Rubella vaccination in India: identifying broad consequences of vaccine introduction and key knowledge gaps

Abstract

SUMMARYRubella virus infection typically presents as a mild illness in children; however, infection during pregnancy may cause the birth of an infant with congenital rubella syndrome (CRS). As of February 2017, India began introducing rubella-containing vaccine (RCV) into the public-sector childhood vaccination programme. Low-level RCV coverage among children over several years can result in an increase in CRS incidence by increasing the average age of infection without sufficiently reducing rubella incidence. We evaluated the impact of RCV introduction on CRS incidence across India's heterogeneous demographic and epidemiological contexts. We used a deterministic age-structured model that reflects Indian states’ rural and urban area-specific demography and vaccination coverage levels to simulate rubella dynamics and estimate CRS incidence with and without RCV introduction to the public sector. Our analysis suggests that current low-level private-sector vaccination has already slightly increased the burden of CRS in India. We additionally found that the effect of public-sector RCV introduction depends on the basic reproductive number, R0, of rubella. If R0 is five, a value empirically estimated from an array of settings, CRS incidence post-RCV introduction will likely decrease. However, if R0 is seven or nine, some states may experience short-term or annual increases in CRS, even if a long-term total reduction in cases (30 years) is expected. Investment in population-based serological surveys and India's fever/rash surveillance system will be key to monitoring the success of the vaccination programme.

Seroprevalence of Rubella Virus-specific Antibodies in Women and the Diagnostic Efficacy of Enzyme-linked Immunoassay and Rapid Immunochromatographic Tests

“…Studies have also noted that the MMR immunization status among children was well below 50%. The Indian government, therefore, had included the Rubella vaccine in the National Immunization Program from 2017 [6].…”

“…The measles, mumps, and rubella (MMR) vaccine was available in India since 2000, but only recently, i.e., in 2017, the Rubella-containing vaccine was introduced in the National Immunization Schedule [6]. It, therefore, is imperative that the current Rubella vaccination is insufficient, and the virus may still be circulating among the population, which poses a threat to pregnant women and the fetus.…”

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“…Pathogenesis: Following respiratory transmission of rubella infection, replication of the infection is thought to happen in the nasopharynx and territorial lymph hubs 53 . A viremia happens 5 to 7 days after the introduction with spread of the infection all through body 54 . Transplacental contamination of the embryo happens amid viremia.…”

Estimating age-mixing patterns relevant for the transmission of airborne infections

“…This has implications for the age targeting of vaccines or other intervention measures. In another mathematical modelling study, Winter et al (2018) showed that incorporating age-mixing patterns decreased the projected estimates of reductions in congenital rubella syndrome attained from introducing public-sector rubella vaccination (Winter et al, 2018).…”