As cases of whooping cough rise in the U.S., a new nasal vaccine developed by Tulane University may be the key to reducing the spread of this highly contagious respiratory disease.
Current pertussis vaccines are widely used and effective in preventing pertussis, caused by Bordetella pertussis bacteria. However, vaccines fail to eliminate 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 specifically 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 the lungs and nasopharynx (the upper area of the throat behind the nose) three weeks after infection. The bacteria remained prevalent in the upper respiratory tract of mice that received the traditional vaccine intramuscularly.
“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 pertussis in communities,” said study senior author Lisa Morici, professor of microbiology. and immunology at Tulane University School. of Medicine.
T-vant adjuvant is derived from bacterial outer membrane vesicles, small particles that naturally stimulate the immune system. The study found that the adjuvant fostered a mucosal immune response, stimulating the activation of immune cells in the respiratory tract critical to stopping the bacteria’s colonizing ability.
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 whooping cough cases are increasing. Recent data from the Centers for Disease Control and Prevention showed that cases in the United States increased fivefold from last year. The disease affects approximately 24 million people a year worldwide and primarily affects infants and people with weakened immune systems.
A vaccine that can successfully prevent pertussis infection and transmission in humans could lay the groundwork for eliminating the disease completely, said James McLachlan, co-author of the study 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 simply protect the individual,” McLachlan said. “We need vaccines that can effectively stop the spread of the bacteria within communities, and this new approach offers an encouraging step in that direction.”
T-vant was developed with support from the NIH Adjuvant Development Program.