Nordström Peter, Ballin Marcel, Nordström Anna
Department of Community Medicine and Rehabilitation, Unit of Geriatric Medicine, Umeå University, Umeå, Sweden (Peter Nordström and Marcel Ballin).
Department of Public Health and Clinical Medicine, Section of Sustainable Health, Umeå University, Umeå, Sweden (Marcel Ballin and Anna Nordström).
Lancet Reg Health Eur. 2021 Dec;11:100249. doi: 10.1016/j.lanepe.2021.100249. Epub 2021 Oct 18.
The effectiveness of heterologous prime-boost Coronavirus disease 2019 (Covid-19) vaccination is currently unknown.
From individuals vaccinated with two doses against Covid-19 in Sweden until July 5, 2021 (N=3,445,061), we formed a study cohort including 94,569 individuals that had received heterologous ChAdOx1 nCoV-19 / BNT162b2 prime-boost vaccination, 16,402 individuals that received heterologous ChAdOx1 nCoV-19 / mRNA-1273 prime-boost vaccination, and 430,100 individuals that received homologous ChAdOx1 nCoV-19 / ChAdOx1 nCoV-19 prime-boost vaccination. In addition, 180,716 individuals were selected who were unvaccinated at the date of vaccination in the corresponding case. Unvaccinated individuals were censored at first dose of any vaccine. Baseline was the date of the second dose of any vaccine, with the same date in the corresponding unvaccinated individual. The outcome included incident symptomatic Covid-19 infection occurring >14 days after baseline.
During a mean follow-up time of 76 (range 1-183) days, symptomatic Covid-19 infection was confirmed in 187 individuals with heterologous vaccine schedules (incidence rate: 2.0/100,000 person-days) and in 306 individuals from the unvaccinated control group (incidence rate: 7.1/100,000 person-days). The adjusted vaccine effectiveness was 67% (95% CI, 59-73, P<0.001) for heterologous ChAdOx1 nCoV-19 / BNT162b2 prime-boost vaccination, and 79% (95% CI, 62-88, P<0.001) for heterologous ChAdOx1 nCoV-19 / mRNA-1273 prime-boost vaccination. When combined and analysed together, the two heterologous vaccine schedules had an effectiveness of 68% (95% CI, 61-74, P<0.001) which was significantly greater (P<0.001) than the 50% effectiveness for homologous ChAdOx1 nCoV-19 / ChAdOx1 nCoV-19 (95% CI, 41-58, P<0.001).
The findings of this study suggest that the use of heterologous ChAdOx1 nCoV-19 and mRNA prime-boost vaccination is an effective alternative to increase population immunity against Covid-19, including against the Delta variant which dominated the confirmed cases during the study period. These findings could have important implications for vaccination strategies and logistics, and consequently in the battle against the Covid-19 pandemic.
目前尚不清楚异源初免-加强新型冠状病毒肺炎（Covid-19）疫苗接种的有效性。
在瑞典接种两剂Covid-19疫苗的个体中，截至2021年7月5日（N = 3,445,061），我们组建了一个研究队列，其中包括94,569名接受异源ChAdOx1 nCoV-19 / BNT162b2初免-加强疫苗接种的个体、16,402名接受异源ChAdOx1 nCoV-19 / mRNA-1273初免-加强疫苗接种的个体，以及430,100名接受同源ChAdOx1 nCoV-19 / ChAdOx1 nCoV-19初免-加强疫苗接种的个体。此外，选取了180,716名在相应情况下接种疫苗时未接种的个体。未接种个体在接种任何疫苗的第一剂时被截尾。基线为任何疫苗的第二剂接种日期，与相应未接种个体的日期相同。结局包括在基线后>14天发生的有症状Covid-19感染。
在平均76天（范围1 - 183天）的随访期内，187名采用异源疫苗接种方案的个体确诊有症状Covid-19感染（发病率：2.0/100,000人日），未接种对照组中有306名个体确诊（发病率：7.1/100,000人日）。异源ChAdOx1 nCoV-19 / BNT162b2初免-加强疫苗接种的调整后疫苗效力为67%（95%CI，59 - 73，P<0.001），异源ChAdOx1 nCoV-19 / mRNA-1273初免-加强疫苗接种的调整后疫苗效力为79%（95%CI，62 - 88，P<0.001）。当将两种异源疫苗接种方案合并分析时，其效力为68%（95%CI，61 - 74，P<0.001），显著高于同源ChAdOx1 nCoV-19 / ChAdOx1 nCoV-19的50%效力（95%CI，41 - 58，P<0.001）。
本研究结果表明，使用异源ChAdOx1 nCoV-19和mRNA初免-加强疫苗接种是提高人群对Covid-19免疫力的有效替代方案，包括针对在研究期间主导确诊病例的Delta变异株。这些发现可能对疫苗接种策略和后勤保障具有重要意义，从而在抗击Covid-19大流行中发挥作用。
