Scientists are on the verge of a ‘holy grail’ universal nasal vaccine for deadly viruses, bacteria and allergies… no needles necessary

Scientists say they are closing in on a ‘holy grail’ vaccine that could protect against coughs, colds, bacterial lung infections and even allergies, all in one annual nasal spray.

For decades, researchers have been trying to develop a universal vaccine against respiratory virus families by targeting a part of the pathogens that rarely mutates.

But now, researchers at Stanford University say they could protect against multiple pathogens at once using a nasal spray that mimics the signals released by immune cells, priming the immune system to immediately attack any invaders.

Mice given the spray had 700 times less virus in their lungs after being exposed to Covid and the bacteria behind pneumonia and strep throat than those who did not receive the spray, the scientists found.

Vaccinated mice also mounted an immune response in just three days, compared to around two weeks in unvaccinated rodents, and had immunity for three months.

The research is still in the early stages and has not been tested in humans, but scientists say they now hope to begin human trials.

Dr Bali Pulendran, the immunologist who led the study, said that, in a best-case scenario, it is likely still five to seven years away from being available to humans.

He said: ‘Imagine getting a nasal spray in the fall months that protects you from all respiratory viruses including Covid, flu, respiratory syncytial virus and the common cold, as well as bacterial pneumonia and early spring allergens.

‘That would transform medical practice.’

Scientists not involved in the study said it was ‘really exciting’ and could represent a ‘major step forward’ toward a new vaccine against respiratory diseases for humans. 

Dr Daniela Ferreira, a vaccinologist at the University of Oxford, in the UK, who was not involved in the research, said: ‘This is a really exciting piece of research that could change how we protect people from common coughs, colds and other respiratory infections.

‘If this strategy proves safe and effective in people… it could mark a major step forward, offering broader and more durable protection against the everyday infections that place such a heavy burden on individuals and health services alike.’

Dr Brendan Wren, a microbiologist at the London School of Hygiene and Tropical Medicine, who was also not involved in the research, added: ‘The study claiming a “universal respiratory vaccine” sounds too good to be true, but the researchers may have hit on a new concept for vaccination.’

The scientists hope their spray could lead to people only receiving one shot for winter viruses like Covid, the flu and pneumonia, but warn it would likely need to be repeated annually.

About 120 million doses of the flu vaccine are administered in the US every year, while 58 million Covid boosters are administered. Since the RSV vaccine was approved in 2023 as a one-time shot for adults over 60, nearly 13 million have received the injection.

It was not clear whether the mice suffered from any side effects due to the vaccine.

In the study, published in the journal Science, scientists administered drops of their new vaccine into the noses of mice.

Dubbed GLA-3M-052-LS+OVA, it mimicked the signals sent by T cells, a type of white blood cell that helps fight pathogens, that recruited other nearby white blood cells to the area, turning ‘on’ the immune system.

It also included a harmless antigen, an egg protein called ovalbumin, or OVA, which recruited more T cells to the area, causing the response to last for weeks to months.

It differs from traditional vaccines, which use a specific antigen, or part of a virus, to trigger an immune response. But the scientists said their shot led to a ‘double whammy’ of protection.

It triggered high immune cell activity, making it difficult for a pathogen to trigger an infection, while those that died were met with a near-immediate response. 

In the first round of the experiment, mice exposed to Covid and other coronaviruses that received three doses of the vaccine lost little weight, all survived, and their lungs were found to be virtually clear of the virus.

For comparison, mice that were not vaccinated but exposed to the viruses suffered from dramatic weight loss, several died, and their lungs were inflamed and full of virus. It was not clear how many of the mice died.

After these results, the researchers also exposed vaccinated mice to two bacteria that cause lung infections: Staphylococcus aureus, which causes strep throat, and Acinetobacter baumanii, which causes pneumonia. Vaccinated mice were also found to be protected against infection.

Next, the vaccinated mice were also exposed to a protein from house dust mites, a common trigger for allergic asthma, and were also found to be protected.

Dr Pulendran added: ‘The lung immune system is so ready and so alert that it can launch the typical adaptive responses—virus-specific T cells and antibodies—in as little as three days, which is an extraordinarily short length of time.

‘Normally, in an unvaccinated mouse, it takes two weeks.’

Now, the researchers are hoping to test their nasal spray in humans in a Phase I safety trial, which tests whether something is safe to use in humans. 

Researchers from Emory University School of Medicine, the University of North Carolina at Chapel Hill, Utah State University and the University of Arizona contributed to the work.