The World Health Organization commented Friday on gonorrhea's increasing resistance to antibiotics, noting the STD now afflicts 78 million people each year, including patients whose cases "are untreatable by all known antibiotics." It's good timing, then, for what appears to be the first ever vaccine to protect against gonorrhea—apparently discovered by accident. A vaccine to protect against a form of meningitis known as meningococcal B was given to 90% of New Zealanders between 2004 and 2006 in response to an outbreak, reports CNN. Later, however, researchers noticed rates of gonorrhea—caused by a bacteria closely related to the one that causes meningococcal disease—had fallen along with those of meningococcal B.
With a closer look at 15,000 cases, researchers found the gonorrhea infection rate was 31% lower among people who'd received the single-component meningococcal B vaccine, known as MeNZB, than among those who weren't vaccinated. MeNZB is no longer in use, but updated version 4CMenB contains the same component and was later used in Quebec, Canada. Researchers say gonorrhea rates have also fallen among the vaccinated population there, STAT News reports. "This is the first time a vaccine has shown any protection against gonorrhea," the author of the study in the Lancet tells the BBC. She adds more research is needed since "the mechanism behind this immune response is unknown." (Could mouthwash prevent gonorrhea, too?)