When 17-year-old Marcus got his meningococcal B shots at school, he was just following the rules. He didn't know the vaccine might protect him from something else entirely.
New research from Australia's Northern Territory suggests that young people who received two doses of the meningococcal B vaccine had a 38% lower risk of catching gonorrhea, a sexually transmitted infection that can lead to infertility if left untreated.
The study was led by Adelaide University in partnership with NT Health. Researchers looked at data from 30,650 adolescents and young people ages 14 to 22 across the Northern Territory and Ngaanyatjarra Lands in Western Australia. They found that those who got two doses of the 4CMenB vaccine were significantly less likely to contract gonorrhea than those who did not.
So how could one vaccine help prevent two completely different diseases? Researchers believe the answer lies in the bacteria themselves. The germs that cause meningococcal disease and gonorrhea are closely related, sort of like distant cousins. When the vaccine trains the immune system to recognize meningococcal bacteria, it also seems to help the body spot and fight gonorrhea bacteria more effectively.
"This study adds to growing evidence that the MenB vaccine may offer modest protection against gonorrhea when provided to young people, in addition to its established role in preventing invasive meningococcal B disease," said Professor Helen Marshall of Adelaide University, the study's principal investigator.
The findings are especially significant because gonorrhea cases in Australia have doubled over the past 10 years. The infection is also becoming harder to treat as drug-resistant strains spread around the country.
"These are real-world findings from a high-burden setting for both invasive meningococcal disease and gonorrhea," said James Ward, co-investigator and director of the University of Queensland Poche Center for Indigenous Health. "The rollout of the vaccine should now be another tool in the toolbox to reduce unacceptably high rates of both invasive meningococcal disease and gonorrhea."
The Northern Territory has already taken notice. A funded MenB vaccination program for infants and Year 9 students was introduced there last year, partly based on these promising results. Researchers say this approach could eventually be adopted more widely if the benefits hold up over time.
The team, led by Professor Marshall and Mr. Ward through the NHMRC Center of Research Excellence in Neisseria Disease Control, will continue studying the vaccine's long-term effects on both gonorrhea and meningococcal disease. While more work remains to be done, the early results suggest one needle prick might someday protect young people from more than one serious illness.