Pediatric Infectious Disease Research Center, Tehran University of Medical Sciences, Tehran, Iran.
Department of Infectious Diseases, Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran.
Vaccine. 2024 Oct 3;42(23):126243. doi: 10.1016/j.vaccine.2024.126243. Epub 2024 Aug 20.
Measles vaccination has greatly reduced the disease burden worldwide, but challenges remain due to variations in vaccine effectiveness across age groups. This study aimed to assess the serological profile of measles antibodies across different age groups, evaluate the impact of maternal immunity on antibody levels in infants under 12 months, and assess measles immunity in vaccinated individuals.
This cross-sectional study was conducted from June 2022 to January 2023 at the Children's Medical Center, a referral hospital in Iran. Serum samples were tested for measles-specific IgG and IgM antibodies using a commercial enzyme-linked immunosorbent assay (ELSA). An avidity assay was performed to assess measles virus-specific IgG antibodies on the samples that were positive and borderline for the measles IgG ELISA.
The study included 969 participants across various age groups. Among them, 23% (221 out of 953) tested positive for measles IgM ELISA, and 52% (504 out of 969) for measles IgG ELISA. Regarding the avidity assay for measles virus-specific IgG, the majority (418 out of 573, 73%) showed high-avidity antibodies. Measles-specific IgG levels varied significantly across different age groups, with infants below 6 months old showing a mean IgG level of 477 mIU/mL, declining to 230 mIU/mL between 6 and 12 months, and increasing significantly to 683 mIU/mL in the 12 to 18 month age group, reaching a peak at 938 mIU/mL among children aged 18-72 months.
The increasing IgM positivity among young Iranians suggests a rising risk of measles outbreaks, possibly due to vaccination gaps. Inadequate antibody levels in infants raise concerns about vaccination effectiveness. Considering declining maternal antibodies, vaccinating infants at 6-9 months could be beneficial. Boosters for adolescents and women may further mitigate outbreak risks.
麻疹疫苗的接种大大降低了全球的疾病负担，但由于不同年龄组疫苗效力的差异，仍存在挑战。本研究旨在评估不同年龄组麻疹抗体的血清学特征，评估母传抗体对 12 个月以下婴儿抗体水平的影响，并评估已接种人群的麻疹免疫力。
这是一项 2022 年 6 月至 2023 年 1 月在伊朗转诊医院儿童医疗中心进行的横断面研究。使用商业酶联免疫吸附试验（ELISA）检测血清样本中的麻疹特异性 IgG 和 IgM 抗体。对 ELISA 阳性和弱阳性的样本进行麻疹病毒特异性 IgG 抗体亲和力检测。
该研究纳入了来自不同年龄组的 969 名参与者。其中，23%（221 名）的麻疹 IgM ELISA 检测结果为阳性，52%（504 名）的麻疹 IgG ELISA 检测结果为阳性。关于麻疹病毒特异性 IgG 亲和力检测，大多数（418 名）表现出高亲和力抗体。不同年龄组的麻疹特异性 IgG 水平差异显著，6 个月以下婴儿的平均 IgG 水平为 477 mIU/mL，6-12 个月时降至 230 mIU/mL，12-18 个月时显著增加至 683 mIU/mL，18-72 个月时达到峰值 938 mIU/mL。
越来越多的年轻伊朗人 IgM 呈阳性，表明麻疹爆发的风险增加，这可能是由于疫苗接种的差距。婴儿抗体水平不足令人担忧疫苗的有效性。考虑到母传抗体的下降，在 6-9 个月时为婴儿接种疫苗可能会有所帮助。为青少年和妇女接种加强针可能会进一步降低爆发风险。
