Saffar Hana, Khalifeloo Maryam, Saffar Mohammad-Jafar, Abdollahi Alireza, Parsaei Mohammad-Reza, Ghorbani Gholam-Reza, Salarvand Samaneh, Aarabi Mohsen
Department of Pathology, School of medicine, IKHC, Teheran University of Medical Sciences, Tehran, Iran.
Pediatric Infectious Diseases Research Center, communicable Diseases Institute, and Department of Pediatric Infectious Diseases, Bu-Ali Sina Hospital, Mazandaran University of Medical Sciences, Pasdaran Bolv, Sari, Iran.
BMC Infect Dis. 2021 Mar 25;21(1):305. doi: 10.1186/s12879-021-05970-7.
Iranian children were vaccinated with the scheduled two doses of monovalent measles vaccine (mMV) from 1984. In December 2003, a nationwide campaign of measles-rubella (MR) immunization was established to vaccinate 5-25 year- old individuals. In 2004, the mMV was replaced with measles- mumps- rubella (MMR) vaccine. Despite the high vaccination coverage, the outbreaks of measles still occur in the country. In this Study, the MR immunity status of various age groups, vaccinated with different schedules was investigated, and the immunologic response of seronegative subjects to revaccination was examined.
This cross-sectional study was conducted among 7-33-year-old healthy individuals with a documented history of measles vaccination from November 2017 to June 2018. The subjects were categorized as follows: group A, including 20-33 year-old individuals; vaccinated with 1-2 doses of mMV at ages 9 and 15 months, and revaccinated with MR, group B, including 15-19-year-old individuals, vaccinated with two doses of mMV at 9 and 15 months of age, and received additional dose of MMR upon school entrance, group C, including 11-14 year-old individuals, vaccinated with two-doses of MMR at the ages of 15 months and 6 years, and group D, including 7-10 year-old individuals vaccinated with two-doses of MMR vaccine at the ages 12 and 18 months, respectively. Levels of antimeasles- antirubella IgG antibodies in the collected sera were measured. Also antimeasles- antirubella IgM and IgG of seronegative individuals were reexamined at 4-6 weeks after MMR revaccination. The collected data were analyzed using descriptive statistical methods.
A total of 635 individuals were investigated in this study. Group A, 98; group B, 295; group C, 139; and group D, 103 persons. Overall, 12.3 and 18.4% of the population were seronegative for measles and rubella antibodies. This rate varied greatly between the 4 groups: group A, 0/0-2%; group B,15.2-25.0%; group C,11.5-17.2%; and groupD,14.6-18.4%. After revaccination, 92 and 94.9% of seronegative individuals showed IgG response to measles and rubella vaccines, respectively.
Despite the high coverage rate of M-R containing vaccines, a significant number of vaccinated subjects were seronegative for measles and rubella, possibly because of secondary vaccine failure; this may negatively affect measles-rubella elimination targets in the country. If these findings are confirmed in similar future studies, a more robust regional/national supplementary immunization activity will be considered.
自1984年起，伊朗儿童按计划接种两剂单价麻疹疫苗（mMV）。2003年12月，开展了全国范围的麻疹 - 风疹（MR）免疫接种运动，为5至25岁的人群接种疫苗。2004年，mMV被麻疹 - 腮腺炎 - 风疹（MMR）疫苗取代。尽管疫苗接种覆盖率很高，但该国仍有麻疹疫情爆发。在本研究中，调查了按不同接种程序接种疫苗的各年龄组的MR免疫状况，并检测了血清阴性受试者再次接种后的免疫反应。
本横断面研究于2017年11月至2018年6月在7至33岁有麻疹疫苗接种记录的健康个体中进行。受试者分为以下几组：A组，包括20至33岁的个体，9个月和15个月时接种1至2剂mMV，并接种MR疫苗；B组，包括15至19岁的个体，9个月和15个月时接种两剂mMV，并在入学时额外接种一剂MMR；C组，包括11至14岁的个体，15个月和6岁时接种两剂MMR；D组，包括7至10岁的个体，分别在12个月和18个月时接种两剂MMR疫苗。检测所采集血清中抗麻疹 - 抗风疹IgG抗体水平。血清阴性个体在MMR再次接种后4至6周重新检测抗麻疹 - 抗风疹IgM和IgG。使用描述性统计方法分析所收集的数据。
本研究共调查了635名个体。A组98人；B组295人；C组139人；D组103人。总体而言，12.3%和18.4%的人群麻疹和风疹抗体呈血清阴性。该比例在4组之间差异很大：A组为0/0 - 2%；B组为15.2 - 25.0%；C组为11.5 - 17.2%；D组为14.6 - 18.4%。再次接种后，92%和94.9%的血清阴性个体对麻疹和风疹疫苗产生了IgG反应。
尽管含MR疫苗的接种覆盖率很高，但仍有相当数量的接种者麻疹和风疹抗体呈血清阴性，可能是由于继发性疫苗接种失败；这可能对该国麻疹 - 风疹消除目标产生负面影响。如果这些发现在未来类似研究中得到证实，将考虑开展更有力的区域/全国性补充免疫活动。
