Body & Fitness

Kiwi vaccine programme for meningococcal B has reduced incidences of gonorrhoea

Welcome news in light of the fact that gonorrhoea is on the rise worldwide.

A vaccinination programme in New Zealand for meningococcal B has reduced incidences of gonorrhoea.

In the face of a global gonorrhoea crisis, a New Zealand vaccination programme has been shown to reduce incidences of gonorrhoea in those vaccinated.

Cases of gonorrhoea are on the rise worldwide and the sexually transmissible infection is becoming much harder to treat – sometimes impossible – because the bacteria is becoming resistant to antibiotics.

Yet a mass vaccination programme in New Zealand against meningococcal B has led to a drop in cases of gonorrhoea in vaccinated people compared to unvaccinated people, new research shows.

The study of more than 14,000 people that was published in The Lancet found that having previously received the meningococcal vaccine reduced the incidence of gonorrhoea by approximately 31 per cent.

This is the first time that a vaccine has shown any protection against gonorrhoea, and may provide a new avenue for vaccine development.

Gonorrhoea is on the rise worldwide.

Although the two diseases are very different, there is an 80 to 90 per cent genetic match between the bacteria that cause them, providing a biologically plausible mechanism for cross-protection.

So far, efforts to develop a vaccine against gonorrhoea have been unsuccessful despite more than a century of research.

Four vaccine candidates have reached clinical trial stage but none have been effective.

Gonorrhoea is on the up worldwide, the World Health Organisation (WHO) found after looking at data from 77 countries, due to widespread resistance to older and cheaper antibiotics.

“The bacteria that cause gonorrhoea are particularly smart. Every time we use a new class of antibiotics to treat the infection, the bacteria evolve to resist them,” said Dr Teodora Wi, Medical Officer, Human Reproduction, at the WHO.

WHO found that some countries – particularly high-income ones, where surveillance is best – are finding cases of the infection that are untreatable by all known antibiotics.

“These cases may just be the tip of the iceberg, since systems to diagnose and report untreatable infections are lacking in lower-income countries where gonorrhoea is actually more common,” adds Dr Wi.

A plan to tackle multi-drug-resistant gonorrhea has been published by experts.

Each year, an estimated 78 million people worldwide are infected with gonorrhoea. In New Zealand 70 cases in every 100,000 people were reported in the Ministry of Health’s most recent Public Health Surveillance STI clinic annual report.

Worryingly, gonorrhoea often presents no noticeable symptoms yet if left untreated it can lead to pelvic inflammatory disease, ectopic pregnancy and infertility. Your best defense is to always wear a condom.

Look out for these symptoms:

For women:

• vaginal discharge

• bleeding between periods

• lower abdominal pain

• pain during sex

For men:

• pain when urinating

• discharge from the penis or rectum

• pain in the testicles

To get yourself checked out visit your GP or go to your nearest Family Planning clinic.

The science behind it

Around 1 million people (81 per cent of the population under 20 years) received the MeNZB vaccine, an OMV meningococcal group B vaccine, in New Zealand in 2004-2006, which provided researchers with a unique opportunity to test the cross-protection hypothesis.

The MeNZB vaccine was developed to control a meningitis epidemic and is no longer available, but the OMV antigens thought to provoke the immune response to gonorrhoea have been included in the more recently developed 4CMenB vaccine, available in many countries.

In this study, researchers used data for all people aged 15-30 who had been diagnosed with gonorrhoea or chlamydia, or both, at 11 sexual health clinics and who were eligible to receive the MeNZB vaccine during the 2004-2006 vaccination programme.

Cases had laboratory-confirmed gonorrhoea, and controls had laboratory-confirmed chlamydia.

A total of 14,730 cases and controls were included in the analysis. Vaccinated individuals were significantly less likely to have gonorrhoea than controls (41 per cent vs 51 per cent).

Taking into account all other factors such as ethnicity, deprivation, geographical area, and gender, the researchers concluded that having previously received the MeNZB vaccine reduced the incidence of gonorrhoea by 31 per cent.

Lead author of the study, Dr Helen Petousis-Harris from the University of Auckland, says: “Our findings provide experimental evidence and a proof of principle that an OMV meningococcal group B vaccine could offer moderate cross-protection against gonorrhoea.

“This is the first time a vaccine has shown any protection against gonorrhoea. At the moment, the mechanism behind this immune response is unknown, but our findings could inform future vaccine development for both the meningococcal and gonorrhoea vaccines.”

The study authors say that more research is now needed to see whether other meningococcal vaccines have a similar effect.

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