As cases of whooping cough rise in the US, a new nasal vaccine developed by Tulane University may hold the key to reducing the spread of the highly contagious respiratory disease.

Current whooping cough vaccines are widely used and effective in preventing whooping cough, caused by Bordetella pertussis bacteria. However, vaccines fail to clear the bacteria from the upper respiratory tract, allowing even vaccinated people to spread the disease.

The new vaccine combines traditional pertussis antigens with an innovative adjuvant called T-vant, which stimulates the body’s immune response, particularly in the respiratory tract. In a study published in npj Vaccinesmice immunized intranasally with the new T-vant vaccine showed no signs of the bacteria in their lungs and nasopharynx – the upper throat area behind the nose – three weeks after infection. The bacteria remained predominant in the upper respiratory tract of mice that received the traditional intramuscular vaccine.

By developing a vaccine that can not only protect individuals, but also prevent transmission, we hope to improve existing vaccines and limit the spread of whooping cough in communities.”

Lisa Morici, lead study author, professor of microbiology and immunology, Tulane University School of Medicine

T-vant adjuvant is derived from bacterial outer membrane vesicles, tiny particles that naturally stimulate the immune system. The study found that the adjuvant encouraged a mucosal immune response, stimulating the activation of immune cells in the respiratory tract, essential for stopping the bacteria’s ability to colonize.

The study also found no adverse effects on lung tissue after immunization, highlighting the safety of the vaccine.

The findings are significant and come at a time when cases of whooping cough are on the rise. Recent data from the Centers for Disease Control and Prevention showed a fivefold increase in cases in the US over last year. The disease affects about 24 million people a year worldwide and primarily affects infants and those with weakened immune systems.

A vaccine that can successfully prevent infection and transmission of whooping cough in humans could lay the groundwork for eliminating the disease altogether, said James McLachlan, study co-author and associate professor of microbiology and immunology at Tulane School of Medicine.

“These findings underscore the need for improved vaccines that can do more than protect the individual,” McLachlan said. “We need vaccines that can effectively stop the spread of the bacteria within communities, and this new approach provides an encouraging step in that direction.”

T-vant was developed with support from the NIH Adjuvant De