Short- and long-term impact of vaccination against cytomegalovirus: a modeling study

Ganna Rozhnova,Debbie Van Baarle,Marjolein Korndewal,Ann C Vossen,Fiona Van Der Klis,Michiel Van Boven,Mirjam E Kretzschmar

doi:10.1186/s12916-020-01629-3

Abstract

BackgroundInfection with cytomegalovirus (CMV) is highly prevalent worldwide and can cause severe disease in immunocompromised persons and congenitally infected infants. The disease burden caused by congenital CMV infection is high, especially in resource-limited countries. Vaccines are currently under development for various target groups.MethodsWe evaluated the impact of vaccination strategies and hygiene intervention using transmission models. Model parameters were estimated from a cross-sectional serological population study (n=5179) and a retrospective birth cohort (n=31,484), providing information on the age- and sex-specific CMV prevalence and on the birth prevalence of congenital CMV (cCMV).ResultsThe analyses show that vertical transmission and infectious reactivation are the main drivers of transmission. Vaccination strategies aimed at reducing transmission from mother to child (vaccinating pregnant women or women of reproductive age) can yield substantial reductions of cCMV in 20 years (31.7–71.4% if 70% of women are effectively vaccinated). Alternatively, hygiene intervention aimed at preventing CMV infection and re-infection of women of reproductive age from young children is expected to reduce cCMV by less than 2%. The effects of large-scale vaccination on CMV prevalence can be substantial, owing to the moderate transmissibility of CMV at the population level. However, as CMV causes lifelong infection, the timescale on which reductions in CMV prevalence are expected is in the order of several decades. Elimination of CMV infection in the long run is only feasible for a vaccine with a long duration of protection and high vaccination coverage.ConclusionsVaccination is an effective intervention to reduce the birth prevalence of cCMV. Population-level reductions in CMV prevalence can only be achieved on a long timescale. Our results stress the value of vaccinating pregnant women and women of childbearing age and provide support for the development of CMV vaccines and early planning of vaccination scenarios and rollouts.

Highlights

Infection with cytomegalovirus (CMV) is highly prevalent worldwide and can cause severe disease in immunocompromised persons and congenitally infected infants
In a study from Belgium, the burden of disease due to congenital CMV infection (cCMV) was estimated at 18 disabilityadjusted life years (DALYs) per 100,000 in Belgium for 2013, and ten times higher than the burden caused by congenital toxoplasmosis [13]
Based on quantitative estimates of key parameters, we evaluate the effectiveness of a suite of vaccination strategies and hygiene intervention decreasing infectious contacts of women of reproductive age and young children

Summary

Introduction

Infection with cytomegalovirus (CMV) is highly prevalent worldwide and can cause severe disease in immunocompromised persons and congenitally infected infants. The high prevalence of maternal CMV infection and incidence of cCMV worldwide [3, 15,16,17,18] has motivated the development of vaccines [19, 20]. No vaccine is as yet registered, but several candidate vaccines are well past the stage of early development and are being evaluated in clinical trials [20,21,22] Another preventive option to reduce cCMV is hygiene intervention [23,24,25,26], whose effectiveness among seronegative pregnant women with exposure to young children has been supported by several studies [23, 25]

Methods

Results

Discussion

Conclusion