Effectiveness of the Cell-Derived Inactivated Quadrivalent Influenza Vaccine in Individuals at High Risk of Influenza Complications in the 2018–2019 United States Influenza Season. (2nd April 2021)

• Record Type: Journal Article
• Authors: Boikos, Constantina; Imran, Mahrukh; Nguyen, Van Hung; Ducruet, Thierry; Sylvester, Gregg C; Mansi, James A
• Is Part Of: Open forum infectious diseases. Volume 8:Number 7(2021)
• Publication Date: 2021-04-02
• Subjects: cIIV4 -- eIIV4 -- influenza -- quadrivalent influenza vaccine -- relative vaccine effectiveness; Communicable diseases -- Periodicals; Medical microbiology -- Periodicals; Infection -- Periodicals; 616.9
• DOI: 10.1093/ofid/ofab167
• Languages: English
• ISSNs: 2328-8957

Abstract

Abstract: Background: Higher rates of influenza-related morbidity and mortality occur in individuals with underlying medical conditions. To improve vaccine effectiveness, cell-based technology for influenza vaccine manufacturing has been developed. Cell-derived inactivated quadrivalent influenza vaccines (cIIV4) may improve protection in seasons in which egg-propagated influenza viruses undergo mutations that affect antigenicity. This study aimed to estimate the relative vaccine effectiveness (rVE) of cIIV4 versus egg-derived inactivated quadrivalent influenza vaccines (eIIV4) in preventing influenza-related medical encounters in individuals with underlying medical conditions putting them at high risk of influenza complications during the 2018–2019 US influenza season. Methods: An integrated dataset, linking primary care electronic medical records with claims data, was used to conduct a retrospective cohort study among individuals aged ≥4 years, with ≥1 health condition, vaccinated with cIIV4 or eIIV4 during the 2018–2019 season. Adjusted odds ratios (ORs) were derived using a doubly robust inverse probability of treatment-weighting (IPTW) model, adjusting for age, sex, race, ethnicity, geographic region, vaccination week, and health status. Relative vaccine effectiveness was estimated by (1 − OR) × 100 and presented with 95% confidence intervals (CIs). Results: The study cohort included 471 301 cIIV4 and 1 641 915 eIIV4 recipients. Compared with eIIV4, cIIV4 prevented significantly more influenza-related medical encounters among individuals with ≥1 health condition (rVE, 13.4% [95% CI, 11.4%–15.4%]), chronic pulmonary disease (rVE, 18.7% [95% CI, 16.0%–21.3%]), and rheumatic disease (rVE, 11.8% [95% CI, 3.6%–19.3%]). Conclusions: Our findings support the use of cIIV4 in individuals ≥4 years of age at high risk of influenza complications and provide further evidence supporting improved effectiveness of cIIV4 compared with eIIV4. Abstract : During the 2018–2019 season, a cell culture-derived quadrivalent-inactivated influenza vaccine prevented significantly more influenza-related medical encounters among individuals aged ≥4 years with at least 1 health condition putting them at high risk of influenza complications.