Impact of birth rate, seasonality and transmission rate on minimum levels of coverage needed for rubella vaccination
Open Access
- 16 February 2012
- journal article
- Published by Cambridge University Press (CUP) in Epidemiology and Infection
- Vol. 140 (12), 2290-2301
- https://doi.org/10.1017/s0950268812000131
Abstract
SUMMARY Childhood rubella infection in early pregnancy can lead to fetal death or congenital rubella syndrome (CRS) with multiple disabilities. Reduction of transmission via universal vaccination can prevent CRS, but inadequate coverage may increase CRS numbers by increasing the average age at infection. Consequently, many countries do not vaccinate against rubella. The World Health Organization recommends that for safe rubella vaccination, at least 80% coverage of each birth cohort should be sustained. The nonlinear relationship between CRS burden and infection dynamics has been much studied; however, how the complex interaction between epidemic and demographic dynamics affects minimum safe levels of coverage has not been quantitatively evaluated across scales necessary for a global assessment. We modelled 30-year CRS burdens across epidemiological and demographic settings, including the effect of local interruption of transmission via stochastic fadeout. Necessary minimum vaccination coverage increases markedly with birth and transmission rates, independent of amplitude of seasonal fluctuations in transmission. Susceptible build-up in older age groups following local stochastic extinction of rubella increased CRS burden, indicating that spatial context is important. In low birth-rate settings, 80% routine coverage is a conservative guideline, particularly if supplemented with campaigns and vaccination of women of childbearing age. Where birth and transmission rates are high, immunization coverage must be well above 80% and campaigns may be needed. Policy-makers should be aware of the potential negative effect of local extinction of rubella, since heterogeneity in vaccination coverage will shape extinction patterns, potentially increasing CRS burdens.Keywords
This publication has 34 references indexed in Scilit:
- Measuring the Performance of Vaccination Programs Using Cross-Sectional Surveys: A Likelihood Framework and Retrospective AnalysisPLoS Medicine, 2011
- Maintaining high rates of measles immunization in AfricaEpidemiology and Infection, 2010
- The epidemiology of rubella in Mexico: seasonality, stochasticity and regional variationEpidemiology and Infection, 2010
- Rubella metapopulation dynamics and importance of spatial coupling to the risk of congenital rubella syndrome in PeruJournal of The Royal Society Interface, 2010
- Stage-structured transmission of phocine distemper virus in the Dutch 2002 outbreakProceedings. Biological sciences, 2009
- Interpreting time-series analyses for continuous-time biological models—measles as a case studyJournal of Theoretical Biology, 2003
- Estimation of the Basic Reproduction Number for Infectious Diseases from Age-Stratified Serological Survey DataJournal of the Royal Statistical Society Series C: Applied Statistics, 2001
- Time Series Modelling of Childhood Diseases: A Dynamical Systems ApproachJournal of the Royal Statistical Society Series C: Applied Statistics, 2000
- Modeling Measles, Mumps, and Rubella: Implications for the Design of Vaccination ProgramsInfection Control & Hospital Epidemiology, 1998
- A model-based evaluation of the national immunization programme against rubella infection and congenital rubella syndrome in The NetherlandsEpidemiology and Infection, 1998