A vaccine against meningococcus also protects against gonorrhea

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Vaccine against meningococcus also protects:

The antibioticness of worried gonococcus. Nevertheless, A surprising discovery: the vaccine against meningococcus B also protects against gonorrhea thanks to shared antigens. Therefore, The United Kingdom is testing this preventive strategy.

Gonorrhea remains a major global public health issue. Meanwhile, According to the WHO, this sexually transmitted infection affected 82.4 million new people in 2020 in the 15-49 year old age group. Therefore, an annual incidence rate of 19 ‰ among women and 23 ‰ in men. Similarly, African and Western Pacific regions concentrate the majority of cases (1).

Resistance to antimicrobials in Neisseria gonorrhoeae appeared from the introduction of the first antimicrobials. Nevertheless, has continued to expand in the past 80 years. Consequently, It now affects many therapeutic classes: tetracyclines, macrolides (azithromycin), sulfonmide-trimehoprime associations and, more recently, Quinolones. Meanwhile, The ultra -resistant strains. Similarly, both resistant to the current reference treatment (CEFTRIAXONE) and to the vaccine against meningococcus also protects main alternatives (penicillin, sulfamids, tetracycline, fluoroquinolones, macrolides), are described as “superbacterial gonorrhea” or “super gonorrhees”.

Neisseria Meningitidis. For example, Neisseria Gonorrhoeae des Points Communs

A genomic analysis of 970 isolates of Neisseria gonorrhoeae collected by surveillance in the United States, compared to the reference sequences of Neisseria meningitidis Serogroup B (NMB), identified 1,525 proteins common to the two species, in particular external membrane proteins. Similarly, The two bacteria share 80 to 90 % of their genomic sequences (2). Nevertheless, Previous studies had already shown that a cross protection against gonococcal infections could be conferred by vaccines with external. membrane (OMV) of meningococcus B. The meningococcal B vaccine (MENB) thus emerges as a promising and unexpected track for the prevention of the gonorrhea.

In the late 1990s and early 2000s, New Zealand experienced an epidemic of meningitis N. meningitidis From group B. To stop it, the Ministry of Health launched between 2004 and vaccine against meningococcus also protects 2006 the “Menzb vaccination program” providing free vaccination to under 20. A retrospective study case-control published in The Lancet In 2017. compared the incidence of gonorrhea between menzb vaccinated subjects and not vaccinated. The results have shown a 31 % reduction in gonococcal infections in vaccinated (3). Similar decreases in gonorrhea levels have been reported in Canada. Cuba, Norway, Australia and the United States after their MENB vaccination campaigns. In France. the Doxyvac study confirmed this trend with a reduction of 50 % of gonococcus infections in people vaccinated by 4Cmenb (BexSero®) (4).

Note that among the MENB vaccines. only the 4Cmenb vaccine, which targets external membrane vesicles of the bacteria, seemed to ensure protection against gonorrhea (5).

In a recent study. funded by the European Research Council and published in Science Translational Medicinethe authors sought to understand the mechanisms of this cross protection (6, 7).

Porb. Los: Antigens of cross protection

This study vaccine against meningococcus also protects aimed to identify antibodies induced by the MENB vaccine capable of also neutralizing gonococci, in the event that these antibodies could reveal the specific antigens responsible for cross protection.

Researchers have taken blood samples from 3 volunteers vaccinated by the 4Cmenb. The B cells were isolated and then sorted individually to identify antibodies capable of killing gonococci in a bactericidal test.

On nearly 400 antibodies tested, 17 have proven to be clinically significant with a lethal action against gonococci. Nine of these antibodies recognized the porine B antigen (porb) – all derived from the germinal lineage IGHV4-34 With a region determining complementarity 3 of unusually long heavy chain -4 recognized lipooligosaccharide (LOS). 4 had an unknown specificity.

PORB. abundant protein on the surface of gonococcus and meningococcus, as well as the LOS structures common to the two bacteria, emerge as key antigens of cross immunity.

Protective efficiency has been demonstrated in vain : After vaccine against meningococcus also protects vaginal infection of 42 mice by gonococci. only 36 % of the mice processed by the anti-port antibody were colonized, against 78 % in the control group.

These results provide a mechanistic explanation for clinically observed cross protection: Porb. Los antigens, common to the two bacteria, constitute the privileged targets of neutralizing antibodies induced by the MENB vaccine.

According to the authors, this discovery opens up new therapeutic perspectives. On the one hand, a future specific Gonorrhea vaccine should primarily integrate Porb and Los antigens to optimize its effectiveness. On the other hand. anti-port and anti-los monoclonal antibodies could constitute a promising therapeutic alternative in the face of the increasing antibiotic resistance of gonococcus.

The 4Cmenb vaccine: the future of the prevention of gonorrhea?

Neisseria meningitidis share a strong genetic proximity with Neisseria gonorrhoeaeresponsible for the Gonorrhea. The 4Cmenb vaccine. which contains surface proteins of meningococcus B (in particular external membrane vesicles), would reduce vaccine against meningococcus also protects the risk of gonococcal infection from 33 to 50 % depending on studies (7).

Faced with the growing antibiotic resistance of gonococcus. in the absence of a specific vaccine, the use of 4Cmenb represents a promising transient preventive strategy.

This approach finds its first concrete application across the Channel: faced with an epidemic flambé of Gonorrhea reaching record levels. the National Health Service (NHS) English recently announced the deployment of the 4Cmenb vaccine among high-risk populations, in particular men with sex with men with recent history of multiple partners or STS (8).

This pioneering program is the world’s first use of a meningococcal vaccine in gonorrhea prevention.

Vaccine against meningococcus also protects

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