Quach Huy Quang, Jones Sara P, Joseph Iype, Powell Alexandria J, Ovsyannikova Inna G, Warner Nathaniel D, Grill Diane E, Johnson John B, Sasi Remya Vasanthi, Ajithakumari Archana Mohankumar, Prasad Raji, Reveendran Remya, Devakikutty Jayalekshmi, Mohanakumari Vishnu Vikraman, Poland Gregory A, Pillai M Radhakrishna, Jacob Joshy, Kennedy Richard B
Mayo Clinic Vaccine Research Group, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota.
Pathogen Biology, BRIC-Rajiv Gandhi Centre for Biotechnology (BRIC-RGCB), Jagathy, Thiruvananthapuram 695014, Kerala, India.
JAMA Netw Open. 2025 Aug 1;8(8):e2529409. doi: 10.1001/jamanetworkopen.2025.29409.
India's goal of measles elimination remains unmet, as evidenced by significant recent outbreaks.
To identify seroprevalence rates among vaccinated children and to examine demographic factors that influence antibody responses.
DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study included a highly vaccinated cohort of Indian children from the states of Kerala and Tamil Nadu between 2018 and 2023. Eligible children had received at least 2 doses of measles-containing vaccines; their mothers were recruited from various community settings, including local nursery and secondary schools, residential associations, and hospitals.
Measles-specific antibodies were quantified in serum samples.
Measles-specific immunoglobulin G (IgG) and neutralizing antibodies were quantified in both children and mothers. Measles-specific IgM was also measured in children.
The total cohort comprised 684 children (median age, 9 years [range, 4-18 years]; 348 male [50.1%]) and 544 mothers. All children received at least 2 doses of measles-containing vaccines; 435 children (63.6%) received a third dose, and 7 (1.0%) received a fourth dose. Among the children, 621 (90.8%) had positive measles-specific IgG, and 623 (91.5%) had protective neutralizing antibodies titers, with a strong correlation between measles-specific IgG and neutralizing antibodies (r = 0.73; P < .001). Female children exhibited significantly higher titers of both measles-specific IgG and neutralizing antibodies compared with male children. While IgG and neutralizing antibody titers remained stable over time and were not associated with the number of vaccine doses in children, neutralizing antibody titers increased with age in mothers, likely due to repeated viral exposure. Notably, in 20 families with at least 2 children, differential measles-specific IgM profiles were observed between siblings despite high IgG and neutralizing antibody titers, suggesting ongoing breakthrough infections.
In this cross-sectional study, substantial measles immunity gaps were found despite high vaccine coverage with evidence of breakthrough infections, posing significant challenges to India's measles elimination efforts. These results underscore the urgent need to strengthen India's immunization program and investigate the mechanisms driving suboptimal responses to measles vaccination; without addressing these immune response deficiencies, achieving measles elimination through increased vaccine coverage alone may remain unattainable in India.
印度消除麻疹的目标仍未实现，近期的大规模疫情就是明证。
确定接种疫苗儿童的血清阳性率，并研究影响抗体反应的人口统计学因素。
设计、背景和参与者：这项横断面研究纳入了2018年至2023年间来自喀拉拉邦和泰米尔纳德邦的一群高接种率的印度儿童。符合条件的儿童至少接种了2剂含麻疹疫苗；他们的母亲是从各种社区环境中招募的，包括当地托儿所、中学、居民协会和医院。
对血清样本中的麻疹特异性抗体进行定量。
对儿童和母亲的麻疹特异性免疫球蛋白G（IgG）和中和抗体进行定量。还对儿童测量了麻疹特异性IgM。
总队列包括684名儿童（中位年龄9岁[范围4 - 18岁]；348名男性[50.1%]）和544名母亲。所有儿童至少接种了2剂含麻疹疫苗；435名儿童（63.6%）接种了第三剂，7名儿童（1.0%）接种了第四剂。在儿童中，621名（90.8%）有阳性麻疹特异性IgG，623名（91.5%）有保护性中和抗体滴度，麻疹特异性IgG与中和抗体之间有很强的相关性（r = 0.73；P < 0.001）。与男性儿童相比，女性儿童的麻疹特异性IgG和中和抗体滴度均显著更高。虽然儿童的IgG和中和抗体滴度随时间保持稳定，且与疫苗接种剂量无关，但母亲的中和抗体滴度随年龄增加，可能是由于反复接触病毒。值得注意的是，在至少有2名儿童的20个家庭中，尽管IgG和中和抗体滴度较高，但兄弟姐妹之间仍观察到不同的麻疹特异性IgM谱，提示存在持续的突破性感染。
在这项横断面研究中，尽管疫苗接种覆盖率很高，但仍发现了大量麻疹免疫差距，并有突破性感染的证据，这给印度的麻疹消除工作带来了重大挑战。这些结果强调了迫切需要加强印度的免疫规划，并调查导致对麻疹疫苗反应欠佳的机制；如果不解决这些免疫反应缺陷问题，仅通过提高疫苗接种覆盖率在印度实现消除麻疹可能仍然无法实现。
