In a major step forward, researchers at Tulane University have created a nasal vaccine that could greatly reduce the spread of whooping cough, a very common lung disease caused by Bordetella pertussis. The number of whooping cough cases in the US is five times higher than a year ago, according to the Centers for Disease Control and Prevention (CDC). This new vaccine is an important step toward stopping the disease from spreading.

The current pertussis vaccines work to stop serious illness, but they are not effective at stopping the bugs from spreading. People who have been vaccinated can still have the germs in their upper respiratory tract and unknowingly give the disease to others, especially babies and people whose immune systems aren't working as well.

Tulane experts developed an innovative nasal vaccine to fill this gap. The vaccine directly targets the respiratory tract by combining traditional pertussis antigens with a new type of adjuvant called T-vant. This boosts the immune reaction where the bacteria first settle.

A new study in the journal NPJ Vaccines showed that the vaccine worked in mice. Three weeks after getting infected, mice that were given the T-vant vaccine through the nose had no Bordetella pertussis in their lungs or nasopharynx (the area behind the nose). People who got the traditional intramuscular vaccine, on the other hand, still had the bacteria in their upper respiratory system. This shows that the nasal vaccine is better at stopping colonization and transmission.

"We hope to improve existing vaccines and stop the spread of whooping cough in communities by making a vaccine that can not only protect individuals but also stop transmission," said Dr. Lisa Morici, who led the study and is a professor of microbiology and immunology at Tulane University School of Medicine.

It is the T-vant adjuvant that makes the vaccine work. T-vant comes from bacterial outer membrane vesicles and triggers a mucosal immune reaction. This activates key immune cells in the respiratory tract, preventing the bacteria from colonizing.  Importantly, the study found that the vaccine did not hurt lung cells, which shows that it is safe.

Dr. James McLachlan, co-author and associate professor at Tulane University, said, "These results make it clear that we need better vaccines that can do more than just protect individuals." "We need vaccines that can stop the bacteria from spreading in communities, and this new approach is a good step in the right direction."

Whooping cough is still a major public health problem around the world. It impacts approximately 24 million individuals annually and results in numerous infant deaths. The rise in cases in the U.S. shows how badly we need a vaccine that can stop both getting sick and spreading it.

If human trials replicate the positive results from animal studies, this nasal vaccine could effectively eradicate whooping cough. Going after the source of the disease not only protects people but also makes the community's defenses stronger against it.

Dr. Morici was optimistic about the vaccine's chances: "A vaccine that can successfully prevent infection and transmission of whooping cough in humans could set the stage for eradicating the disease completely."

In this new way, Tulane University's nasal vaccine gives us hope to stop a rising public health threat and protect people who are more likely to get sick.