Klinmalai Chompunuch, Srisala Supanart, Sahakijpicharn Thiantip, Apiwattanakul Nopporn
Department of Paediatrics, Faculty of Medicine Ramathibodi Hospital Mahidol University Bangkok Thailand.
Research Center, Faculty of Medicine Ramathibodi Hospital Mahidol University Bangkok Thailand.
Health Sci Rep. 2024 Jul 16;7(7):e2250. doi: 10.1002/hsr2.2250. eCollection 2024 Jul.
Coronavirus disease 2019 (COVID-19) has become a global pandemic and led to increased mortality and morbidity. Vaccines against the etiologic agent; severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) were approved for emergency use on different platforms. In the early phase of the pandemic, Thai healthcare workers (HCWs) received CoronaVac, an inactivated vaccine, as the first vaccine against SARS-CoV-2, followed by ChAdOx1 nCoV-19, a viral vector-based vaccine, or BNT162b2, an mRNA vaccine, as a booster dose. This preliminary study evaluated the immunogenicity of ChAdOx1 nCoV-19 and BNT162b2 as a booster dose in HCWs who previously received two doses of CoronaVac.
Ten HCW participants received ChAdOx1 nCoV-19 and another 10 HCWs received BNT162b2 as a booster dose after two doses of CoronaVac. Anti-RBD IgG, neutralizing antibodies (NAb), and cellular immunity, including interferon-gamma (IFN-γ)-releasing CD4, CD8, double negative T cells, and NK cells, were measured at 3 and 5 months after the booster dose.
There was no significant difference in anti-RBD IgG levels at 3 and 5 months between the two different types of booster vaccine. The levels of anti-RBD IgG and NAb were significantly decreased at 5 months. HCWs receiving BNT162b2 had significantly higher NAb levels than those receiving ChAdOx1 nCoV-19 at 5 months after the booster dose. IFN-γ release from CD4 T cells was detected at 3 months with no significant difference between the two types of booster vaccines. However, IFN-γ-releasing CD4 T cells were present at 5 months in the ChAdOx1 nCoV-19 group only.
ChAdOx1 nCoV-19 or BNT162b2 can be used as a booster dose after completion of the primary series primed by inactivated vaccine. Although the levels of immunity decline at 5 months, they may be adequate during the first 3 months after the booster dose.
2019冠状病毒病（COVID-19）已成为全球大流行疾病，导致死亡率和发病率上升。针对病原体严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的疫苗已在不同平台获批紧急使用。在疫情早期，泰国医护人员（HCWs）接种了第一剂针对SARS-CoV-2的疫苗——科兴新冠灭活疫苗（CoronaVac），随后接种了基于病毒载体的疫苗ChAdOx1 nCoV-19或mRNA疫苗BNT162b2作为加强针。这项初步研究评估了ChAdOx1 nCoV-19和BNT162b2作为加强针在先前接种两剂科兴新冠灭活疫苗的医护人员中的免疫原性。
10名医护人员参与者在接种两剂科兴新冠灭活疫苗后接种ChAdOx1 nCoV-19作为加强针，另外10名医护人员接种BNT162b2作为加强针。在加强针接种后3个月和5个月测量抗受体结合域（RBD）IgG、中和抗体（NAb）以及细胞免疫，包括释放γ干扰素（IFN-γ）的CD4、CD8、双阴性T细胞和自然杀伤（NK）细胞。
两种不同类型的加强针疫苗在接种后3个月和5个月时抗RBD IgG水平无显著差异。抗RBD IgG和NAb水平在5个月时显著下降。接种BNT162b2的医护人员在加强针接种后5个月时的NAb水平显著高于接种ChAdOx1 nCoV-19的医护人员。在3个月时检测到CD4 T细胞释放IFN-γ，两种类型的加强针疫苗之间无显著差异。然而，仅在ChAdOx1 nCoV-19组中5个月时存在释放IFN-γ的CD4 T细胞。
ChAdOx1 nCoV-19或BNT162b2可在灭活疫苗完成初始接种系列后用作加强针。尽管免疫水平在5个月时下降，但在加强针接种后的前3个月可能足够。
