Syed Mohamed Ahmed, A/Qotba Hamda Abdulla, Al Nuaimi Ahmed Sameer, Nasrallah Gheyath K, Althani Asmaa Ali J F, Zainel Abduljaleel Abdullatif, Khudadad Hanan, Marji Tamara, Veettil Shajitha Thekke, AlFehaidi AlAnoud Saleh, Yfakhroo Ameena Ibrahim, AlMesaifri Meshal Abdulla, Al-Baghdadi Tholfakhar Talib, Al Mujalli Hanan, Al Abdulla Samya Ahmad, Abdulmalik Mariam Ali
Department of Clinical Research, Primary Health Care Corporation, Doha, Qatar.
Biomedical Research Centre, Qatar University, Doha, Qatar.
J Prim Care Community Health. 2021 Jan-Dec;12:21501327211050569. doi: 10.1177/21501327211050569.
Globally, countries are rolling out Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) quarantine policies and vaccination programs. Research studies are needed in helping understand the likelihood of acquired immunity to reinfection and identify priority groups for vaccination to inform them. This study aimed to assess period prevalence and longitudinal changes in antibody levels after SARS-CoV-2 infection in Qatari primary care settings.
A cohort study design with 2 data collection phases was undertaken-Phase 1 (conducted in July 2020) and Phase 2 (conducted in October 2020). A stratified random sampling technique by age, gender and nationality was utilized to identify the study sample. The total sample size required for the study was estimated to be 2102. Participants were invited to an appointment where they were administered a questionnaire and provided samples for polymerase chain reaction and Immunoglobulin G immunoassay tests.
A total of 943 individuals participated in both Phase 1 and Phase 2. In this cohort, seroprevalence of SARS-CoV-2 was found to be 12% (N = 113) in Phase 1 and 17.2% (N = 162) in Phase 2. Of the 113 participants who were seropositive in Phase 1, 38.1% (CI 29.5-47.2%, N = 43) had a reduction, 54.9% (CI 45.7-63.8%, N = 62) had no change, and 7.1% (CI 3.4-12.9%, N = 8) had an increase in IgG titer in Phase 2. All (N = 18) participants aged 10 to 17 years retained their antibodies. The proportion of men who retained their antibodies was slightly higher compared to women-92.5% (N = 74) and 87.9% (N = 29) respectively. Similarly, symptomatic individuals (97.8%; N = 45) had a higher antibody retention compared with asymptomatic individuals (86.4%; N = 57).
This study provides preliminary information on the longitudinal changes in antibody levels after SARS-CoV-2 infection. These findings will help inform quarantine policies and vaccination programs.
在全球范围内，各国正在推行严重急性呼吸综合征冠状病毒2（SARS-CoV-2）检疫政策和疫苗接种计划。需要开展研究以帮助了解获得性免疫对再次感染的可能性，并确定疫苗接种的优先群体，为其提供信息。本研究旨在评估卡塔尔初级保健机构中SARS-CoV-2感染后抗体水平的期间患病率和纵向变化。
采用队列研究设计，分两个数据收集阶段进行——第一阶段（于2020年7月开展）和第二阶段（于2020年10月开展）。利用按年龄、性别和国籍分层的随机抽样技术确定研究样本。估计该研究所需的总样本量为2102。邀请参与者前来接受问卷调查，并提供样本进行聚合酶链反应和免疫球蛋白G免疫测定试验。
共有943人参与了第一阶段和第二阶段。在这个队列中，SARS-CoV-2的血清阳性率在第一阶段为12%（N = 113），在第二阶段为17.2%（N = 162）。在第一阶段血清呈阳性的113名参与者中，38.1%（置信区间29.5 - 47.2%，N = 43）的免疫球蛋白G滴度下降，54.9%（置信区间45.7 - 63.8%，N = 62）无变化，7.1%（置信区间3.4 - 12.9%，N = 8）上升。所有10至17岁的参与者（N = 18）均保留了抗体。保留抗体的男性比例略高于女性，分别为92.5%（N = 74）和87.9%（N = 29）。同样，有症状的个体（97.8%；N = 45）的抗体保留率高于无症状个体（86.4%；N = 57）。
本研究提供了SARS-CoV-2感染后抗体水平纵向变化的初步信息。这些发现将有助于为检疫政策和疫苗接种计划提供信息。
