National Institute of Public Health, (NIPHK), Prishtina, Kosovo.
The Mediterranean and Black Sea Programme for Intervention Epidemiology Training (MediPIET), European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden.
PLoS One. 2024 Jul 24;19(7):e0305629. doi: 10.1371/journal.pone.0305629. eCollection 2024.
COVID-19 vaccines have proven effective against severe outcomes in many settings, yet vaccine effectiveness (VE) estimates remain lacking for Kosovo. We aimed to estimate VE against COVID-19 infections, hospitalisations, and deaths for one and two vaccine doses during the fourth pandemic wave in July-September 2021, the period when vaccination initially became widely available.
We analysed routine surveillance data to define cases and vaccination status as partially (one dose) or completely (two doses) vaccinated. We used the screening method to calculate the proportion of cases with the outcomes vaccinated (PCV). The proportion of the population vaccinated (PPV) was based on numbers vaccinated and the Kosovo population estimate on 30/09/2021.
Between July-September 2021, 51,804 COVID-19 cases were reported in Kosovo with 9.3% of cases partially and 3.4% completely vaccinated. Estimated vaccine effectiveness for one dose was 93.1% (95%CI:92.9-93.2%) for infections, 90.3% (95%CI:88.8-91.7%) for hospitalisations, and 90.3% (95%CI:88.4-92.1%) for deaths. Estimated vaccine effectiveness for two doses was 97.8% (95%CI:97.6-97.9%) for infections, 94.5% (95%CI:93.3-95.6%) for hospitalisations, and 94.2% (95%CI: 93.7-96.5%) for deaths.
This study provides real-world evidence for COVID-19 vaccine effectiveness in Kosovo using routine administrative data sources and the screening method. COVID-19 vaccine effectiveness against infections and severe outcomes in Kosovo was higher with two vaccine doses than one dose, which is in accordance with findings from other study designs and settings. Using the screening method in our study reflects an important initial methodology for estimating vaccine effectiveness with routine surveillance that may be particularly important for low- and middle-income settings with less robust surveillance systems or fewer opportunities to conduct more robust vaccine effectiveness study designs.
在许多情况下，COVID-19 疫苗已被证明对严重后果有效，但科索沃仍缺乏疫苗有效性（VE）估计。我们旨在估计在 2021 年 7 月至 9 月第四波大流行期间，COVID-19 感染、住院和死亡的疫苗有效性，当时疫苗接种开始广泛普及。
我们分析了常规监测数据，以定义病例和接种状态为部分（一剂）或完全（两剂）接种。我们使用筛选方法计算接种病例的比例（PCV）。接种人群比例（PPV）基于接种人数和 2021 年 9 月 30 日的科索沃人口估计数。
2021 年 7 月至 9 月期间，科索沃报告了 51804 例 COVID-19 病例，其中 9.3%的病例部分接种，3.4%的病例完全接种。一剂疫苗的估计有效性为 93.1%（95%CI：92.9-93.2%），用于感染，90.3%（95%CI：88.8-91.7%）用于住院治疗，90.3%（95%CI：88.4-92.1%）用于死亡。两剂疫苗的估计有效性为 97.8%（95%CI：97.6-97.9%），用于感染，94.5%（95%CI：93.3-95.6%），用于住院治疗，94.2%（95%CI：93.7-96.5%）用于死亡。
本研究使用常规行政数据源和筛选方法为科索沃 COVID-19 疫苗有效性提供了真实世界的证据。与一剂疫苗相比，两剂疫苗在科索沃对感染和严重后果的 COVID-19 疫苗有效性更高，这与其他研究设计和环境中的发现一致。我们研究中使用筛选方法反映了一种重要的初始方法，用于使用常规监测估计疫苗有效性，对于监测系统较弱或较少有机会进行更可靠疫苗有效性研究设计的低收入和中等收入环境可能尤为重要。
