PDF(Pubmed)
Abstract：
BACKGROUND: The durability of heterologous COVID-19 vaccine effectiveness (VE) has been primarily studied in high-income countries, while evaluation of heterologous vaccine policies in low- and middle-income countries remains limited.
OBJECTIVE: We aimed to evaluate the duration during which the VE of heterologous COVID-19 vaccine regimens in mitigating serious outcomes, specifically severe COVID-19 and death following hospitalization with COVID-19, remains over 50%.
METHODS: We formed a dynamic cohort by linking records of Thai citizens aged ≥18 years from citizen vital, COVID-19 vaccine, and COVID-19 cases registry databases between May 2021 and July 2022. Encrypted citizen identification numbers were used to merge the data between the databases. This study focuses on 8 common heterologous vaccine sequences: CoronaVac/ChAdOx1, ChAdOx1/BNT162b2, CoronaVac/CoronaVac/ChAdOx1, CoronaVac/ChAdOx1/ChAdOx1, CoronaVac/ChAdOx1/BNT162b2, BBIBP-CorV/BBIBP-CorV/BNT162b2, ChAdOx1/ChAdOx1/BNT162b2, and ChAdOx1/ChAdOx1/mRNA-1273. Nonimmunized individuals were considered for comparisons. The cohort was stratified according to the vaccination status, age, sex, province location, month of vaccination, and outcome. Data analysis employed logistic regression to determine the VE, accounting for potential confounders and durability over time, with data observed over a follow-up period of 7 months.
RESULTS: This study includes 52,580,841 individuals, with approximately 17,907,215 and 17,190,975 receiving 2- and 3-dose common heterologous vaccines (not mutually exclusive), respectively. The 2-dose heterologous vaccinations offered approximately 50% VE against severe COVID-19 and death following hospitalization with COVID-19 for 2 months; however, the protection significantly declined over time. The 3-dose heterologous vaccinations sustained over 50% VE against both outcomes for at least 8 months, as determined by logistic regression with durability time-interaction modeling. The vaccine sequence consisting of CoronaVac/CoronaVac/ChAdOx1 demonstrated >80% VE against both outcomes, with no evidence of VE waning. The final monthly measured VE of CoronaVac/CoronaVac/ChAdOx1 against severe COVID-19 and death following hospitalization at 7 months after the last dose was 82% (95% CI 80.3%-84%) and 86.3% (95% CI 83.6%-84%), respectively.
CONCLUSIONS: In Thailand, within a 7-month observation period, the 2-dose regimens could not maintain a 50% VE against severe and fatal COVID-19 for over 2 months, but all of the 3-dose regimens did. The CoronaVac/CoronaVac/ChAdOx1 regimen showed the best protective effect against severe and fatal COVID-19. The estimated durability of 50% VE for at least 8 months across all 3-dose heterologous COVID-19 vaccine regimens supports the adoption of heterologous prime-boost vaccination strategies, with a primary series of inactivated virus vaccine and boosting with either a viral vector or an mRNA vaccine, to prevent similar pandemics in low- and middle-income countries.
OBJECTIVE: We aimed to evaluate the duration during which the VE of heterologous COVID-19 vaccine regimens in mitigating serious outcomes, specifically severe COVID-19 and death following hospitalization with COVID-19, remains over 50%.
METHODS: We formed a dynamic cohort by linking records of Thai citizens aged ≥18 years from citizen vital, COVID-19 vaccine, and COVID-19 cases registry databases between May 2021 and July 2022. Encrypted citizen identification numbers were used to merge the data between the databases. This study focuses on 8 common heterologous vaccine sequences: CoronaVac/ChAdOx1, ChAdOx1/BNT162b2, CoronaVac/CoronaVac/ChAdOx1, CoronaVac/ChAdOx1/ChAdOx1, CoronaVac/ChAdOx1/BNT162b2, BBIBP-CorV/BBIBP-CorV/BNT162b2, ChAdOx1/ChAdOx1/BNT162b2, and ChAdOx1/ChAdOx1/mRNA-1273. Nonimmunized individuals were considered for comparisons. The cohort was stratified according to the vaccination status, age, sex, province location, month of vaccination, and outcome. Data analysis employed logistic regression to determine the VE, accounting for potential confounders and durability over time, with data observed over a follow-up period of 7 months.
RESULTS: This study includes 52,580,841 individuals, with approximately 17,907,215 and 17,190,975 receiving 2- and 3-dose common heterologous vaccines (not mutually exclusive), respectively. The 2-dose heterologous vaccinations offered approximately 50% VE against severe COVID-19 and death following hospitalization with COVID-19 for 2 months; however, the protection significantly declined over time. The 3-dose heterologous vaccinations sustained over 50% VE against both outcomes for at least 8 months, as determined by logistic regression with durability time-interaction modeling. The vaccine sequence consisting of CoronaVac/CoronaVac/ChAdOx1 demonstrated >80% VE against both outcomes, with no evidence of VE waning. The final monthly measured VE of CoronaVac/CoronaVac/ChAdOx1 against severe COVID-19 and death following hospitalization at 7 months after the last dose was 82% (95% CI 80.3%-84%) and 86.3% (95% CI 83.6%-84%), respectively.
