Table 8.

Overview of modelling studies on gonococcal vaccines that measure anticipated socio-economic impact of the vaccine.

Policy question	Assessment method/measure	Additional information specific to models	Assumptions	Outcomes/ interpretation
Potential health and economic benefits of combating antibiotic-resistant gonorrhoea in the United States[131]	Impact on AMR	Two scenarios were modelled: (1) The prevalence of cephalosporin-resistant gonorrhoea remains at 2% (2) The prevalence of cephalosporin-resistant gonorrhoea increased linearly from 2% at the start to 15% after six years and then at 15% until year 10.	Emergence of cephalosporin-resistant gonorrhoea would have a similar impact on gonorrhoea incidence to the emergence of ciprofloxacin resistance in the late 1990s. Gonorrhoea incidence rate would remain constant if the percentage of cephalosporin-resistant gonococcal infection did not change. The annual number of gonococcal infections in the United States is 820,000 without emerging resistance. Lifetime cost per gonococcal infection in males assumed as US$86, and in females, US$383.	Compared to scenario 1, gonorrhoea rates in scenario 2 were estimated to be 2% higher in year 1, 14% higher in year 5, and 22% higher in year 10, which would result in an additional 1.2 million cases in a 10-year period, of which 579 would lead to gonorrhoea-attributable HIV infections. Additional cost in scenario 2 was estimated to be $378.2 million, which includes $170.5 million for treating gonorrhoea-attributable HIV infections Significant health and economic losses can be avoided by maintaining the prevalence of ceftriaxone-resistant N. gonorrhoeae to lower than 2%. The cost of implementing strategies to prevent emerging AMR, such as introducing a vaccine, can at least be partially offset by averting the costs of emerging resistance.
To compare the impact of possible gonorrhoea vaccination with the current standard of treatment with antibiotics; the economically justifiable price of potential gonorrhoea vaccines [126]	Cost-effectiveness analysis / QALYs	Decision-analytic model Sensitivity analyses revealed that most costs and QALYs gained by the vaccination program were achieved through co-reduction of gonorrhoea-attributable HIV infections. The vaccine’s cost-effectiveness was affected by the efficacy of available antibiotic treatment. Higher antibiotic efficacy would result in lower cost-effectiveness for vaccination. If the cost of new antibiotic treatment was higher than today’s available option, then vaccination would be more cost-effective.	Vaccine efficacy of 20% against gonorrhoea with an average duration of effect of 10 years. A theoretical cohort consisting of 2,047,000 men and 1,957,000 women aged 15 years old was used in this model. Vaccination rate of 75%. The same vaccination rate was assumed for men and women and at-risk populations. This model has a reinfection rate of 4.5% per disease cycle. For each case of N. gonorrhoeae infection prevented through the vaccination program, an additional 0.5 cases would be prevented in the general population. 97% efficacy of antibiotics for treating gonorrhoea.	The model predicts that for the given vaccine efficacy and timeframe, 83,617 N. gonorrhoeae infections (disregarding first infection or reinfection) can be prevented within the theoretical cohort over a lifetime. Without vaccination, the model predicts 844,000 N. gonorrhoeae infections within this cohort. 1,265 quality-adjusted life-years (QALYs) could be saved by vaccinating the theoretical cohort. Without vaccination, the model predicts a loss of 14,106 QALYs within this cohort. Direct medical cost decreases by $28.7 million from $56 million in the unvaccinated scenario. Income and productivity losses would reduce to $40.0 million from $75 million per unvaccinated cohort. Even at low effectiveness of just 20%, the gonococcal vaccine could still substantially reduce the disease burden and cost to justify a price of $26.10 per dose.