Progress Toward Measles and Rubella Elimination — Indonesia, 2013–2022

Results

Immunization Activities

Routine immunizations. During 2013–2022, MCV1 coverage decreased approximately 3%, from 87% in 2013 to 84% in 2022; MCV2 coverage decreased approximately 12%, from 76% to 67% (Figure 1). RCV1 coverage increased from 15% in 2017 (the year RCV was introduced) to 84% in 2022 (Figure 2). During the COVID-19 pandemic, both measles and rubella vaccination coverage declined. In 2019, MCRV1 coverage was 88%; this declined to 76% in 2020 and to 72% in 2021. In 2019, MCRV2 coverage was 71%; this declined to 60% in 2020 and to 50% in 2021.

Supplementary immunization activities. In 2016, in response to measles outbreaks during 2014–2015, a nationwide follow-up measles SIA reached approximately 3.6 million children aged 9–59 months. In 2017 and 2018, as an integral component of RCV introduction, a MRCV SIA was conducted, reaching approximately 58 million children and adolescents aged 9 months to <15 years. In 2022, in response to the setbacks resulting from the COVID-19 pandemic, the Indonesian government sought to increase immunization coverage through Bulan Imunisasi Anak National (BIAN) or National Children Immunization Month, ^†† reaching approximately 26 million children with MRCV. Due in part to this campaign, MRCV1 coverage increased from 72% in 2021 to 84% in 2022, and MRCV2 coverage increased from 50% in 2021 to 67% in 2022. In addition to BIAN, other efforts implemented by Indonesian government contributed to the increase in coverage, including expanding immunization activities to include children aged <5 years and search for unimmunized or partially immunized children in remote and high-risk areas, which are defined on the basis of population immunity, surveillance quality, and the presence of vulnerable groups, such as migratory populations.

Surveillance Activities and Measles and Rubella Incidence

Case-based measles and rubella surveillance was initiated in Indonesia in 2008^§§; in 2019, this was transitioned to case-based fever and rash surveillance.^¶¶ The network of WHO-accredited laboratories for measles and rubella expanded from four in 2013 to seven in 2015. During 2018–2022, the discarded nonmeasles and nonrubella rate (NMNR),*** a measure of surveillance sensitivity, approximately tripled, from 1.2 to 3.3 per 100,000 population (Table). The percentage of cases investigated within 48 hours of notification increased from 65% in 2018 to 74% in 2022. In 2022, 86% of suspected cases with adequate specimens were tested in a WHO-accredited laboratory. However, only 43% of specimens were tested within 4 days of receipt by the laboratory, and 70% of laboratory results were submitted to the immunization program within 4 days of specimen receipt, potentially delaying public health action.

Sentinel CRS surveillance was initiated in 13 hospitals in Indonesia in 2015 and was expanded to 22 hospitals in 2022. During 2018–2022, the national reporting rate for suspected CRS cases (a marker of CRS surveillance sensitivity) increased 85% from 1.71 to 3.16 per 10,000 live births. In 2018, among 275 suspected CRS cases, 89 (32%) were laboratory-confirmed, 99 (36%) were clinically confirmed as CRS, and 87 (32%) were discarded. In 2022, among 1,026 suspected CRS cases, 25 (2%) were laboratory-confirmed, 148 (14%) were clinically confirmed, and 853 (83%) were discarded. Despite the increase in the number of suspected cases, likely related to increased detection through increased surveillance sites, the percentage of laboratory or clinically confirmed CRS cases decreased, likely representing a decline in CRS incidence following introduction of RCV.

During 2013–2022, measles incidence decreased from 33.2 cases per million population to a low of 1.4 in 2021 but sharply increased to 28.8 in 2022 (Table). In 2022, 88% of patients with laboratory-confirmed or epidemiologically linked measles had received no MCV doses or had an unknown vaccination history. After the introduction of RCV and a wide age-range MRCV SIA, rubella incidence declined from 9.3 cases per million in 2013 to a low of 0.6 in 2020 but increased to 3.1 in 2022. Similar to what was observed with measles surveillance, 72% of persons with laboratory-confirmed or epidemiologically linked rubella had received no RCV doses or had unknown vaccination history.

Measles virus genotypes detected and reported included D8 in 2018 and 2022 and B3 in 2022. No rubella virus genotypes were detected or reported (Table).