The VMI is working on strategic models to explore when countries should embark on rubella vaccination and/or elimination efforts.
Rubella is usually a mild childhood disease, but infection during pregnancy can lead to fetal death or congenital rubella syndrome (CRS). Vaccination provides the opportunity to reduce CRS burdens, but inadequate infant vaccination coverage can increase CRS incidence by raising the average age at infection. Current WHO recommendations are that routine vaccination should only be undertaken if coverage of 80% of each birth cohort can be sustained. The VMI is analyzing uniquely detailed rubella datasets from Peru and Mexico to better define rubella’s epidemiology. These analyses highlight the importance of stochasticity and provide insight in population characteristics that determine extinction of epidemics or increases in the burden of CRS.
Following these empirical analyses, we developed general strategic models to tackle the question of what coverage levels are required to retain the burden of CRS below the burden occurring pre-vaccination across a range of seasonal forcing, birth rates, and transmission. Overall, this work provides insight in strategies and determinants for the introduction of rubella vaccination into current infant vaccination programs.