Gelanew Tesfaye, Mulu Andargachew, Abebe Markos, Bates Timothy A, Wassie Liya, Teferi Mekonnen, Fentahun Dessalegn, Alemu Aynalem, Tamiru Frehiwot, Assefa Gebeyehu, Bayih Abebe Genetu, Tafesse Fikadu G, Mihret Adane, Abdissa Alemseged
Armauer Hansen Research Institute, Jimma Road, ALERT Campus, Addis Ababa P.O. Box 1005, Ethiopia.
Department of Molecular Microbiology & Immunology, Oregon Health & Sciences University (OHSU), Portland, OR 97239, USA.
Vaccines (Basel). 2022 May 27;10(6):859. doi: 10.3390/vaccines10060859.
Single-dose COVID-19 vaccines, mostly mRNA-based vaccines, are shown to induce robust antibody responses in individuals who were previously infected with SARS-CoV-2, suggesting the sufficiency of a single dose for those individuals in countries with limited vaccine supply. However, these important data are limited to developed nations. We conducted a prospective longitudinal study among Ethiopian healthcare workers who received a ChAdOx1 nCoV-19 vaccine. We compared the geometric mean titers (GMTs) of the SARS-CoV-2 receptor-binding domain (RBD)-specific IgG antibodies in 39 SARS-CoV-2 naïve participants and 24 participants previously infected with SARS-CoV-2 (P.I.), who received two doses of ChAdOx1 nCoV-19 vaccine across the two post-vaccination time points (at 8 to 12 weeks post single dose and two dose vaccinations). We noted that the GMT (1632.16) in naïve participants at 8-12 weeks post first dose were comparable to the GMT (1674.94) observed in P.I. participants prior to vaccination. Interestingly, P.I. participants had significantly higher antibody titers compared to naïve participants, after both the first (GMT, 4913.50 vs. 1632.16) and second doses (GMT, 9804.60 vs. 6607.30). Taken together, our findings show that a single ChAdOx1 nCoV-19 dose in previously SARS-CoV-2 infected individuals elicits similar, if not higher, antibody responses to those of two-dose-vaccinated naïve individuals.
单剂量新冠疫苗（大多为基于信使核糖核酸的疫苗）已显示可在先前感染过严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的个体中诱导强烈的抗体反应，这表明在疫苗供应有限的国家，单剂量疫苗对这些个体来说已足够。然而，这些重要数据仅限于发达国家。我们对接受了ChAdOx1 nCoV-19疫苗的埃塞俄比亚医护人员进行了一项前瞻性纵向研究。我们比较了39名未感染过SARS-CoV-2的参与者和24名先前感染过SARS-CoV-2（P.I.）的参与者中，针对SARS-CoV-2受体结合域（RBD）的特异性免疫球蛋白G（IgG）抗体的几何平均滴度（GMTs），这些参与者在两个疫苗接种后的时间点（单剂量接种后8至12周以及两剂接种后）接受了两剂ChAdOx1 nCoV-19疫苗。我们注意到，首次接种后8至12周时，未感染过SARS-CoV-2的参与者的GMT（1632.16）与接种疫苗前P.I.参与者中观察到的GMT（1674.94）相当。有趣的是，在第一剂（GMT，4913.50对1632.16）和第二剂（GMT，9804.60对6607.30）接种后，P.I.参与者的抗体滴度显著高于未感染过SARS-CoV-2的参与者。综上所述，我们的研究结果表明，在先前感染过SARS-CoV-2的个体中，单剂ChAdOx1 nCoV-19疫苗引发的抗体反应即便不比接种两剂疫苗的未感染过SARS-CoV-2的个体更高，也与之相似。
