access to Advanced Health Institute in Seattle. The study reported outcomes that included survival, weight change, lung inflammation and pathogen levels after exposure to viruses and bacteria, and immune markers associated with allergic airway responses after allergen challenge.
The authors emphasized that the work was conducted in mice and did not report testing in people. The formulation included ovalbumin as a model antigen rather than a pathogen-specific target, and the study’s “universal” description referred to breadth across the tested challenges rather than to all respiratory diseases. The paper reported durability of protection and immune changes over a period of at least three months in the mouse models used, and it described the immune signatures linked to that protection, including lung-resident memory T cells and altered function of alveolar macrophages – By Content Syndication Services.