This project aimed to provide real-world evidence on the comparative effectiveness of influenza vaccines in seniors using MarketScan® databases. This retrospective cohort study compared the effectiveness of standard-dose (SD) trivalent, high-dose (HD) trivalent, SD quadrivalent, and adjuvanted trivalent influenza vaccines in cohorts of Medicare beneficiaries 65 years of age and older over six influenza seasons (2012/2013-2017/2018 seasons).
We analyzed the data pooled from all six seasons as well as each season separately. In the pooled analysis across all seasons, HD trivalent was associated with a lower risk of influenza-related hospitalization versus SD trivalent or SD quadrivalent. HD trivalent was also associated with a lower risk for pneumonia-related hospitalization than SD trivalent. Adjuvanted trivalent was associated with a higher risk for influenza-related outpatient visits than HD trivalent, SD trivalent, or SD quadrivalent. Risk estimates varied across seasons. Compared to SD trivalent, subjects who received HD trivalent had a lower risk of influenza- or pneumonia-related hospitalization in 2015/2016, 2013/2014, and 2012/2013 seasons, and a lower risk of influenza-related outpatient visits in 2017/2018 and 2012/2013 seasons. Compared to SD quadrivalent, HD trivalent was associated with a decreased risk of hospitalized influenza or pneumonia in 2013/2014 and a lower risk of influenza-related outpatient visits in 2014/2015. Compared to adjuvanted trivalent, HD trivalent was associated with a lower risk of influenza-related outpatient visits in 2017/2018.
Results were presented in July 2020 for the CORE Summer Student Seminar Series at the Research Institute of the McGill University Health Centre and to the PHAC/NACI working group in November 2020. Final results were presented to the PHAC/NACI working group in February 2021.
For more information, contact: Autumn Neville, Research Coordinator. [email protected]
This research is funded by CIHR-DSEN
Lead investigator: Dr. Sasha Bernatsky
Query 19-07 raised by Public Health Agency of Canada, Infectious Disease Prevention and Control, Centre for Immunization and Respiratory Infectious Diseases