Two doses of the vaccine are 33% effective against gonorrhoea in adolescents and young adults.

A new investigation of health records for 16-23-year-olds in New York City and Philadelphia, USA, from 2016 to 2018, found that receiving two doses of the meningitis vaccination 4CMenB gives 40% protection against gonorrhoea.

Meningitis vaccines could help improve protection against gonorrhoea amid rising cases globally and increasing bacterial resistance to drugs used to treat the infection, according to findings from three linked papers published in The Lancet Infectious Diseases journal.

Gonorrhoea is a sexually transmitted infection (STI) which, if untreated, can lead to serious health conditions, including infertility in women, transmission to newborn babies, and increased risk of HIV. More than 80 million new cases of gonorrhoea were recorded worldwide in 2020.

The declining effectiveness of drug treatments for the bacteria responsible – Neisseria gonorrhoeae – and the lack of a licensed vaccine to prevent the infection have raised concerns about the possibility that gonorrhoea may become more resistant to treatment, or even untreatable, in future.

Meningitis vaccines have been recommended by the WHO as part of its roadmap to reduce the global burden of meningitis. This includes offering meningitis vaccines as part of routine childhood immunisation strategies. [2] Since meningitis vaccines have become more widely available, studies have shown they also offer some protection against gonorrhoea, and that even partial protection could reduce cases of the infection considerably. However, questions have remained about the impacts and effectiveness of using meningitis vaccines against gonorrhoea.

In 2016, the WHO set a target to reduce gonorrhoea incidences by 90% by 2030, however, an effective vaccine has yet to be developed. The three studies suggest that the 4CMenB vaccine may offer significant protection to young adults, and to men who have sex with men who might be at higher risk of infection.

Meningitis vaccine 4CMenB provides 40% protection against gonorrhoea

An observational study led by Dr Winston Abara, of U.S. Centers for Disease Control and Prevention, used health records to identify laboratory-confirmed cases of gonorrhoea and chlamydia – another leading STI – among 16–23-year-olds in New York City, NY and Philadelphia, PA, from 2016–2018. These cases were compared with immunisation records to determine people’s vaccination status with 4CMenB – which is licenced for use against meningitis – at the time of infection.

There were more than 167,000 infections (18,099 gonorrhoea, 124,876 chlamydia, and 24,731 co-infections) among almost 110,000 people. A total of 7,692 people had received the 4CMenB vaccine, with 4,032 (52%) receiving one dose, 3,596 (47%) two doses, and 64 (less than 1%) more than two doses. Full 4CMenB vaccination – receiving two doses – was estimated to provide 40% protection against gonorrhoea. One vaccine dose provided 26% protection.

Dr Winston Abara said: “Our findings suggest that meningitis vaccines that are even only moderately effective at protecting against gonorrhoea could have a major impact on prevention and control of the disease. Clinical trials focused on the use of 4CMenB against gonorrhoea are needed to better understand its protective effects and could also offer important insights towards the development of a vaccine specifically for gonorrhoea.”

The authors acknowledge some limitations. The findings may not be generalisable to wider groups because the data used were from people aged 16–23 years in two large urban settings in the USA. Additionally, use of surveillance data means it is possible some participants’ infection and vaccination status were misclassified, affecting the analysis.

Two-dose course of 4CMenB is 33% effective against gonorrhoea in adolescents and young adults

South Australia’s ongoing 4CMenB vaccination programme is the most extensive globally, initially involving infants, children, adolescents, and young adults with a continuing state-funded program for infants and adolescents. In an observational study led by Professor Helen Marshall, of the Women’s and Children’s Hospital in Adelaide, researchers assessed the effectiveness of 4CMenB against meningitis and gonorrhoea as part of an infant, child and adolescent vaccination programme.

The authors analysed meningitis and gonorrhoea infection data held by the Communicable Disease Control Branch, and 4CMenB vaccination records from the Australian Immunisation Register. To estimate the effectiveness of 4CMenB against gonorrhoea, patients diagnosed with chlamydia acted as controls because of similar sexual behavioural risks reported in patients with either infection.

More than 53,000 adolescents and young adults received at least one dose of 4CMenB during the vaccination programme’s first two years. As well as being highly effective against meningococcal B meningitis and sepsis, in adolescents and young adults a two-dose course of 4CMenB was 33% effective against gonorrhoea

Professor Helen Marshall said: “While recent studies have provided evidence that 4CMenB vaccination is associated with reduced risk of gonorrhoea, the vaccine was only offered to adolescents and young adults for short periods. The unprecedented scale of South Australia’s 4CMenB vaccination programme offers valuable real-world evidence of the vaccine’s effectiveness against meningococcal B meningitis in children and adolescents, and gonorrhoea in adolescents and young people. This information is vital to inform global meningitis vaccination programmes and policy decisions.” [3]

The authors acknowledge some limitations. While a meaningful reduction in the rate of gonorrhoea among adolescents and young adults was not observed, this was likely due to small case numbers in this age group. The reported effectiveness of 4CMenB against gonorrhoea is consistent with other studies. Co-infections of gonorrhoea and chlamydia may play an important role in disease spread and severity, but factors associated with rates of co-infections are not well understood. However, the analysis shows 4CMenB effectiveness was similar whether co-infections were included or not.

Writing in a linked Comment on both observational studies, Professor Jason Ong, Dr Magnus Unemo, Annabelle Choong, Victor Zhao, and Dr Eric Chow, who were not involved in the studies, highlight key measures to adopt while efforts to develop a gonorrhoea vaccine continue: “In the meantime, we must continue to strengthen prevention efforts, improve access to early diagnosis and evidence-based treatment (index cases and sexual contacts), ensure quality-assured global surveillance systems to inform treatment guidelines, and invest in rapid, reliable point-of-care tests (for detection of N gonorrhoeae and its antimicrobial resistance) and the development of novel therapeutic antimicrobials.”

Image Credit: Getty

You were reading: First Vaccine Shows 40% Protection Against Gonorrhoea Infection