Gonorrhea is a sexually transmitted disease that continues to advance, since 12,359 new cases were registered in Spain in 2019, and between 2013 and 2019 the annual increase in this infection was 25.2%, according to data from the Carlos III Health Institute . Worldwide, in 2020 alone, more than 80 million cases were diagnosed and a significant percentage of those affected presented resistance to the treatments administered.
There is currently no vaccine available to prevent gonorrhea, but three studies that have been published in the scientific journal The Lancet Infectious Diseases (one carried out in Atlanta, another in Australia and a third in Great Britain) indicate that the The meningococcal B vaccine could be useful in protecting young people and men who have sex with men and are at higher risk of infection from this infection.
Studies have shown gonococcal disease prevention rates that range between 33% and 40%, and although these percentages are not very high, they could significantly contribute to slowing down the progression of the infection. The cross-protection revealed by these studies is due to the fact that the microorganisms that cause both diseases have certain similarities: they are bacteria of the Neisseria genus (Neisseria meningitidis serogroup B and Neisseria gonorrhoeae) and, therefore, share part of their genetic material.
The administration of two doses of the meningococcal B vaccine provided 40% protection against gonorrhea, while the administration of one dose decreased this percentage to 26%.
The 4CMenB vaccine (Bexero) is based on “protein subcapsular antigens. In previous studies it had already been seen that these antigens were not only present in serogroups other than B, but also in other species of Neisseria, specifically in Neisseria gonorrhoeae”, explained Federico Martinón, member of the Vaccine Advisory Committee of the World Organization of Health and head of Pediatrics at the University Clinical Hospital of Santiago de Compostela, in statements to Diario Médico.
Two doses of the vaccine increased protection against gonorrhea
The first of the aforementioned studies analyzed this relationship in an observational manner in young Americans between 16 and 23 years of age. The researchers identified gonorrhea cases in a group of 110,000 people, of whom 7,692 had received one (52%) or two doses (47%) of the 4CMenB vaccine. They found 18,099 cases of gonorrhea and 24,731 co-infections with chlamydia. The results showed that the administration of two doses provided 40% protection against gonorrhea, while the administration of one dose decreased this percentage to 26%.
The second study, also of an observational nature, has been carried out in South Australia, where 53,000 adolescents have received at least one dose of the meningitis B vaccine. The researchers estimated that vaccination with two doses provided protection from the 33% against gonorrhea.
And the third study, which used an estimation model, found that vaccinating men who have sex with men against meningococcus B would prevent 110,000 cases of gonorrhea and save eight million pounds over a decade in England.
Although these are preliminary studies, “the data they provide are important,” says Miguel Górgolas, head of the Infectious Diseases service at the Fundación Jiménez Díaz Hospital in Madrid, who adds: “To draw definitive conclusions, we have to wait for clinical trials in the III, but the available evidence shows an interesting effect.”
The bacterium responsible for gonorrhea – Neisseria gonorrhoeae – is also becoming more resistant to treatments against gonococcal disease, so it is urgent to find new ways to prevent it. “Fortunately, in Spain, there are still not many cases of resistance, but in other countries they already have a significant problem with strains resistant to drugs such as ceftriaxone, an antibiotic that is administered parenterally and is the treatment of choice against gonorrhea. ”, highlights Gorgolas. “If it’s not stopped, there may come a time when the infection is very difficult to treat.”
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