Department of Infectious Diseases, Istituto Superiore di Sanità (Italian National Institute of Health), Rome, Italy.
Department of Infectious Diseases, Istituto Superiore di Sanità (Italian National Institute of Health), Rome, Italy.
Vaccine. 2018 Mar 7;36(11):1435-1443. doi: 10.1016/j.vaccine.2018.01.065. Epub 2018 Feb 7.
Vaccination has determined a dramatic decline in morbidity and mortality from infectious diseases over the last century. However, low perceived risk of the infectious threat and increased concern about vaccines' safety led to a reduction in vaccine coverage, with increased risk of disease outbreaks.
Annual surveillance data of nationally communicable infectious diseases in Italy between 1900 and 2015 were used to derive trends in morbidity and mortality rates before and after vaccine introduction, focusing particularly on the effect of vaccination programs. Autoregressive integrated moving average models were applied to ten vaccine-preventable diseases: diphtheria, tetanus, poliomyelitis, hepatitis B, pertussis, measles, mumps, rubella, chickenpox, and invasive meningococcal disease. Results of these models referring to data before the immunization programs were projected on the vaccination period to estimate expected cases. The difference between observed and projected cases provided estimates of cases avoided by vaccination.
The temporal trend for each disease started with high incidence rates, followed by a period of persisting reduction. After vaccine introduction, and particularly after the recommendation for universal use among children, the current rates were much lower than those forecasted without vaccination, both in the whole population and among the 0-to-4 year olds, which is, generally, the most susceptible age class. Assuming that the difference between incidence rates before and after vaccination programs was attributable only to vaccine, more than 4 million cases were prevented, and nearly 35% of them among children in the early years of life. Diphtheria was the disease with the highest number of prevented cases, followed by mumps, chickenpox and measles.
Universal vaccination programs represent the most effective prevention tool against infectious diseases, having a major impact on human health. Health authorities should make any effort to strengthen public confidence in vaccines, highlighting scientific evidence of vaccination benefits.
在过去的一个世纪里，疫苗接种极大地降低了传染病的发病率和死亡率。然而，由于人们对传染病威胁的感知风险较低，以及对疫苗安全性的担忧增加，导致疫苗接种率下降，疾病爆发的风险增加。
使用意大利 1900 年至 2015 年期间全国传染病的年度监测数据，分析疫苗接种前后发病率和死亡率的趋势，重点关注疫苗接种计划的效果。应用自回归积分移动平均模型分析了十种可通过疫苗预防的疾病：白喉、破伤风、脊髓灰质炎、乙型肝炎、百日咳、麻疹、腮腺炎、风疹、水痘和侵袭性脑膜炎球菌病。这些模型针对免疫接种计划之前的数据进行了分析，并将结果预测到接种期，以估计预期病例数。观察到的病例数与预测病例数之间的差异提供了疫苗接种避免的病例数估计。
每种疾病的时间趋势都是从高发病率开始，然后是持续减少的时期。在疫苗接种后，特别是在建议儿童普遍使用疫苗后，目前的发病率远低于没有接种疫苗的预测发病率，无论是在整个人群中，还是在最易感染的 0 至 4 岁年龄段中。假设疫苗接种前后发病率的差异仅归因于疫苗，那么就可以预防超过 400 万例病例，其中近 35%发生在生命早期的儿童中。白喉是预防病例数最多的疾病，其次是腮腺炎、水痘和麻疹。
普遍接种疫苗计划是预防传染病最有效的手段，对人类健康产生了重大影响。卫生当局应尽一切努力加强公众对疫苗的信心，突出疫苗接种益处的科学证据。
