Alharbi Naif Khalaf, Al-Tawfiq Jaffar A, Alwehaibe Amal, Alenazi Mohamed W, Almasoud Abdulrahman, Algaisi Abdullah, Alhumaydhi Fahad A, Hashem Anwar M, Bosaeed Mohammed, Alsagaby Suliman A
Vaccine Development Unit, King Abdullah International Medical Research Center (KAIMRC), Riyadh, Saudi Arabia.
College of Medicine, King Saud bin Abdulaziz University for Health Science (KSAU-HS), Riyadh, Saudi Arabia.
Infect Drug Resist. 2022 Jul 29;15:4127-4136. doi: 10.2147/IDR.S362848. eCollection 2022.
This study was conducted to investigate antibody immune responses induced by BNT162b2 and AZD1222 human COVID-19 vaccines in Riyadh city, Saudi Arabia.
ELISA was used to evaluate antibodies, against the SARS-CoV-2 spike S1 protein, in serum samples from 432 vaccinated individuals at six time points: pre-vaccination (baseline), post-prime, post-boost, 6-months, and 1 year post-vaccination, and 3 weeks post a third dose. Virus microneutralization assay was used to confirm antibody responses in a subset of samples.
Anti-SARS-CoV-2 spike IgG were detected in most subjects post-prime, reached a peak level post-boost, and remained at high level at the 6-month follow-up. At 1 year post-vaccine, the antibody levels were low but increased to a significant level higher than the peak following a third dose. The third dose was given at an average of 250 days after the second dose. The virus microneutralization assay confirmed the neutralization activity of the induced SARS-CoV-2 IgG antibodies. The vaccines induced higher IgG titres at post-prime (=0.0001) and 6 months (=0.006) in previously infected individuals. An increased interval between prime and boost, more than recommended time, appeared to enhance the IgG levels (=0004). Moreover, the vaccines induced higher IgG levels in younger subjects (=0.01).
These data provide insights and build on the current understanding of immune responses induced by these two vaccines; and support a third boosting dose for these COVID-19 vaccines.
本研究旨在调查沙特阿拉伯利雅得市BNT162b2和AZD1222两种新冠疫苗诱导的抗体免疫反应。
采用酶联免疫吸附测定法（ELISA），在六个时间点评估432名接种疫苗个体血清样本中针对严重急性呼吸综合征冠状病毒2（SARS-CoV-2）刺突S1蛋白的抗体，这六个时间点分别为：接种前（基线）、初次接种后、加强接种后、接种后6个月、接种后1年以及第三剂接种后3周。采用病毒微量中和试验在一部分样本中确认抗体反应。
大多数受试者在初次接种后检测到抗SARS-CoV-2刺突IgG，在加强接种后达到峰值水平，并在6个月随访时维持在高水平。接种疫苗1年后，抗体水平较低，但在第三剂接种后升高至显著高于峰值的水平。第三剂平均在第二剂接种后250天给予。病毒微量中和试验证实了诱导产生的SARS-CoV-2 IgG抗体的中和活性。这两种疫苗在既往感染个体的初次接种后（=0.0001）和6个月时（=0.006）诱导产生更高的IgG滴度。初次接种和加强接种之间的间隔时间延长（超过推荐时间）似乎会提高IgG水平（=0.004）。此外，这两种疫苗在较年轻受试者中诱导产生更高的IgG水平（=0.01）。
这些数据为这两种疫苗诱导的免疫反应提供了见解，并基于当前的理解进行了拓展；支持为这些新冠疫苗接种第三剂加强针。
