McGovern Ian, Sardesai Aditya, Taylor Alexandra, Toro-Diaz Hector, Haag Mendel
Seqirus USA Inc, Center for Outcomes Research and Epidemiology, Cambridge, Massachusetts, USA.
Evidera, Evidence Synthesis, Modeling & Communication, San Francisco, California, USA.
Open Forum Infect Dis. 2023 Aug 9;10(8):ofad429. doi: 10.1093/ofid/ofad429. eCollection 2023 Aug.
The MF59-adjuvanted trivalent inactivated influenza vaccine (aIIV3) is designed to overcome immunosenescence and enhance vaccine responses in older adults. We expanded on the Centers for Disease Control and Prevention (CDC) modeling method to estimate the number of additional influenza-related outcomes averted with aIIV3 versus generic quadrivalent inactivated influenza vaccine (IIV4) in adults ≥65 years over 3 influenza seasons (2017-2018 to 2019-2020) in the United States.
A static compartmental model was developed based on an existing CDC model with 2 previously recommended calculation methods that increased the accuracy of the model in providing estimates of burden averted. Model inputs included vaccine effectiveness, vaccine coverage, population counts, and disease burden estimates. Additional burden averted (symptomatic cases, outpatient visits, hospitalizations, intensive care unit [ICU] admissions, and deaths) was expressed as total incremental cases averted between the vaccines. Sensitivity analyses tested the resilience of the model results to uncertainties in model inputs.
The model estimated that vaccination with aIIV3 versus IIV4 would avert 2.24 times as many symptomatic cases, outpatient visits, hospitalizations, ICU stays, and deaths during 2017-2018; the burden averted in 2018-2019 and 2019-2020 with aIIV3 would be 3.44 and 1.72 times that averted with IIV4, respectively. Disease burden estimates and relative vaccine effectiveness of aIIV3 had the greatest impact on model estimates.
Over 3 influenza seasons, the model estimated that aIIV3 was more effective than IIV4 in averting influenza-related outcomes, preventing 1.72 to 3.44 times as many influenza illnesses with proportionate decreases in related healthcare use and complications.
MF59佐剂三价灭活流感疫苗（aIIV3）旨在克服免疫衰老并增强老年人的疫苗反应。我们扩展了美国疾病控制与预防中心（CDC）的建模方法，以估计在3个流感季节（2017 - 2018年至2019 - 2020年）中，美国65岁及以上成年人使用aIIV3与普通四价灭活流感疫苗（IIV4）相比可避免的额外流感相关结局的数量。
基于现有的CDC模型开发了一个静态分区模型，采用2种先前推荐的计算方法，提高了模型在提供避免负担估计方面的准确性。模型输入包括疫苗效力、疫苗接种率、人口数量和疾病负担估计。额外避免的负担（有症状病例、门诊就诊、住院、重症监护病房[ICU]入院和死亡）表示为两种疫苗之间避免的总增量病例数。敏感性分析测试了模型结果对模型输入不确定性的弹性。
模型估计，在2017 - 2018年期间，接种aIIV3与IIV4相比可避免的有症状病例、门诊就诊、住院、ICU住院天数和死亡数量是后者的2.24倍；2018 - 2019年和2019 - 2020年使用aIIV3避免的负担分别是使用IIV4的3.44倍和1.72倍。aIIV3的疾病负担估计和相对疫苗效力对模型估计影响最大。
在3个流感季节中，模型估计aIIV3在避免流感相关结局方面比IIV4更有效，可预防的流感疾病数量是IIV4的1.72至3.44倍，同时相关医疗保健使用和并发症也相应减少。
