Department of Epidemiology, School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China.
Suzhou Center for Disease Control and Prevention, Suzhou, China.
Vaccine. 2020 Dec 3;38(51):8200-8205. doi: 10.1016/j.vaccine.2020.10.069. Epub 2020 Nov 8.
There are few estimates of vaccination-averted influenza-associated illnesses in China.
We used a mathematical model and Monte Carlo algorithm to estimate numbers and 95% confidence intervals (CI) of influenza-associated outcomes (hospitalization, illness, and medically-attended (MA) illness) averted by vaccination among children aged 6-59 months in Suzhou from October 2011-September 2016. Influenza illnesses included non-hospitalized MA influenza illnesses and non-MA influenza illnesses. The numbers of influenza-associated outcomes averted by vaccination were the difference between the expected burden if there were no vaccination given and the observed burden with vaccination. The model incorporated the disease burden estimated based on surveillance data from Suzhou University Affiliated Children's Hospital (SCH) and data from health utilization surveys conducted in the catchment area of SCH, age-specific estimates of influenza vaccination coverage in Suzhou from the Expanded Program on Immunization database, and influenza vaccine effectiveness estimates from previous publications. Averted influenza estimations were presented as absolute numbers and in terms of the prevented fraction (PF). A hypothetical scenario with 50% coverage (but identical vaccine effectiveness) over the study period was also modeled.
In ~250,000 children, influenza vaccination prevented an estimated 731 (CI: 549-960) influenza hospitalizations (PF: 6.2% of expected, CI: 5.8-6.6%) and 10,024 (7593-12,937) influenza illnesses (PF: 6.5%, 6.4-6.7%), of which 8342 (6338-10,768) were MA (PF: 6.6%, 6.4-6.7%) from 2011 to 2016. The PFs declined each year along with decreasing influenza vaccination coverage. If 50% of the study population had been vaccinated over time, the estimated numbers of averted cases during the study period would have been 4059 (3120-5762) influenza hospitalizations (PF: 27.2%, 26.4-27.9%) and 56,215 (42,925-78,849) influenza illnesses (PF: 28.5%, 28.3-28.7%), of which 46,596 (35,662-65,234) would be MA (PF: 28.5%, 28.3-28.7%).
Influenza vaccination is estimated to have averted influenza-associated illness outcomes even with low coverage in children aged 6-59 months in Suzhou. Increasing influenza vaccination coverage in this population could further reduce illnesses and hospitalizations.
在中国，鲜有关于疫苗预防流感相关疾病的估计。
我们使用数学模型和蒙特卡罗算法来估计 2011 年 10 月至 2016 年 9 月期间，苏州 6-59 月龄儿童接种疫苗预防流感相关结局（住院、发病和就医（MA）疾病）的数量和 95%置信区间（CI）。流感相关疾病包括非住院 MA 流感疾病和非 MA 流感疾病。接种疫苗预防的流感相关结局数量为无疫苗接种时的预期负担与接种疫苗时的实际负担之间的差值。该模型结合了苏州大学附属儿童医院（SCH）监测数据估算的疾病负担、SCH 流域健康利用调查数据、免疫规划数据库中苏州特定年龄组流感疫苗接种率估计值以及先前出版物中流感疫苗效力估计值。以绝对数字和预防分数（PF）表示预防的流感估计数。还对研究期间 50%覆盖率（但疫苗效力相同）的假设情况进行了建模。
在大约 250000 名儿童中，流感疫苗预防了估计 731 例（CI：549-960）流感住院（PF：预期的 6.2%，CI：5.8-6.6%）和 10024 例（7593-12937）流感发病（PF：6.5%，6.4-6.7%），其中 2011 年至 2016 年期间有 8342 例（6338-10768）为 MA（PF：6.6%，6.4-6.7%）。随着流感疫苗接种率的下降，PF 每年都在下降。如果研究人群中 50%的人随着时间的推移接种了疫苗，那么在研究期间估计可预防的病例数将为 4059 例（3120-5762）流感住院（PF：27.2%，26.4-27.9%）和 56215 例（42925-78849）流感发病（PF：28.5%，28.3-28.7%），其中 46596 例（35662-65234）为 MA（PF：28.5%，28.3-28.7%）。
即使苏州 6-59 月龄儿童的流感疫苗接种覆盖率较低，也可估计流感疫苗接种可预防流感相关疾病结局。增加该人群的流感疫苗接种覆盖率可能会进一步减少发病和住院。
