Abstract：
BACKGROUND: India aims to eliminate rubella and congenital rubella syndrome (CRS) by 2023. We conducted serosurveys among pregnant women to monitor the trend of rubella immunity and estimate the CRS burden in India following a nationwide measles and rubella vaccination campaign.
METHODS: We surveyed pregnant women at 13 sentinel sites across India from Aug to Oct 2022 to estimate seroprevalence of rubella IgG antibodies. Using age-specific seroprevalence data from serosurveys conducted during 2017/2019 (prior to and during the vaccination campaign) and 2022 surveys (after the vaccination campaign), we developed force of infection (FOI) models and estimated incidence and burden of CRS.
RESULTS: In 2022, rubella seroprevalence was 85.2% (95% CI: 84.0, 86.2). Among 10 sites which participated in both rounds of serosurveys, the seroprevalence was not different between the two periods (pooled prevalence during 2017/2019: 83.5%, 95% CI: 82.1, 84.8; prevalence during 2022: 85.1%, 95% CI: 83.8, 86.3). The estimated annual incidence of CRS during 2017/2019 in India was 218.3 (95% CI: 209.7, 226.5) per 100, 000 livebirths, resulting in 47,120 (95% CI: 45,260, 48,875) cases of CRS every year. After measles-rubella (MR) vaccination campaign, the estimated incidence of CRS declined to 5.3 (95% CI: 0, 21.2) per 100,000 livebirths, resulting in 1141 (95% CI: 0, 4,569) cases of CRS during the post MR-vaccination campaign period.
CONCLUSIONS: The incidence of CRS in India has substantially decreased following the nationwide MR vaccination campaign. About 15% of women in childbearing age in India lack immunity to rubella and hence susceptible to rubella infection. Since there are no routine rubella vaccination opportunities for this age group under the national immunization program, it is imperative to maintain high rates of rubella vaccination among children to prevent rubella virus exposure among women of childbearing age susceptible for rubella.
METHODS: We surveyed pregnant women at 13 sentinel sites across India from Aug to Oct 2022 to estimate seroprevalence of rubella IgG antibodies. Using age-specific seroprevalence data from serosurveys conducted during 2017/2019 (prior to and during the vaccination campaign) and 2022 surveys (after the vaccination campaign), we developed force of infection (FOI) models and estimated incidence and burden of CRS.
RESULTS: In 2022, rubella seroprevalence was 85.2% (95% CI: 84.0, 86.2). Among 10 sites which participated in both rounds of serosurveys, the seroprevalence was not different between the two periods (pooled prevalence during 2017/2019: 83.5%, 95% CI: 82.1, 84.8; prevalence during 2022: 85.1%, 95% CI: 83.8, 86.3). The estimated annual incidence of CRS during 2017/2019 in India was 218.3 (95% CI: 209.7, 226.5) per 100, 000 livebirths, resulting in 47,120 (95% CI: 45,260, 48,875) cases of CRS every year. After measles-rubella (MR) vaccination campaign, the estimated incidence of CRS declined to 5.3 (95% CI: 0, 21.2) per 100,000 livebirths, resulting in 1141 (95% CI: 0, 4,569) cases of CRS during the post MR-vaccination campaign period.
CONCLUSIONS: The incidence of CRS in India has substantially decreased following the nationwide MR vaccination campaign. About 15% of women in childbearing age in India lack immunity to rubella and hence susceptible to rubella infection. Since there are no routine rubella vaccination opportunities for this age group under the national immunization program, it is imperative to maintain high rates of rubella vaccination among children to prevent rubella virus exposure among women of childbearing age susceptible for rubella.
摘要：
背景：印度的目标是到2023年消除风疹和先天性风疹综合征（CRS）。我们对孕妇进行了血清调查，以监测风疹免疫趋势，并在全国范围内开展麻疹和风疹疫苗接种运动后估计印度的CRS负担。
方法：我们从2022年8月至10月调查了印度13个前哨地点的孕妇，以估计风疹IgG抗体的血清阳性率。使用2017/2019年（疫苗接种运动之前和期间）和2022年调查（疫苗接种运动之后）进行的血清调查的年龄特异性血清阳性率数据，我们建立了感染力(FOI)模型,并估计了CRS的发病率和负担.
结果：2022年，风疹血清阳性率为85.2％（95％CI：84.0，86.2）。在参与两轮血清调查的10个地点中，两个时期的血清阳性率没有差异(2017/2019年的合并患病率：83.5%，95%CI：82.1，84.8；2022年患病率：85.1%，95%CI：83.8，86.3）。2017/2019年期间，印度CRS的估计年发病率为每100,000例新生儿218.3（95％CI：209.7，226.5），每年导致47,120例(95%CI：45,260,48,875例)CRS病例。麻疹-风疹（MR）疫苗接种运动后，CRS的估计发病率下降到每100,000例新生儿5.3例(95%CI:0,21.2)，在MR疫苗接种后运动期间，导致1141例(95%CI:0,4,569例)CRS病例。
结论：在全国范围内的MR疫苗接种运动之后，印度的CRS发病率大幅下降。印度大约15%的育龄妇女缺乏对风疹的免疫力，因此容易感染风疹。由于在国家免疫计划下，该年龄组没有常规的风疹疫苗接种机会，必须在儿童中保持较高的风疹疫苗接种率，以防止风疹易感的育龄妇女接触风疹病毒。
方法：我们从2022年8月至10月调查了印度13个前哨地点的孕妇，以估计风疹IgG抗体的血清阳性率。使用2017/2019年（疫苗接种运动之前和期间）和2022年调查（疫苗接种运动之后）进行的血清调查的年龄特异性血清阳性率数据，我们建立了感染力(FOI)模型,并估计了CRS的发病率和负担.
结果：2022年，风疹血清阳性率为85.2％（95％CI：84.0，86.2）。在参与两轮血清调查的10个地点中，两个时期的血清阳性率没有差异(2017/2019年的合并患病率：83.5%，95%CI：82.1，84.8；2022年患病率：85.1%，95%CI：83.8，86.3）。2017/2019年期间，印度CRS的估计年发病率为每100,000例新生儿218.3（95％CI：209.7，226.5），每年导致47,120例(95%CI：45,260,48,875例)CRS病例。麻疹-风疹（MR）疫苗接种运动后，CRS的估计发病率下降到每100,000例新生儿5.3例(95%CI:0,21.2)，在MR疫苗接种后运动期间，导致1141例(95%CI:0,4,569例)CRS病例。
结论：在全国范围内的MR疫苗接种运动之后，印度的CRS发病率大幅下降。印度大约15%的育龄妇女缺乏对风疹的免疫力，因此容易感染风疹。由于在国家免疫计划下，该年龄组没有常规的风疹疫苗接种机会，必须在儿童中保持较高的风疹疫苗接种率，以防止风疹易感的育龄妇女接触风疹病毒。
