Kaiser Permanente Vaccine Study Center, Oakland, California;
Department of Epidemiology, Merck Sharp & Dohme Corp, Whitehouse Station, New Jersey;
Pediatrics. 2014 Jul;134(1):24-30. doi: 10.1542/peds.2013-4251. Epub 2014 Jun 9.
When varicella vaccine was licensed in the United States in 1995, there were concerns that childhood vaccination might increase the number of adolescents susceptible to varicella and shift disease toward older age groups where it can be more severe.
We conducted a series of 5 cross-sectional studies in 1994 to 1995 (prevaccine), 2000, 2003, 2006, and 2009 in Kaiser Permanente of Northern California to assess changes in varicella epidemiology in children and adolescents, as well as changes in varicella hospitalization in people of all ages. For each study, information on varicella history and varicella occurrence during the past year was obtained by telephone survey from a sample of ∼8000 members 5 to 19 years old; varicella hospitalization rates were calculated for the entire membership.
Between 1995 and 2009, the overall incidence of varicella in 5- to 19-year-olds decreased from 25.8 to 1.3 per 1000 person-years, a ∼90% to 95% decline in the various age categories (5-9, 10-14, and 15-19 years of age). The proportion of varicella-susceptible children and adolescents also decreased in all age groups, including in 15- to 19-year-olds (from 15.6% in 1995 to 7.6% in 2009). From 1994 to 2009, age-adjusted varicella hospitalization rates in the general member population decreased from 2.13 to 0.25 per 100,000, a ∼90% decline.
In the 15 years after the introduction of varicella vaccine, a major reduction in varicella incidence and hospitalization was observed with no evidence of a shift in the burden of varicella to older age groups.
1995 年美国批准使用水痘疫苗时，人们担心儿童接种疫苗可能会增加青少年患水痘的人数，并使疾病向年龄更大的人群转移，在这些人群中，水痘可能更为严重。
我们在 1994 年至 1995 年（疫苗前）、2000 年、2003 年、2006 年和 2009 年在北加利福尼亚凯泽永久医疗集团进行了一系列 5 项横断面研究，以评估儿童和青少年中水痘流行病学的变化，以及所有年龄段人群中水痘住院的变化。对于每项研究，通过电话调查从大约 8000 名 5 至 19 岁的成员中获得了过去一年中水痘病史和水痘发病的信息；为整个成员计算了水痘住院率。
1995 年至 2009 年，5 至 19 岁人群的水痘总发病率从 25.8/1000 人年降至 1.3/1000 人年，各年龄段（5-9 岁、10-14 岁和 15-19 岁）的发病率下降了 90%至 95%。在所有年龄段，包括 15 至 19 岁年龄段，水痘易感儿童和青少年的比例也有所下降（从 1995 年的 15.6%降至 2009 年的 7.6%）。1994 年至 2009 年，普通成员人群中年龄调整后的水痘住院率从 2.13/100000 降至 0.25/100000，下降了约 90%。
在引入水痘疫苗后的 15 年内，水痘发病率和住院率显著下降，没有证据表明水痘负担向年龄更大的人群转移。
