Bhuiyan Taufiqur Rahman, Akhtar Marjahan, Khaton Fatema, Rahman Sadia Isfat Ara, Ferdous Jannatul, Alamgir A S M, Rahman Mahbubur, Kawser Zannat, Hasan Imrul, Calderwood Stephen Beaven, Harris Jason B, Charles Richelle C, LaRocque Regina C, Ryan Edward Thomas, Banu Sayera, Shirin Tahmina, Qadri Firdausi
International Centre for Diarrhoeal Disease Research Bangladesh, Dhaka, Bangladesh.
Institute of Epidemiology, Disease Control and Research, Dhaka, Bangladesh.
IJID Reg. 2022 Jun;3:211-217. doi: 10.1016/j.ijregi.2022.04.006. Epub 2022 Apr 29.
To evaluate severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-specific antibody responses after Covishield vaccination for 6 months after vaccination.
SARS-CoV-2-specific antibody responses were assessed by enzyme-linked immunosorbent assay of the recombinant receptor-binding domain of SARS-CoV-2 in 381 adults given the Covishield vaccine at baseline (=119), 1 month (=126) and 2 months (=75) after the first dose, 1 month after the second dose (=161), and monthly for 3 additional months.
Over 51% of participants were seropositive at baseline (before vaccination with Covishield), and almost all participants (159/161) became seropositive 1 month after the second dose. Antibody levels peaked 1 month after receipt of the second dose of vaccine, and decreased by 4 months after the first dose; the lowest responses were found 6 months after the first dose, although antibody responses and responder frequencies remained significantly higher compared with baseline (<0.0001). Compared with younger participants, older participants had lower antibody responses 6 months after the first dose of vaccine (<0.05). Participants who had previous SARS-CoV-2 infection showed robust higher antibody responses after vaccination.
These findings help to elucidate the longevity of vaccine-specific antibody responses following vaccination with Covishield, and provide information relevant to the planning of booster doses after the initial two doses of vaccine.
评估接种Covishield疫苗6个月后严重急性呼吸综合征冠状病毒2（SARS-CoV-2）特异性抗体反应。
通过酶联免疫吸附测定法，对381名成年人接种Covishield疫苗后基线（=119）、首剂后1个月（=126）、2个月（=75）、第二剂后1个月（=161）以及随后3个月每月的SARS-CoV-2重组受体结合域特异性抗体反应进行评估。
超过51%的参与者在基线时（接种Covishield疫苗前）血清呈阳性，几乎所有参与者（159/161）在第二剂后1个月血清转为阳性。抗体水平在接种第二剂疫苗后1个月达到峰值，在首剂后4个月下降；首剂后6个月反应最低，尽管抗体反应和反应者频率仍显著高于基线（<0.0001）。与年轻参与者相比，老年参与者在接种首剂疫苗6个月后的抗体反应较低（<0.05）。既往感染过SARS-CoV-2的参与者在接种疫苗后抗体反应更强。
这些发现有助于阐明接种Covishield疫苗后疫苗特异性抗体反应的持续时间，并为规划初始两剂疫苗后的加强剂量提供相关信息。
