A nasal spray on rats boosted lung immunity against viruses, bacteria and allergens. The next goal is to create a truly universal vaccine, but that’s still a long way off…
Imagine a single vaccine that protects against the flu, COVID-19, lung-invading bacteria, and seasonal allergens, all at once.
Scientists recently developed a nasal spray to protect against multiple respiratory diseases, including seasonal flu and COVID-19, which they have so far tested on mice over a three-month period.
As detailed by , although it does not stimulate the immune system in the same way as classic vaccines, researchers call the promising invention a “universal respiratory vaccine”,
So how far are we from a truly universal vaccine that can target all respiratory pathogens?
Experts told the same magazine that although the new research, whose results were released in February Science be interesting, truly universal vaccine is still years away.
Flu and COVID-19 vaccines need to be updated every year to remain protective because flu viruses and coronaviruses are constantly mutating.
“As they circulate, viruses mutate in ways big and small,” said the Alfredo Mena Loramedical director of infection control at Saint Anthony Hospital in Chicago, Illinois.
This push for universal vaccines accelerated after the COVID-19 pandemic exposed how vulnerable the world is to new respiratory pathogens, as well as how quickly existing vaccines become obsolete in the face of mutations.
Since then, researchers have focused on developing vaccines that can last longer and protect against more variantspotentially reducing the need for frequent updates to vaccine formulas.
Universal vaccines in development
Many universal vaccines in development target parts of viruses that change very little between strains.
For example, in the case of influenza, researchers are targeting the protein hemaglutinina that protrudes from the viral surface, but they are focusing on the “stem” rather than the “head” of this protein, because the stem mutates more slowly.
A FluMos-v2 of the National Institutes of Health (NIH), which targets the hemagglutinin of six strains of influenza, recently completed early-stage human clinical trials and generated encouraging immune responses.
An intranasal flu vaccine is already in clinical trials at a more advanced stage – recalls Live Science. It uses whole inactivated viruses to stimulate the body to produce antibodies, which block infection, and T cells, which attack infected cells.
This approach could provide broad protection against multiple flu strains and potentially block transmission — something current flu vaccines do not do.
Other scientists are working on pancoronavirus vaccines to protect against current and future coronaviruses, while others explore vaccines designed with artificial intelligence.
These are constructed using computational tools to identify regions of viral proteins that mutate very slowly and appear in many viruses.
Hope is in the “spray”
However, the recent nasal spray study is unique insofar as it aims to protect against viruses, bacteria and allergensrather than just one family of pathogens.
Unlike traditional vaccines, the experimental nasal spray does not teach the immune system to recognize proteins specific to a particular antigen, researchers reported in the new study.
Instead, stimulates the first line of defense of the immune system, known as the innate immune system.
This acts as an early warning system in the lungs, ready to quickly detect and respond to a wide range of pathogens, even those the body has never encountered before.
“These cells [pulmonares] They are the first to detect the infection and help determine how the immune response develops. And we have learned over the last decade that cells of the innate immune system can also be ‘trained’ to respond more quickly and more effectively to future threats”, explained the study leader, Bali Pulendrana pathologist at Stanford University, told Live Science.
The concept is based on research with the Bacillus Calmette-Guérin (BCG) vaccine, which prevents tuberculosis.
In 2023, Pulendran and colleagues found that mice given BCG showed T cells traveling to the lungs. There, they released signals that kept innate immune cells active in the lungs for months, protecting mice against both COVID-19 and flu.
This new nasal spray activates similar immune protection. Combines two adjuvantsor substances that trigger an immune response, to activate T cells and attract them to the lungs.
These T cells send chemical signals that mimic natural cues of infection, keeping the innate cells in the lungs activated and on high alert. If a pathogen enters the lungs, the innate immune cells will be prepared to stop the infection from the beginning.
The team is now preparing early-stage human trials.
