Progress Toward Rubella and Congenital Rubella Syndrome …

Discussion

Progress toward rubella elimination has accelerated since 2012, and in 2020, rubella elimination had been verified in approximately one half of the countries in the world. The considerable progress made toward elimination has been driven by the establishment of regional WHO rubella elimination goals, an increase in commitment to elimination by countries, and the availability of financial support from global partners for RCV introduction.

Progress is reflected in an increase in the number of countries introducing RCV into national childhood immunization schedules and the coverage achieved. From 2012 to 2020, the number of countries that have introduced RCV increased from 132 to 173, and global coverage increased from 40% to 70%. Although vaccine availability increased, as more low-income countries and lower middle-income countries have introduced RCV, coverage estimates continue to reflect barriers to access in lower-income groups; however, coverage declined only one percentage point from 2019 to 2020 during the COVID-19 pandemic.

Progress has also been reflected in the decline in reported rubella cases, including a 48% decrease during 2012–2019, with a further decrease in 2020. The extent to which rubella transmission declined in 2020 is unclear, however, because fewer reported cases might reflect the impact of COVID-19 mitigation measures or an underreporting of cases in 2020 because of reductions in health care–seeking behavior from patients, health facility availability and reporting, or overall pandemic-related health system disruptions (9). The increase in the number of reported CRS cases during 2012–2020 reflects improved surveillance in several populous countries that initiated CRS surveillance after 2012, rather than an increase in rubella among susceptible pregnant women and CRS in their infants. The Measles and Rubella Strategic Framework 2021–2030 outlines potential actions to improve surveillance, including strengthening comprehensive surveillance supported by laboratory networks; promoting training of health workers in early detection, notification and investigation of cases using standardized definitions, tools, and templates for collecting data; and supplementing routine data collection with serosurveys to identify immunity gaps (8).

In countries that have not yet introduced RCV, providing policy makers with data on the impact of the investment to introduce RCV can help them determine whether their country should introduce RCV. The decision-making process benefits from 1) evaluation of the impact of RCV introduction on CRS, 2) consideration of the opportunities offered by accelerated measles elimination activities, and 3) evaluation of the long-term sustainability of financing for RCV along with other vaccines (3). Countries that had initially introduced RCV in selected populations (usually females only) to control CRS or that introduced RCV without a wide age-range campaign, should identify and address existing immunity gaps to achieve elimination. The Immunization Agenda 2030, the global immunization strategy for 2021–2030, includes rubella in its call for five regions to achieve elimination targets (10). Because all six WHO Regions have either established or expressed a commitment to rubella elimination, recommended strategic priorities include improving the collection and use of surveillance data, increasing community demand for and coverage with RCVs, and ensuring the availability of vaccine supplies and laboratory reagents (8). Because rubella and measles vaccines are administered as a combined vaccine and the surveillance systems are intricately connected, the progress toward rubella elimination might be a motivating marker of progress toward measles elimination.

The findings in this report are subject to at least two limitations. First, the accuracy and reliability of surveillance and immunization data remain a challenge, limiting the ability to identify immunity gaps, to focus immunization-strengthening activities, and to demonstrate the interruption of rubella virus transmission. Second, the decrease in the number of countries reporting and the effects of the COVID-19 pandemic on the quality of surveillance data limit the ability to monitor progress in 2020.

Considerable progress has been made in control and elimination of rubella and CRS since 2012. By 2020, only 21 (11%) countries have yet to introduce RCV into the immunization schedule, global RCV coverage has increased by 30%, and one region has eliminated rubella and a second region is close. The commitment to elimination by all regions indicates that global rubella elimination is in sight. As the remaining countries introduce RCVs, surveillance and coverage data will become crucial to identifying and closing immunity gaps and maintaining high routine coverage, with periodic campaigns conducted as necessary to achieve and maintain elimination status.