Daijiworld Media Network - Washington
Washington, Feb 22: Researchers at Stanford University have developed and tested a single nasal spray vaccine in animals that they say could offer protection against a wide range of respiratory viruses and bacteria, including flu, common cold viruses and certain bacterial lung infections.
The study, published in the journal Science, describes what the team calls a “universal vaccine” that works differently from conventional immunisation strategies.
Unlike traditional vaccines — pioneered in the late 18th century by Edward Jenner — which train the immune system to target a specific pathogen, the new approach mimics how immune cells communicate. Instead of priming the body against a single infection, it leaves key immune cells in the lungs on heightened alert.
Administered as a nasal spray, the vaccine activates white blood cells known as macrophages, placing them on what researchers described as “amber alert”, ready to respond rapidly to invading pathogens.
In animal experiments, this heightened readiness lasted around three months and resulted in a 100-to-1,000-fold reduction in viruses entering the body through the lungs. The vaccine also showed protection against bacterial species including Staphylococcus aureus and Acinetobacter baumannii.
Prof Bali Pulendran, professor of microbiology and immunology at Stanford, said the vaccine triggered a broad protective response not only against influenza, Covid and common cold viruses, but also against multiple bacteria and even allergens.
“The principle by which this vaccine works is a radical departure from the principle by which all vaccines have worked so far,” he said.
The researchers also observed that the immune modulation appeared to reduce reactions to house dust mite allergens, which are linked to allergic asthma.
Independent experts have welcomed the findings while urging caution. Prof Daniela Ferreira of the University of Oxford described the study as “really exciting” and said it could potentially change how respiratory infections are prevented if confirmed in human trials.
However, several questions remain. It is unclear whether the same immune effect can be achieved in humans or how long the lungs would remain in this heightened state. Scientists also noted differences between mouse and human immune systems, particularly given humans’ lifetime exposure to infections.
Future trials are expected to involve vaccinating volunteers and then deliberately exposing them to infections under controlled conditions to assess protection levels.
Prof Jonathan Ball of the Liverpool School of Tropical Medicine cautioned that while the concept is promising, maintaining the immune system on high alert could risk unintended inflammatory or autoimmune side effects.
The research team said the vaccine is not intended to replace existing targeted vaccines but could complement them — especially in the early stages of a pandemic before a pathogen-specific vaccine is developed.
They also suggested that a seasonal nasal spray could potentially provide broad protection during winter months when multiple respiratory viruses circulate widely.