Modeling gonorrhea vaccination to find optimal targeting strategies that balance impact with cost-effectiveness.

Abstract

Vaccination for UK men who have sex with men (MSM) at increased gonorrhea risk has been advised, but not yet implemented. Effective targeting is essential for cost-effectiveness, but previously-examined approaches have disadvantages: Vaccination-on-Diagnosis has low coverage (limiting impact), and Vaccination-according-to-Risk requires asking about sexual behavior to identify at-risk individuals, which is not always feasible. We developed a transmission-dynamic model to evaluate novel strategies offering vaccination based on information readily available to clinicians (diagnostic/vaccination history, if the patient is seeking care due to partner notification). Offering vaccination to MSM who are notified partners of gonorrhea cases or were diagnosed themselves in the past 2 years averts 1.6x more cases and is more cost-effective than Vaccination-on-Diagnosis. If vaccination provides 20% protection for 1.5 years after primary vaccination and 3 years after revaccination then at £18/dose administered, all considered strategies have ≥50 and ≥90% probabilities of positive net monetary benefit compared with no vaccination with a quality-adjusted life year valued at £20,000 and £30,000 respectively, thus meeting the UK criteria for cost-effectiveness. All novel strategies considered achieve greater impact than Vaccination-on-Diagnosis without the feasibility issues of Vaccination-according-to-Risk.