A new mouth-spray vaccine reportedly stops urinary tract infections (UTIs) from coming back again and again, as can happen in many people prone to the condition.
The pineapple-flavored vaccine, called Uromune, has so far been tested in one study without a placebo group and one completed gold-standard clinical trial. Both studies suggest that, for more than half of the participants, the vaccine helped ward off recurrent UTIs for months. It will need more testing to be fully approved but shows promise.
"Vaccines would be a game changer for a huge number of people who are, at the moment, stuck with long-term UTIs and there's nothing that can help them," Jennifer Rohn, a researcher who specializes in renal medicine at University College London and was not involved in the studies, told Live Science.
A new way to prevent UTIs?
UTIs can cause debilitating pain; abdominal cramping; and an urge to urinate when you don't need to. Approximately 50% of women will have a UTI at least once in their life; of those, 22% will experience recurrent infections.
Women are about 30 times more likely to get UTIs than men.
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Many patients who develop UTIs repeatedly are prescribed preventive antibiotics to help reduce their risk of future infections. Yet research shows that heavy reliance on antibiotics has led to the emergence of multidrug-resistant bacteria. Plus, antibiotics can wipe out helpful bacteria in the body along with the disease-causing kind.
UTI vaccines could offer an alternative approach, and Uromune is one such vaccine. The spray contains a mixture of the four bacteria most commonly responsible for recurrent UTIs: Escherichia coli, Klebsiella pneumoniae, Enterococcus faecalis and Proteus vulgaris.
"Together, they make up about 88% of urinary tract infections," Dr. Glenn Werneburg, a physician-scientist at the Cleveland Clinic who was not involved in the studies, told Live Science. For the vaccine, these bacteria are inactivated by heat so that the proteins on their surface are still intact and thus can be identified by the immune system.
The vaccine is sprayed under the tongue because exposing the base of the tongue, the tonsils and the roof of the mouth is thought to trigger a strong immune response in "mucosal" tissues. These include the lining of the urinary tract and bladder, Werneburg said.
Scientists first tested the vaccine in a U.K.-based trial of 75 female participants; there was no comparison group that didn't use the spray. In that study, 59% of the women who used the spray daily for three months had no subsequent UTIs for the following year. These participants had experienced three or more UTIs in the year prior to receiving the vaccine.
In a second phase of the study, the scientists followed up with nearly 40 of the original participants, and they also added 17 men to the trial. In that group they found that, for 48 of them, the vaccine was still very protective nine years after its initial administration. These participants had remained UTI-free over that period and had no adverse effects.
On average across the whole group, all the patients remained UTI-free for about 55 months, or about 4.5 years.
The findings of this study were presented at the European Association of Urology Congress in Paris on April 6. Uromune has also been tested in one gold-standard clinical trial with a placebo group. In that trial, 56% and 58% of women who used the spray for three and six months, respectively, remained free of UTIs for up to nine months, compared to only 25% of the placebo group.
"I'm excited about these findings because it's more evidence that this vaccine may be an excellent alternative for these patients," Werneburg said.
Next steps
Both the trials had limitations. For instance, the vaccine has only been tested for uncomplicated UTIs, meaning infections that don't involve catheters, fever, the kidneys or other complicating factors, for example.
"Some of the people who are most prone to infection are people with neurogenic lower urinary tract dysfunction and people with chronic indwelling catheters," Werneburg said. "I really look forward to trials that assess the vaccine's safety and efficacy in these populations."
Not everyone responded to the vaccine in these initial trials. But "given how complicated UTI is and how every patient has something different going on — different bugs, different immune systems — half of the people responding is actually really good," Rohn said.
One possible reason some patients did not respond could be that they were infected by types of bacteria not included in the vaccine. Bacteria can also hide from the immune system and antibiotics by sticking to the bladder wall and coating themselves with a slimy shield. Other UTI vaccines being tested in mice could potentially target these germs.
Uromune has not yet been approved by the Food and Drug Administration for any use in the U.S. However, currently, it's available for compassionate use in 26 countries, meaning it's available to people who aren't enrolled in a formal trial but who haven't responded to other treatments. Time will tell if it will earn full approval for UTI prevention.
This article is for informational purposes only and is not meant to offer medical advice.
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