Introduction of rubella-containing-vaccine to Madagascar: implications for roll-out and local elimination

Abstract

Few countries in Africa currently include rubella-containing vaccination (RCV) in their immunization schedule. The Global Alliance for Vaccines Initiative (GAVI) recently opened a funding window that has motivated more widespread roll-out of RCV. As countries plan RCV introductions, an understanding of the existing burden, spatial patterns of vaccine coverage, and the impact of patterns of local extinction and reintroduction for rubella will be critical to developing effective programmes. As one of the first countries proposing RCV introduction in part with GAVI funding, Madagascar provides a powerful and timely case study. We analyse serological data from measles surveillance systems to characterize the epidemiology of rubella in Madagascar. Combining these results with data on measles vaccination delivery, we develop an age-structured model to simulate rubella vaccination scenarios and evaluate the dynamics of rubella and the burden of congenital rubella syndrome (CRS) across Madagascar. We additionally evaluate the drivers of spatial heterogeneity in age of infection to identify focal locations where vaccine surveillance should be strengthened and where challenges to successful vaccination introduction are expected. Our analyses indicate that characteristics of rubella in Madagascar are in line with global observations, with an average age of infection near 7 years, and an impact of frequent local extinction with reintroductions causing localized epidemics. Modelling results indicate that introduction of RCV into the routine programme alone may initially decrease rubella incidence but then result in cumulative increases in the burden of CRS in some regions (and transient increases in this burden in many regions). Deployment of RCV with regular supplementary campaigns will mitigate these outcomes. Results suggest that introduction of RCV offers a potential for elimination of rubella in Madagascar, but also emphasize both that targeted vaccination is likely to be a lynchpin of this success, and the public health vigilance that this introduction will require.

Predicting congenital rubella syndrome in Japan, 2018–2019

“…CRS is the most severe sequela of rubella, involving congenital cardiac, cerebral, ophthalmic, and auditory defects (Duszak, 2009;Lambert et al, 2015). To control rubella, vaccination is required (Zanetta et al, 2003;Wesolowski et al, 2016). As vaccination could elevate the age at infection (Amaku et al, 2003;Berger et al, 2011;Mossong et al, 2008;Tanaka et al, 2017;Saito et al, 2018), controversial routine immunization with low vaccination coverage is known to be accompanied by an increase in CRS (Best et al, 2005;Chua et al, 2015;Panagiotopoulos et al, 1999).…”

A Critical Review of the Articles “Rubella Outbreak Investigation, Gokwe North District, Midlands Province, Zimbabwe 2014

“…Another of African countries are also introducing Rubella vaccination. This is having a further effect of strengthening meascles vaccination (Wesolowski et. al.…”

Unintended consequences and the paradox of control: Management of emerging pathogens with age-specific virulence

“…For a disease in which outcome severity can increase with age, such as rubella [ 10 – 12 ] or ZVD, decreases in the attack rate can shift cases into more vulnerable age classes. This may result in a “paradox of control” in which a reduction in incidence increases mortality and morbidity [ 13 , 14 ]. The paradox of control can lead to situations with multiple locally optimal management equilibria [ 15 , 16 ] and is the reason current WHO policy for rubella vaccination does not recommend implementing routine coverage below a threshold that is expected to reduce both total incidence and incidence in most-affected classes.…”