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Clin Infect Dis
. 2025 Oct 16:ciaf579.
doi: 10.1093/cid/ciaf579. Online ahead of print. Absolute and Relative Effectiveness of Cell- and Egg-based Quadrivalent Inactivated Influenza Vaccine Products from 2014-2015 to 2018-2019 seasons, U.S. Flu VE Network
Manjusha Gaglani 1 2 , Chandni Raiyani 1 , Kempapura Murthy 1 , Michael Smith 1 , Briget da Graca 1 , Gueorgui Dubrocq 1 2 , Madhava Beeram 1 2 , Emily T Martin 3 , Arnold S Monto 3 , Richard K Zimmerman 4 , Mary Patricia Nowalk 4 , Erika Kiniry 5 , C Hallie Phillips 5 , Huong Q Nguyen 6 , Jennifer P King 6 , Sara S Kim 7 , Jessie R Chung 7 , Brendan Flannery 7
Affiliations
Background: Estimates of annual effectiveness of influenza vaccination combine multiple vaccine types. Reports of brand/product-specific vaccine effectiveness (VE) of egg- and cell-culture based quadrivalent inactivated influenza vaccines (IIV4/ccIIV4) are limited.
Methods: Using an observational test-negative study design, we compared effectiveness of selected IIV4 and ccIIV4 products among outpatients enrolled in the US Flu VE Network from 2014-2015 to 2018-2019. We used multivariable logistic regression to estimate product- and age-group-specific absolute and relative effectiveness of recommended, age-appropriate vaccines against symptomatic laboratory-confirmed outpatient influenza. Relative effectiveness of ccIIV4 versus IIV4 products was estimated during two seasons from 2017-2019 among participants aged ≥4 years.
Results: Pooling data from five influenza seasons when 18% and 15% of vaccinated patients had received Fluarix® Quadrivalent or Fluzone® Quadrivalent IIV4, respectively, VE against influenza was 32% for Fluarix IIV4 and 37% for Fluzone IIV4. Pooling two seasons when 11% and 28% of vaccinated patients had received ccIIV4/Flucelvax® Quadrivalent and FluLaval® Quadrivalent IIV4, respectively, VE against influenza for each product was 30%. Absolute VE compared to unvaccinated patients was lowest against influenza A(H3N2) compared to that against A(H1N1)pdm09 and each B lineage; VE point estimates were lowest among patients aged ≥50 years compared to two younger age-groups. Relative effectiveness estimates were not statistically significant, indicating similar protection across vaccine products.
Conclusion: Comparisons of influenza vaccine products over multiple seasons showed benefit against symptomatic laboratory-confirmed outpatient influenza of both egg- and cell culture-based quadrivalent inactivated influenza vaccines, with similar absolute and relative levels of protection provided by each product.
Keywords: cell-based influenza vaccine product effectiveness; comparative influenza vaccine product effectiveness; egg-based influenza vaccine product effectiveness; quadrivalent inactivated influenza vaccine product effectiveness; relative influenza vaccine product effectiveness.
. 2025 Oct 16:ciaf579.
doi: 10.1093/cid/ciaf579. Online ahead of print. Absolute and Relative Effectiveness of Cell- and Egg-based Quadrivalent Inactivated Influenza Vaccine Products from 2014-2015 to 2018-2019 seasons, U.S. Flu VE Network
Manjusha Gaglani 1 2 , Chandni Raiyani 1 , Kempapura Murthy 1 , Michael Smith 1 , Briget da Graca 1 , Gueorgui Dubrocq 1 2 , Madhava Beeram 1 2 , Emily T Martin 3 , Arnold S Monto 3 , Richard K Zimmerman 4 , Mary Patricia Nowalk 4 , Erika Kiniry 5 , C Hallie Phillips 5 , Huong Q Nguyen 6 , Jennifer P King 6 , Sara S Kim 7 , Jessie R Chung 7 , Brendan Flannery 7
Affiliations
- PMID: 41102880
- DOI: 10.1093/cid/ciaf579
Background: Estimates of annual effectiveness of influenza vaccination combine multiple vaccine types. Reports of brand/product-specific vaccine effectiveness (VE) of egg- and cell-culture based quadrivalent inactivated influenza vaccines (IIV4/ccIIV4) are limited.
Methods: Using an observational test-negative study design, we compared effectiveness of selected IIV4 and ccIIV4 products among outpatients enrolled in the US Flu VE Network from 2014-2015 to 2018-2019. We used multivariable logistic regression to estimate product- and age-group-specific absolute and relative effectiveness of recommended, age-appropriate vaccines against symptomatic laboratory-confirmed outpatient influenza. Relative effectiveness of ccIIV4 versus IIV4 products was estimated during two seasons from 2017-2019 among participants aged ≥4 years.
Results: Pooling data from five influenza seasons when 18% and 15% of vaccinated patients had received Fluarix® Quadrivalent or Fluzone® Quadrivalent IIV4, respectively, VE against influenza was 32% for Fluarix IIV4 and 37% for Fluzone IIV4. Pooling two seasons when 11% and 28% of vaccinated patients had received ccIIV4/Flucelvax® Quadrivalent and FluLaval® Quadrivalent IIV4, respectively, VE against influenza for each product was 30%. Absolute VE compared to unvaccinated patients was lowest against influenza A(H3N2) compared to that against A(H1N1)pdm09 and each B lineage; VE point estimates were lowest among patients aged ≥50 years compared to two younger age-groups. Relative effectiveness estimates were not statistically significant, indicating similar protection across vaccine products.
Conclusion: Comparisons of influenza vaccine products over multiple seasons showed benefit against symptomatic laboratory-confirmed outpatient influenza of both egg- and cell culture-based quadrivalent inactivated influenza vaccines, with similar absolute and relative levels of protection provided by each product.
Keywords: cell-based influenza vaccine product effectiveness; comparative influenza vaccine product effectiveness; egg-based influenza vaccine product effectiveness; quadrivalent inactivated influenza vaccine product effectiveness; relative influenza vaccine product effectiveness.