CONCLUSIONS: In Thailand, within a 7-month observation period, the 2-dose regimens could not maintain a 50% VE against severe and fatal COVID-19 for over 2 months, but all of the 3-dose regimens did. The CoronaVac/CoronaVac/ChAdOx1 regimen showed the best protective effect against severe and fatal COVID-19. The estimated durability of 50% VE for at least 8 months across all 3-dose heterologous COVID-19 vaccine regimens supports the adoption of heterologous prime-boost vaccination strategies, with a primary series of inactivated virus vaccine and boosting with either a viral vector or an mRNA vaccine, to prevent similar pandemics in low- and middle-income countries.
摘要：
背景：异源COVID-19疫苗有效性（VE）的持久性主要在高收入国家进行了研究，而低收入和中等收入国家对异源疫苗政策的评估仍然有限。
目的：我们旨在评估异源COVID-19疫苗方案的VE在减轻严重结局方面的持续时间，特别是重度COVID-19和COVID-19住院后的死亡仍然超过50%。
方法：我们通过将年龄≥18岁的泰国公民的记录与重要公民联系起来，形成了一个动态队列，COVID-19疫苗，和2021年5月至2022年7月的COVID-19病例登记数据库。加密的公民身份号码用于合并数据库之间的数据。本研究的重点是8种常见的异源疫苗序列：CoronaVac/ChAdOx1，ChAdOx1/BNT162b2，CoronaVac/CoronaVac/ChAdOx1/ChAdOx1，CoronaVac/ChAdOx1/BNT162b2mRNA，BBIBP-CorV/BBCorOxNT1，AdCh162b2/AdCh1/考虑非免疫个体进行比较。根据疫苗接种状态对队列进行分层，年龄,性别,省位置,一个月的疫苗接种，和结果。数据分析采用逻辑回归来确定VE，考虑潜在的混杂因素和随着时间的推移的持久性，在7个月的随访期内观察到的数据。
结果：这项研究包括52,580,841个人，大约17,907,215和17,190,975接受2剂和3剂普通异源疫苗（不相互排斥），分别。2剂量异源疫苗接种对严重COVID-19和COVID-19住院2个月后死亡提供了约50%的VE；然而，随着时间的推移，保护显著下降。3剂量异源疫苗接种对两种结果持续超过50％VE至少8个月，由具有持久性时间相互作用模型的逻辑回归确定。由CoronaVac/CoronaVac/ChAdOx1组成的疫苗序列对两种结果均显示>80％的VE，没有VE减弱的证据。最后一次给药后7个月，CoronaVac/CoronaVac/ChAdOx1对重度COVID-19和住院后死亡的最终每月测量VE为82%(95%CI80.3%-84%)和86.3%(95%CI83.6%-84%)，分别。
结论：在泰国，在7个月的观察期内，2剂量方案不能维持50％的VE对严重和致命的COVID-19超过2个月，但所有的三剂量方案都有。CoronaVac/CoronaVac/ChAdOx1方案对严重和致命的COVID-19显示出最佳的保护作用。在所有3剂异源COVID-19疫苗方案中，估计至少8个月的50%VE的持久性支持采用异源初免-加强疫苗接种策略，主要使用一系列灭活病毒疫苗，并用病毒载体或mRNA疫苗加强，防止低收入和中等收入国家发生类似的流行病。
目的：我们旨在评估异源COVID-19疫苗方案的VE在减轻严重结局方面的持续时间，特别是重度COVID-19和COVID-19住院后的死亡仍然超过50%。
方法：我们通过将年龄≥18岁的泰国公民的记录与重要公民联系起来，形成了一个动态队列，COVID-19疫苗，和2021年5月至2022年7月的COVID-19病例登记数据库。加密的公民身份号码用于合并数据库之间的数据。本研究的重点是8种常见的异源疫苗序列：CoronaVac/ChAdOx1，ChAdOx1/BNT162b2，CoronaVac/CoronaVac/ChAdOx1/ChAdOx1，CoronaVac/ChAdOx1/BNT162b2mRNA，BBIBP-CorV/BBCorOxNT1，AdCh162b2/AdCh1/考虑非免疫个体进行比较。根据疫苗接种状态对队列进行分层，年龄,性别,省位置,一个月的疫苗接种，和结果。数据分析采用逻辑回归来确定VE，考虑潜在的混杂因素和随着时间的推移的持久性，在7个月的随访期内观察到的数据。
结果：这项研究包括52,580,841个人，大约17,907,215和17,190,975接受2剂和3剂普通异源疫苗（不相互排斥），分别。2剂量异源疫苗接种对严重COVID-19和COVID-19住院2个月后死亡提供了约50%的VE；然而，随着时间的推移，保护显著下降。3剂量异源疫苗接种对两种结果持续超过50％VE至少8个月，由具有持久性时间相互作用模型的逻辑回归确定。由CoronaVac/CoronaVac/ChAdOx1组成的疫苗序列对两种结果均显示>80％的VE，没有VE减弱的证据。最后一次给药后7个月，CoronaVac/CoronaVac/ChAdOx1对重度COVID-19和住院后死亡的最终每月测量VE为82%(95%CI80.3%-84%)和86.3%(95%CI83.6%-84%)，分别。
结论：在泰国，在7个月的观察期内，2剂量方案不能维持50％的VE对严重和致命的COVID-19超过2个月，但所有的三剂量方案都有。CoronaVac/CoronaVac/ChAdOx1方案对严重和致命的COVID-19显示出最佳的保护作用。在所有3剂异源COVID-19疫苗方案中，估计至少8个月的50%VE的持久性支持采用异源初免-加强疫苗接种策略，主要使用一系列灭活病毒疫苗，并用病毒载体或mRNA疫苗加强，防止低收入和中等收入国家发生类似的流行病。
