Prasithsirikul Wisit, Pongpirul Krit, Nopsopon Tanawin, Phutrakool Phanupong, Pongpirul Wannarat, Samuthpongtorn Chatpol, Suwanwattana Pawita, Jongkaewwattana Anan
Bamrasnaradura Infectious Diseases Institute, Nonthaburi 11000, Thailand.
Department of Preventive and Social Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand.
Vaccines (Basel). 2022 Jan 30;10(2):217. doi: 10.3390/vaccines10020217.
During the early phase of the COVID-19 pandemic, several countries, including Thailand, provided two shots of CoronaVac to healthcare workers. Whereas ChAdOx1 nCoV-19 is the promising vaccine as the booster dose, the data on immunogenicity when administered after CoronaVac have been limited. The purpose of this study was to evaluate the immunogenicity of ChAdOx1 nCoV-19 as the third dose vaccine in healthcare workers who previously received two shots of CoronaVac. The blood samples were obtained before the third vaccination dose, and one month and three months after vaccination. All participants were measured for humoral immunity including anti-spike IgG and neutralizing antibody by ELISA. Twenty participants were stratified by random samples based on baseline IgG status for a cellular immunity function test at three-month post-vaccination, which included T cell and B cell functions by ELISpot. This study showed significant improvement for both humoral and cellular immunity one month after vaccination. Subgroup analysis indicated a significantly higher neutralizing antibody improvement for the population with a negative anti-spike IgG at baseline. Our study suggests that, while immunity level declines at three months post-vaccination, the level was sufficiently high to protect against SARS-CoV-2.
在新冠疫情早期，包括泰国在内的几个国家为医护人员接种了两剂科兴疫苗。虽然腺病毒载体新冠疫苗（ChAdOx1 nCoV-19）作为加强针是一种很有前景的疫苗，但在接种科兴疫苗后再接种该疫苗的免疫原性数据有限。本研究的目的是评估腺病毒载体新冠疫苗（ChAdOx1 nCoV-19）作为第三剂疫苗在先前已接种两剂科兴疫苗的医护人员中的免疫原性。在接种第三剂疫苗前、接种后1个月和3个月采集血样。通过酶联免疫吸附测定法（ELISA）对所有参与者进行体液免疫检测，包括抗刺突蛋白IgG和中和抗体。20名参与者根据基线IgG状态随机分层，在接种疫苗后3个月进行细胞免疫功能检测，包括通过酶联免疫斑点法（ELISpot）检测T细胞和B细胞功能。本研究表明，接种疫苗1个月后体液免疫和细胞免疫均有显著改善。亚组分析表明，基线抗刺突蛋白IgG呈阴性的人群中和抗体改善更为显著。我们的研究表明，虽然接种疫苗3个月后免疫水平有所下降，但该水平仍足以预防新冠病毒。
