Tests with mice and rabbits show that a pill can act as a vaccine that prevents bladder infections. For example, recurrent urinary tract infections can be treated preventively without the need for antibiotics.
A pill that dissolves under the tongue protects mice and rabbits from urinary tract infections. If this method also works in humans, it could reduce the use of antibiotics.
More than half of women contract a bladder infection at least once during their lifetime. About 5 to 10 percent of women suffer from three or more of these types of inflammation per year.
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To treat these recurring infections, the doctor sometimes prescribes daily antibiotics. This prevents the growth of the E. colibacteria, which is usually responsible for the inflammation.
However, long-term use of antibiotics can lead to bacteria becoming resistant to them. Also, antibiotics can disrupt healthy populations of gut bacteria, leading to gastrointestinal distress.
Training immune system
Biomedical scientists Sean Kelly and Joel Collier of Duke University have developed a vaccine as an alternative to antibiotics. This trains the immune system to recognize and fight cystitis-causing bacteria. To get the immune system to do so, the vaccine exposes it to three chains of amino acids usually found on the surface of the pathogens.
The vaccine is given as a tablet that dissolves under the tongue. This triggers an immune response in the urinary tract because the mucous membranes of the mouth and urinary tract are so similar.
Successful pill
The pill is very user-friendly. It can be stored at room temperature and patients can simply take it themselves. The fact that the vaccine does not need to be refrigerated can reduce the cost of delivery, says Kelly.
In mice, the vaccine was just as effective at preventing bladder infections as a high dose of antibiotics. The pill also did its job nicely in a follow-up experiment with rabbits. Because the vaccine specifically targets bacteria that cause cystitis, rather than other beneficial microbes, it did not disrupt the animals’ gut bacteria.
The team hopes these promising results pave the way for human clinical trials, Collier says. “We still have to do safety studies before we start clinical trials. We are looking for partners to implement it.’
Tongspray
The US team is not alone in developing an under-the-tongue vaccine against cystitis. The Spanish company Inmunotek also made such a vaccine, which has been given the name MV140. The MV140 vaccine is not a tablet, but a liquid that must be injected under the tongue twice a day for three to six months.
In a recent clinical study of 240 women with recurrent bladder infections, nearly 60 percent experienced no new inflammation in the nine months following administration of this vaccine. This was 25 percent among those who received a placebo.
For the American tablet, it is still unclear how long the protection lasts and whether booster tablets will be needed over time. But “even with boosters, it would be less disruptive than taking antibiotics,” says Kelly.