tetano
Editor, Senior Moderator
Clin Infect Dis
. 2021 Jan 5;ciaa1944.
doi: 10.1093/cid/ciaa1944. Online ahead of print.
Relative Effectiveness of the Cell-Derived Inactivated Quadrivalent Influenza Vaccine Versus Egg-Derived Inactivated Quadrivalent Influenza Vaccines in Preventing Influenza-Related Medical Encounters During the 2018-2019 Influenza Season in the United States
Constantina Boikos[SUP] 1 [/SUP], Lauren Fischer[SUP] 2 [/SUP], Dan O'Brien[SUP] 2 [/SUP], Joe Vasey[SUP] 2 [/SUP], Gregg C Sylvester[SUP] 3 [/SUP], James A Mansi[SUP] 1 [/SUP]
Affiliations
Abstract
Background: The cell-propagated inactivated quadrivalent influenza vaccine (ccIIV4) may offer improved protection in seasons where egg-derived influenza viruses undergo mutations that affect antigenicity. This study estimated the relative vaccine effectiveness (rVE) of ccIIV4 versus egg-derived inactivated quadrivalent influenza vaccine (eIIV4) in preventing influenza-related medical encounters in the 2018-2019 U.S. season.
Methods: A dataset linking primary care electronic medical records with medical claims data was used to conduct a retrospective cohort study among individuals ≥4 years vaccinated with ccIIV4 or eIIV4 during the 2018-2019 season. Adjusted odds ratios (ORs) were derived from a doubly robust inverse probability of treatment-weighted approach adjusting for age, sex, race, ethnicity, geographic region, vaccination week, and health status. Relative vaccine effectiveness (rVE) was estimated by (1-OR)*100 and presented with 95% confidence intervals (CI).
Results: Following the application of inclusion/exclusion criteria, the study cohort included 2,125,430 ccIIV4 and 8,000,903 eIIV4 recipients. Adjusted analyses demonstrated a greater reduction in influenza-related medical encounters with ccIIV4 versus eIIV4, with the following rVE: overall, 7.6% (95% CI 6.5-8.6); age 4-17 years, 3.9% (0.9-7.0); 18-64 years, 6.5% (5.2-7.9); 18-49 years, 7.5% (5.7-9.3); 50-64 years, 5.6% (3.6-7.6); and ≥65 years, -2.2% (-5.4 to 0.9).
Conclusions: Adjusted analyses demonstrated statistically significantly greater reduction in influenza-related medical encounters in individuals vaccinated with ccIIV4 vs eIIV4 in the 2018-2019 U.S. influenza season. These results support ccIIV4 as a potentially more effective public health measure against influenza than an egg-based equivalent.
Keywords: cell-derived influenza vaccine; egg-derived influenza vaccine; influenza; quadrivalent inactivated influenza vaccine; relative vaccine effectiveness.
. 2021 Jan 5;ciaa1944.
doi: 10.1093/cid/ciaa1944. Online ahead of print.
Relative Effectiveness of the Cell-Derived Inactivated Quadrivalent Influenza Vaccine Versus Egg-Derived Inactivated Quadrivalent Influenza Vaccines in Preventing Influenza-Related Medical Encounters During the 2018-2019 Influenza Season in the United States
Constantina Boikos[SUP] 1 [/SUP], Lauren Fischer[SUP] 2 [/SUP], Dan O'Brien[SUP] 2 [/SUP], Joe Vasey[SUP] 2 [/SUP], Gregg C Sylvester[SUP] 3 [/SUP], James A Mansi[SUP] 1 [/SUP]
Affiliations
- PMID: 33400775
- DOI: 10.1093/cid/ciaa1944
Abstract
Background: The cell-propagated inactivated quadrivalent influenza vaccine (ccIIV4) may offer improved protection in seasons where egg-derived influenza viruses undergo mutations that affect antigenicity. This study estimated the relative vaccine effectiveness (rVE) of ccIIV4 versus egg-derived inactivated quadrivalent influenza vaccine (eIIV4) in preventing influenza-related medical encounters in the 2018-2019 U.S. season.
Methods: A dataset linking primary care electronic medical records with medical claims data was used to conduct a retrospective cohort study among individuals ≥4 years vaccinated with ccIIV4 or eIIV4 during the 2018-2019 season. Adjusted odds ratios (ORs) were derived from a doubly robust inverse probability of treatment-weighted approach adjusting for age, sex, race, ethnicity, geographic region, vaccination week, and health status. Relative vaccine effectiveness (rVE) was estimated by (1-OR)*100 and presented with 95% confidence intervals (CI).
Results: Following the application of inclusion/exclusion criteria, the study cohort included 2,125,430 ccIIV4 and 8,000,903 eIIV4 recipients. Adjusted analyses demonstrated a greater reduction in influenza-related medical encounters with ccIIV4 versus eIIV4, with the following rVE: overall, 7.6% (95% CI 6.5-8.6); age 4-17 years, 3.9% (0.9-7.0); 18-64 years, 6.5% (5.2-7.9); 18-49 years, 7.5% (5.7-9.3); 50-64 years, 5.6% (3.6-7.6); and ≥65 years, -2.2% (-5.4 to 0.9).
Conclusions: Adjusted analyses demonstrated statistically significantly greater reduction in influenza-related medical encounters in individuals vaccinated with ccIIV4 vs eIIV4 in the 2018-2019 U.S. influenza season. These results support ccIIV4 as a potentially more effective public health measure against influenza than an egg-based equivalent.
Keywords: cell-derived influenza vaccine; egg-derived influenza vaccine; influenza; quadrivalent inactivated influenza vaccine; relative vaccine effectiveness.