In an effort to tackle the resurgence of whooping cough, researchers have unveiled a promising new vaccine that not only protects individuals from the disease but also curtails transmission. Despite the effectiveness of current pertussis vaccines in preventing whooping cough, caused by the Bordetella pertussis bacteria, they fall short in eliminating the bacteria from the upper respiratory tract. This allows vaccinated individuals to unknowingly spread the bacteria.
A study published in the journal npj Vaccines highlighted the potential of a new vaccine that blends traditional pertussis antigens with an innovative adjuvant, T-vant, known for enhancing immune response specifically in the respiratory tract. In experiments on mice, those immunized intranasally with the T-vant vaccine were free of the bacteria in both the lungs and nasopharynx—the area behind the nose—three weeks post-infection. In contrast, mice given the traditional vaccine intramuscularly continued to harbor the bacteria in their upper respiratory tracts.
"By developing a vaccine that can not only protect individuals but also prevent transmission, we hope to improve on existing vaccines and limit the spread of whooping cough in communities," said Lisa Morici, lead study author and a professor of microbiology and immunology at Tulane University School of Medicine.
Derived from bacterial outer membrane vesicles, T-vant naturally stimulates the immune system. The study revealed that this adjuvant promoted a mucosal immune response, crucial for activating immune cells in the respiratory tract to thwart bacterial colonization. Importantly, the study also noted that there were no adverse effects on lung tissue following the immunization, attesting to the vaccine's safety.
This research is particularly timely given the current surge in whooping cough cases. Recent statistics from the Centers for Disease Control and Prevention indicate a five-fold increase in U.S. cases compared to the previous year. Globally, the disease affects approximately 24 million people annually, predominantly impacting infants and those with weakened immune systems.
James McLachlan, a co-author of the study and associate professor of microbiology and immunology at Tulane School of Medicine, emphasized the broader implications of the findings. "These findings underscore the need for enhanced vaccines that can do more than just protect the individual," he stated. "We need vaccines that can effectively stop the bacteria from spreading within communities, and this new approach offers an encouraging step in that direction."
The development of T-vant was supported by the NIH Adjuvant Development Program, signaling hope for a vaccine that could pave the way for the eventual eradication of whooping cough.
