OBJECTIVES: Cytomegalovirus (CMV) infection in healthy individuals is often mild or asymptomatic; however, a pregnant woman can pass CMV to her newborn, resulting in congenital cytomegalovirus (cCMV), the major infectious cause of sensorineural hearing loss in infants born in developed countries. There are no prophylactic vaccines currently available to prevent CMV.
METHODS: A dynamic transmission model was developed to evaluate the incremental impact of routine pediatric CMV vaccination in the US population, compared to no vaccination. We modelled an initial 1-year catch-up vaccination of children aged 6 months to 3 years, then only newly eligible children aged 6 months were vaccinated in subsequent years. Two vaccine coverage scenarios were modelled: 100% and 50% coverage. Using conservative assumptions, efficacy against primary infection for the 2-dose vaccine regimen was 70% in the first 2 years then waned to zero over the next 5 years; no efficacy was assumed against non-primary infection. Health outcomes included CMV infections (primary and non-primary) and cCMV cases (symptomatic cCMV, neonatal death, and cCMV-related stillbirth) averted. Sensitivity analyses assessed the robustness of parameter estimates.
RESULTS: Based on 100% pediatric vaccination coverage in the US population, we expected a mean annual reduction of 12,712 cCMV cases (including 1,213 symptomatic cCMV cases). In the 50% pediatric vaccination coverage scenario, a mean annual reduction of 12,375 cCMV cases (including 1,181 symptomatic cCMV cases) was expected (see Table 1).
CONCLUSIONS: There is substantial public health benefit associated with utilization of an effective CMV vaccine in US children due to the potential reduction in CMV transmission. Several model parameters were based on assumptions and robust evidence generation is needed. Furthermore, the efficacy and durability of a licensed vaccine are unknown and will be important considerations.
