Clalit Research Institute, Innovation Division, Clalit Health Services, Ramat Gan, Israel; School of Public Health, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel; University of Michigan, School of Public Health, Ann Arbor, MI, USA.
Schneider Children's Medical Center of Israel, Petach Tikvah, Israel.
Vaccine. 2022 Jan 24;40(3):512-520. doi: 10.1016/j.vaccine.2021.11.092. Epub 2021 Dec 10.
Methodologically rigorous studies on Covid-19 vaccine effectiveness (VE) in preventing SARS-CoV-2 infection are critically needed to inform national and global policy on Covid-19 vaccine use. In Israel, healthcare personnel (HCP) were initially prioritized for Covid-19 vaccination, creating an ideal setting to evaluate early real-world VE in a closely monitored population.
We conducted a prospective study among HCP in 6 hospitals to estimate the effectiveness of the BNT162b2 mRNA Covid-19 vaccine in preventing SARS-CoV-2 infection. Participants filled out weekly symptom questionnaires, provided weekly nasal specimens, and three serology samples - at enrollment, 30 days and 90 days. We estimated VE against PCR-confirmed SARS-CoV-2 infection using the Cox Proportional Hazards model and against a combined PCR/serology endpoint using Fisher's exact test.
Of the 1567 HCP enrolled between December 27, 2020 and February 15, 2021, 1250 previously uninfected participants were included in the primary analysis; 998 (79.8%) were vaccinated with their first dose prior to or at enrollment, all with Pfizer BNT162b2 mRNA vaccine. There were four PCR-positive events among vaccinated participants, and nine among unvaccinated participants. Adjusted two-dose VE against any PCR-confirmed infection was 94.5% (95% CI: 82.6%-98.2%); adjusted two-dose VE against a combined endpoint of PCR and seroconversion for a 60-day follow-up period was 94.5% (95% CI: 63.0%-99.0%). Five PCR-positive samples from study participants were sequenced; all were alpha variant.
Our prospective VE study of HCP in Israel with rigorous weekly surveillance found very high VE for two doses of Pfizer BNT162b2 mRNA vaccine against SARS-CoV-2 infection in recently vaccinated HCP during a period of predominant alpha variant circulation.
Clalit Health Services.
为了为新冠病毒疫苗的使用提供国家和全球政策依据，迫切需要在方法学上严谨的新冠病毒疫苗有效性（VE）研究来预防 SARS-CoV-2 感染。在以色列，医疗保健人员（HCP）最初被优先接种新冠病毒疫苗，这为在密切监测的人群中评估早期真实世界 VE 创造了理想的环境。
我们在 6 家医院对 HCP 进行了一项前瞻性研究，以评估 BNT162b2 mRNA 新冠病毒疫苗预防 SARS-CoV-2 感染的效果。参与者每周填写症状问卷，提供每周鼻拭子，并在入组时、第 30 天和第 90 天提供 3 份血清样本。我们使用 Cox 比例风险模型估计针对 PCR 确诊的 SARS-CoV-2 感染的 VE，并使用 Fisher 确切检验估计针对 PCR/血清学联合终点的 VE。
在 2020 年 12 月 27 日至 2021 年 2 月 15 日期间，共招募了 1567 名 HCP，其中 1250 名先前未感染的参与者被纳入主要分析；998 名（79.8%）参与者在入组前或入组时接种了第一剂疫苗，均使用辉瑞公司的 BNT162b2 mRNA 疫苗。接种疫苗的参与者中有 4 例 PCR 阳性事件，未接种疫苗的参与者中有 9 例。调整后的两剂 VE 针对任何 PCR 确诊感染为 94.5%（95%CI：82.6%-98.2%）；调整后的两剂 VE 针对 60 天随访期的 PCR 和血清转化联合终点为 94.5%（95%CI：63.0%-99.0%）。从研究参与者中获得的 5 个 PCR 阳性样本进行了测序；均为 alpha 变异株。
我们对以色列 HCP 的前瞻性 VE 研究发现，在 alpha 变异株流行期间，最近接种辉瑞 BNT162b2 mRNA 疫苗的 HCP 中，两剂疫苗对 SARS-CoV-2 感染的 VE 非常高。
Clalit 医疗保健服务。
