Epidemiological profile and progress toward rubella elimination in China. 10 years after nationwide introduction of rubella vaccine

Abstract

Background: Rubella-containing vaccine (RCV) became available in China in 1993 and was introduced nationwide into the Expanded Immunization Program (EPI) in 2008. We evaluated implementation and impact of RCV from 2 years prior to nationwide introduction through the 10 years after nationwide introduction.

Methods: We analyzed RCV lot-release (doses distributed) data, 1- and 2-dose RCV coverage, and rubella data from China's nationwide disease surveillance system to describe the current status and changes in rubella epidemiology between 2005 and 2017.

Results: While the vaccine was included into the routine immunization program in 2008, its full implementation required 4 years due to sporadic vaccine supply constraints. RCV1 and RCV2 coverage increased from 51.5% and 39.0% in 2008 to >95% during 2012 through 2016. From 2005 to 2017, the annual incidences (per million) of rubella ranged from 91.09 in 2008 down to 1.16 in 2017; reductions occurred in all age groups. The proportion of cases among individuals ≥20 years old increased from 0.97% in 2005 to 31.2% in 2017. In the better-developed eastern China, most cases were among adults; in central and western China, most cases were among children or adolescents.

Conclusions: The marked decrease rubella was a result of inclusion of RCVs into EPI targeting children less than 2 years of age and achieving high level of 2-dose coverage. Rubella was reduced in absolute terms, and its epidemiology was changed to older cases with substantial inter-province variation. Ensuring full vaccination of school children and identifying strategies to reach adults with measles and rubella combined vaccines will be important to hasten elimination of rubella and prevent CRS outbreaks.

Keywords: Elimination; Rubella; Surveillance.