Modelling rubella in Europe

Abstract

The prevention of congenital rubella syndrome (CRS), as a complication of rubella infection during pregnancy, is the main aim of rubella vaccination programmes. However, as vaccination of infants leads to an increase in the average age at which those who were not immunized become infected, certain rubella vaccination programmes can lead to an increase in the incidence of CRS. In this paper we use a mathematical model of the transmission dynamics of rubella virus to investigate the likely impact of different vaccination policies in Europe. The model was able to capture pre- and post-vaccination patterns of infection and prevalence of serological markers under a wide variety of scenarios, suggesting that the model structure and parameter estimates were appropriate. Analytical and numerical results suggest that endemic circulation of rubella is unlikely in Finland, the United Kingdom, The Netherlands, and perhaps Denmark, provided vaccine coverage is uniform across geographical and social groups. In Italy and Germany vaccine coverage in infancy has not been sufficient to interrupt rubella transmission, and continued epidemics of CRS seem probable. It seems unlikely that the immunization programmes in these countries are doing more harm than good, but this may be partly as a result of selective immunization of schoolgirls. Indeed, in both these countries, selective vaccination of schoolgirls with inadequate vaccination histories is likely to be an important mechanism by which CRS incidence is suppressed (unlike the other countries, which have had sufficiently high infant coverage rates to withdraw this option). Reducing inequalities in the uptake of rubella vaccine may bring greater health benefits than increasing the mean level of coverage.

Structured models of infectious disease: Inference with discrete data

“…3a), and shows slight regional differences. With life-expectancy of around L =66 in Costa Rica in 1969, using the relationship R 0 ~1+ L/A (Anderson and May, 1991), this suggests a rather low R 0 (between 3 and 5), comparable with R 0 estimates of between 2 and 8 reported for rubella Europe (Edmunds et al, 2000a; Edmunds et al, 2000b). To estimate the force of infection over age, we used the 'catalytic' model (Griffiths, 1974), so called because of it structural similarity to equations commonly used to study of chemical reactions (Grenfell and Anderson, 1985).…”

“…Since routine vaccination generally decreases the force of infection (FOI, the rate at which susceptible individuals become infected), it will increase the average age of infection unless coverage is high enough to achieve elimination. Mass vaccination may therefore potentially have the negative side effect of increasing CRS incidence (Anderson and May, 1983; Anderson and May, 1985; Anderson and May, 1991; Edmunds et al, 2000b; Vynnycky et al, 2003). Dynamically speaking, mass vaccination is analogous to reducing the birth rate, if vaccine-induced immunity conveys life-long protection (Earn et al, 2000).…”

An epidemiological assessment towards elimination of rubella and congenital rubella syndrome in Singapore

“…The NPSS 2008-2010 confirmed the high overall seroprevalence of rubella (88.5%, CI 86.6-90.2) in children and adolescents aged 1-17 years. Estimates based on European sero-epidemiological data suggest that a seropositivity of 70-87% is sufficient to eliminate rubella infection [31].…”

The pre-vaccination regional epidemiological landscape of measles in Italy: contact patterns, effort needed for eradication, and comparison with other regions of Europe

“…Rather than being essentially homologous, as implicit in the EURO conjecture, the possibility that patterns of infection by measles throughout Europe could be and have been largely different (as by the way suggested for rubella by Edmunds et al . [26]) is a stimulating one. Our results provide many indications that infection patterns in Italy could indeed deviate from the "EURO" standard.…”