Barbieri Elisa, Cocchio Silvia, Furlan Patrizia, Scamarcia Antonio, Cantarutti Luigi, Dona' Daniele, Giaquinto Carlo, Baldo Vincenzo
Division of Paediatric Infectious Diseases, Department for Women's and Children's Health, University of Padua, Padua, Italy.
Department of Cardiac Thoracic and Vascular Sciences and Public Health, University of Padua, 35131, Padua, Italy.
Vaccine. 2024 Dec 2;42(26):126387. doi: 10.1016/j.vaccine.2024.126387. Epub 2024 Sep 26.
In the Veneto Region of Italy, universal varicella vaccination (VV) started in 2007 with a two-dose schedule at 12-15 months and 5-6 years of age achieving 90 % coverage in 2019. The study aimed at evaluating the vaccine effectiveness (VE) in children using a primary-care database METHODS: This retrospective analysis used Pedianet, a comprehensive database of 73 family paediatricians in the Veneto Region. Incidence rates (IR) of varicella were evaluated in children aged <14 years enrolled since birth, between January 2004 to April 2022. Cases were classified as breakthrough if happening beyond 42 days post-VV. Complications and prescription were evaluated. Subject were followed up from 2004 or the enrollment date, until the end of assistance/study or the first or second VV dose. Kaplan-Meier curves and log-rank tests were used to compare the varicella incidence by vaccination status. Hazard ratios of varicella infection, adjusted (aHRs) for sex, vaccinal status, age group, prematurity and socioeconomic status were estimated with Cox's regression. VE for one and two VV doses was defined as 1-aHR*.
36,498 children, followed for 233,508 person-years from 2004 to 2022 experienced 1006 cases of varicella (13 complicated and 35 breakthrough). Younger children had a higher risk of experiencing varicella compared to children aged >7 years, irrespective of their vaccination status. Indeed, the IR increased from 5.5 to 19.5 × 1000 person-years and from 1.1 to 5.4 × 1000 person-years in unvaccinated and vaccinated children aged <12 months versus those aged 5-6 years, respectively. Varicella VE was 83.4 % and 94.7 % in those vaccinated with one and two doses. After six years, the cumulative probability of experiencing varicella was 10.7 % for unvaccinated subjects, and 2.5 % and 0.4 % for those vaccinated with one and two-doses (log-rank test, p < 0.001).
Two-dose schedule VV is effective in drastically reduce varicella episodes. Breakthrough varicella episodes remain rare events.
在意大利威尼托地区，2007年开始实施普遍的水痘疫苗接种（VV），采用两剂接种程序，分别在12 - 15个月和5 - 6岁时接种，2019年覆盖率达到90%。本研究旨在利用初级保健数据库评估儿童的疫苗有效性（VE）。
这项回顾性分析使用了威尼托地区73名家庭儿科医生的综合数据库Pedianet。对2004年1月至2022年4月期间自出生起登记的14岁以下儿童的水痘发病率（IR）进行评估。如果水痘发生在VV接种后42天以上，则病例被归类为突破性病例。对并发症和处方进行评估。从2004年或登记日期开始对受试者进行随访，直至援助/研究结束或首次或第二次VV接种。使用Kaplan - Meier曲线和对数秩检验比较不同疫苗接种状态下的水痘发病率。通过Cox回归估计水痘感染的风险比，并对性别、疫苗接种状态、年龄组、早产和社会经济地位进行调整（aHRs）。一剂和两剂VV的VE定义为1 - aHR*。
2004年至2022年期间，对36498名儿童进行了233508人年的随访，共发生1006例水痘病例（13例有并发症，35例为突破性病例）。无论疫苗接种状态如何，年幼儿童患水痘的风险高于7岁以上儿童。事实上，未接种疫苗和接种疫苗的12个月以下儿童与5 - 6岁儿童相比，IR分别从5.5/1000人年增加到19.5/1000人年和从1.1/1000人年增加到5.4/1000人年。一剂和两剂接种疫苗者的水痘VE分别为83.4%和94.7%。六年后，未接种疫苗者患水痘的累积概率为10.7%，一剂和两剂接种疫苗者分别为2.5%和0.4%（对数秩检验，p < 0.001）。
两剂接种程序的VV能有效大幅减少水痘发作。突破性水痘发作仍然是罕见事件。
