A meningitis vaccine could be cost-effective in combating gonorrhea amid rising cases globally and increased resistance to drug treatments, according to a news release.
This is the finding of a new modelling study published in The Lancet Infectious Diseases journal, which looked at the cost effectiveness of using a vaccine for meningitis B (called ‘Bexsero’) to protect against gonorrhea.
Gonorrhea is a sexually transmitted infection (STI) caused by bacteria which, if untreated, can lead to serious health conditions. The World Health Organization has designated gonorrhea a public health priority, with rising case numbers globally and increases in bacterial resistance to drug treatments raising concerns that gonorrhea may become untreatable.
There are currently no approved vaccines against gonorrhea.
Previously, researchers in New Zealand showed that a vaccine used to prevent meningitis offered some protection against gonorrhea, and it was expected that the similar Bexsero vaccine would be more protective – which has now been confirmed by a separate study.
The question for public health decision makers is, does Bexsero provide sufficient protection to be cost-effective to use against gonorrhea?
This Imperial modeling study is the first cost effectiveness analysis of any vaccine against gonorrhea that accounts for the impact of vaccination on future transmission and diagnoses. The researchers considered the costs of vaccination, the cost savings from reduced testing and treatment of gonorrhea infections, and the value of health gains from averting illness. They found that vaccination could save money overall as well as benefiting health.
In the analysis, researchers considered men who have sex with men (MSM), who are a key affected group internationally, and in England they have the highest incidence of infection – accounting for almost half of diagnosed cases – and the greatest risk of having drug-resistant infection.
The modelling found that it would be cost-effective to use Bexsero to protect MSM against gonorrhea, provided it were offered to those at higher risk of infection, to maximize the benefit per dose administered.
Offering vaccination to all MSM in England attending sexual health clinics for STI testing was not considered to be a cost-effective approach because it would be expensive, and an alternative approach could achieve a similar health benefit while actually saving money.
Offering vaccination to those with a confirmed gonorrhea diagnosis (who are statistically at higher risk of being infected again in the future) would likely be cost-effective, preventing more than 43,900 cases and save more than £2.2 million over 10 years.
Offering vaccination based on future risk of infection (meaning those diagnosed with gonorrhea plus those reporting high numbers of sexual partners) could prevent even more cases (more than 110,200) and saves even more money (more than £7.9 million) – however, this approach requires asking patients about sexual behavior, which they might not wish to disclose making it potentially harder to implement.
With efforts underway to produce vaccines specifically to protect against gonorrhea, an important additional finding is that improving efficacy increases a vaccine’s value more than improving duration of protection.
Professor Peter White, of Imperial College London, said: “We found the most cost-effective approach is offering vaccination to those men who have sex with men (MSM) at highest risk, but this requires asking about sexual behavior which might be sensitive for some people and so it might be difficult to do in practice, so we recommend sexual health clinics conduct a feasibility study. If we can’t put this approach into practice, then an alternative pragmatic approach is offering vaccination to all MSM testing positive for gonorrhea, as being diagnosed with gonorrhea is an indicator of risk of future infection.”
Dr Lilith Whittles of Imperial College London said: “If existing meningitis vaccines were targeted towards at-risk groups, they would not only have a large impact on the gonorrhea epidemic in men who have sex with men but could also save costs to the NHS. To inform vaccine developers, we found that although current vaccine-protection is likely to be relatively short-lived, meaning repeated boosters would be needed, improving efficacy increases the value of a vaccine more than improving the duration of protection.”
