Universal Vaccine Shows Promise Against Respiratory Viruses, Bacteria & Allergies | Stanford Study

A universal vaccine offering broad protection against respiratory illnesses – from common colds to potentially pandemic-causing viruses – is moving closer to reality, thanks to groundbreaking research from Stanford Medicine. A new study, published in Science on February 19, 2026, details a novel vaccine formula tested in mice that demonstrates protection against a wide range of respiratory viruses, bacteria and even allergens.

Unlike traditional vaccines that target specific pathogens, this innovative approach focuses on bolstering the body’s innate immune system – the first line of defense against infection. The vaccine, administered intranasally (similar to a nasal spray), provides broad lung protection for several months. Researchers believe that, if successfully translated to humans, this vaccine could significantly reduce the burden of seasonal respiratory infections and offer a crucial defense against emerging pandemic threats.

Beyond Specificity: Harnessing the Power of the Innate Immune System

For over two centuries, vaccination has relied on the principle of specificity, training the immune system to recognize and fight off particular pathogens. However, the rapid mutation of viruses like SARS-CoV-2 has highlighted the limitations of this approach. The Stanford team’s research represents a paradigm shift, moving away from mimicking specific viruses and instead replicating the communication signals that immune cells use during a real infection.

The adaptive immune system, responsible for long-term immunity, typically takes time to develop a targeted response. The innate immune system, is activated within minutes of infection but is traditionally considered short-lived. Researchers have long recognized the innate immune system’s versatility, with its generalist cells – such as dendritic cells, neutrophils, and macrophages – capable of destroying a wide range of potential threats. “What’s remarkable about the innate system is that it can protect against a wide range of different microbes,” explains Bali Pulendran, PhD, a professor of microbiology and immunology at Stanford and the study’s senior author.

The study builds on previous research demonstrating that the Bacillus Calmette-Guérin (BCG) tuberculosis vaccine can offer cross-protection against other infections. Pulendran’s team discovered that the BCG vaccine’s prolonged effect was due to signals from T cells – a component of the adaptive immune system – maintaining the activation of innate immune cells for an extended period. “These T cells provided a crucial signal to maintain the activation of the innate system, which normally lasts a few days or a week, but in this case it could last three months,” Pulendran stated.

Mimicking Immune Signals for Broad Protection

The new vaccine, currently designated GLA-3M-052-LS+OVA, mimics these T cell signals, directly stimulating innate immune cells in the lungs. It also includes a harmless antigen, ovalbumin (OVA), an egg protein, to recruit T cells to the lungs and sustain the innate immune response for weeks or months. In the mouse study, a single drop of the vaccine administered intranasally, with some mice receiving multiple doses a week apart, proved remarkably effective.

Mice vaccinated with the formula were protected against SARS-CoV-2 and other coronaviruses, as well as common hospital-acquired bacterial infections like Staphylococcus aureus and Acinetobacter baumannii. Importantly, the vaccine also demonstrated efficacy against house dust mites, a common allergen, suppressing allergic reactions and keeping airways clear.

“I think what we have is a universal vaccine against various respiratory threats,” Pulendran declared. The vaccine appears to work on two fronts: reducing the viral load in the lungs by up to 700-fold through the prolonged innate immune response, and priming the adaptive immune system for a faster, more robust response to any virus that manages to evade the initial defense. “The lung immune system is so prepared and alert that it can activate typical adaptive responses…in just three days, an extraordinarily short time,” Pulendran explained. “Normally, in an unvaccinated mouse, it takes two weeks.”

Looking Ahead: Human Trials and Potential Impact

Researchers are optimistic about the potential for translating these findings to humans. The next steps involve Phase I safety trials, followed by larger trials to assess the vaccine’s efficacy in preventing infections. Pulendran estimates that, with sufficient funding, a universal respiratory vaccine could be available within five to seven years. Such a vaccine could not only simplify seasonal vaccination schedules but also provide a critical defense against future pandemics.

The study was funded by the National Institutes of Health, the Professor Violetta L. Horton Endowment, the Soffer Fund Endowment, and Open Philanthropy.