A new nasal vaccine could not only protect against whooping cough, but also significantly reduce the spread of the bacteria responsible for the disease, the epidemic of which continues in France.
- Unlike current vaccines, which are effective in preventing symptoms but incapable of preventing transmission, this new vaccine combines classic antigens with an innovative adjuvant, T-vant.
- The latter stimulates a local immune response in the respiratory tract, a key area for blocking bacterial colonization.
- Tested on mice, the vaccine eliminated the bacteria from the respiratory tract, where it usually spreads. Safe and promising, it could help eliminate whooping cough, according to researchers.
The whooping cough epidemic is experiencing its dynamics this year in France “the most important in at least 25 years”, according to the Pasteur Institute. An innovative nasal vaccine developed by Tulane University in the United States, currently facing a similar increase in cases, could revolutionize the fight against this highly contagious respiratory disease. An advance which promises not only to protect individuals, but also and above all to prevent the spread of the responsible bacteria, Bordetella pertussis.
A nasal vaccine that blocks bacterial colonization
Current pertussis vaccines, while effective in preventing symptoms, do not block the presence of the bacteria in the upper respiratory tract. Therefore, even vaccinated people can spread the disease. This limit is particularly concerning at a time when cases of whooping cough are increasing, with a five-fold increase reported by the Centers for Disease Control and Prevention (CDC) in the United States in one year.
The new vaccine combines traditional pertussis antigens with an innovative adjuvant, T-vant. The latter stimulates a local immune response in the respiratory tract, a key area for blocking bacterial colonization.
The tests, published in the journal npj Vaccinesshowed promising results in mice. Three weeks after infection, rodents vaccinated nasally with the T-vant vaccine no longer showed any trace of the bacteria in their lungs or in their nasopharynx, where the bacteria usually settles. Conversely, those who received the traditional vaccine by intramuscular injection retained bacteria in their upper respiratory tract.
No damage to lung tissue
Importantly, T-vant, derived from bacterial membrane vesicles, activates mucosal-specific immune cells without causing damage to lung tissue, ensuring the safety of the vaccine.
The researchers believe that this new approach could “significantly reduce community transmission” whooping cough. “These results show the importance of vaccines capable of stopping the spread of the bacteria among populations, beyond just individual protection”they emphasize in a press release.
With nearly 24 million annual cases worldwide, whooping cough particularly affects infants and immunocompromised people. If this nasal vaccine proves effective in humans, it could lay the foundations for eliminating the disease in the long term.
