Does the meningococcal vaccine also protect against gonorrhea?

iStock_000015704019XSmallDoes the meningococcal vaccine also protect against gonorrhea?

According to the World Health Organization, about 78 million new cases of gonorrhea are reported each year. An infection caused by Neisseria gonorrhoeae becomes very hard to treat. Increasing incidence of sexually transmitted diseases and resistance to common antibiotics force scientists to search for new treatments and prevention methods. So far, there is no commercially available vaccine againts N. gonorrhoeae , but recent research from New Zealand can change that. The scientists reported, that B-MeNZB® meningococcal vaccine used in 2004-2008 can prevent of gonorrhea. The results of the study were published in Lancet.

Gonorrhea is sexually transmitted disease (STD) caused by Gram-negative bacteria N. gonorrhoeae. Currently, gonorrhea is considered to be one of the most common STD in the world, following chlamydia infection. According to the World Health Organization (WHO), 357 million new cases of STD were reported in 2012, including 78 million cases of gonorrhea among people aged 15-49. Infection can lead to a serious medical complications known as disseminated gonococcal infection (DGI), an ectopic pregnancy or infertility of both sexes. Gonorrhea seems to be a serious health problem, because of the increasing frequency of casual sexual contacts and increasing resistance of the pathogen to available antibiotics. Furthermore, it is often asymptomatic or prodromal in women, what promotes further transmission of the microorganism in the population. Considering all of these, there is strong need to find alternative prevention methods to reduce infection spreading. Unfortunately, experimental studies of developed vaccines did not show their effectiveness so far.
Recent study published in Lancet by scientists from University of Auckland in New Zealand points a new direction in N. gonorrhoeae prevention by use of the meningococcal vaccine. Researches led by Dr. Helen Petousis-Harris evaluated the efficacy of group B (MeNZB®) meningococcal vaccine in individuals (aged 15-30 years). The Neisseria meningitidis serogroup B protein vaccine – MeNZB® was developed in Norway and it belongs to subunit vaccines. Vaccine antigens are the outer membrane vesicles of the N. meningitidis strain B group NZ98 / 254 (MeNZB antigen). MeNZB® is currently not registered and it was only developed to reduce meningococcal epidemic in New Zealand. The vaccine was administered to young people exposed to meningitidis type B and given in the years 2004 – 2008. It was short-term preventative measure and it was not associated with greater hope. However, a retrospective study by Petousis-Harris H. et al. showed that vaccinated group has reduced a risk of contracting gonorrhoea. Vaccinated people were less likely to be infected by N. gonorrhoeae in comparison to control group. Estimated efficacy of the vaccine was 31% (36% for women and 25% for men – gender differences were not statistically significant). The mechanism of immune response remains unknown, but studies provide evidence that vaccine antigen of N. meningitidis can give a cross-reaction with antigens of N. gonorrhoeae. This indicates, that we are dealing with the antigens affinity of Neisseria species. The results obtained by the researchers do not indicate a very good vaccine efficacy against gonorrhea, but it should be point out, that maintaining the immunity at a constant level can significantly reduce the incidence of disease over the next 15 years.

Authors: Małgorzata Kozioł, Agnieszka Sikora

Source:
Petousis-Harris H., Paynter J., Morgan J., Saxton P., McArdle B., Goodyear-Smith F., Black S.: Effectiveness of a group B outer membrane vesicle meningococcal vaccine against gonorrhoea in New Zealand: a retrospective case-control study. The Lancet 2017; acceass online: http://dx.doi.org/10.1016/S0140-6736(17)31449-6
WHO GUIDELINES FOR THE Treatment of Neisseria gonorrhoeae. WHO 2016; access online: http://apps.who.int/iris/bitstream/10665/246114/1/9789241549691-eng.pdf?ua=1

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