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. 2025 Aug 27;14(8):piaf069.
doi: 10.1093/jpids/piaf069.

Effectiveness of Cell Culture-Based Influenza Vaccine, 2023-2024

Affiliations

Effectiveness of Cell Culture-Based Influenza Vaccine, 2023-2024

Huong Q Nguyen et al. J Pediatric Infect Dis Soc. .

Abstract

Background: The cell culture-based inactivated influenza vaccine (ccIIV) was first approved for use in children aged 4-17 years in 2016 in the United States. The approved age indication for ccIIV was expanded to include children 6 months and older beginning the 2022-2023 season. There is limited real-world data on ccIIV effectiveness in children. We assessed ccIIV effectiveness using the test-negative design during the 2023-2024 season.

Methods: Patients aged 6 months to 64 years who sought outpatient or telehealth care for acute respiratory illness were actively recruited between October 2023 and May 2024. Symptom eligibility criteria included cough, with an illness duration of ≤ 7 days. Respiratory samples were tested by reverse transcription polymerase chain reaction to identify influenza cases. Vaccination dates and products were determined by immunization records. Analyses were restricted to ccIIV recipients and unvaccinated participants. Cell culture-based inactivated influenza vaccine effectiveness was estimated as [100% × (1 - odds ratio)] for vaccination in cases versus test-negative controls, with adjustment for age and calendar time.

Results: Among 1850 participants, 12% were age 6 months to 3 years, 32% were age 4-17 years, and 56% were age 18-64 years. Influenza was detected in 505 (27%) participants; 267 had influenza A/H1N1pdm09; 149 had influenza B; 56 had influenza A/H3N2; and 33 had influenza A with unknown subtype. A total of 470 (25%) received ccIIV. Among children (age 6 months to 17 years), ccIIV effectiveness was 64% [95% confidence interval (CI), 37%-81%] against influenza A/H1N1pdm09, 75% (95% CI, 43%-91%) against influenza B, and 76% (95% CI, 4%-97%) against influenza A/H3N2. Among adults (age 18-64 years), ccIIV effectiveness was 56% (95% CI, 31%-73%) against influenza A/H1N1pdm09, 62% (95% CI, 13%-86%) against influenza B, and 33% (95% CI, -62% to 76%) against influenza A/H3N2. Young children aged 6 months to 3 years had the highest point estimates (88%-98%).

Conclusion: Cell culture-based inactivated influenza vaccine generated substantial real-world effectiveness against medically attended, laboratory-confirmed influenza in children and adults during a season when influenza A/H1N1pdm09 viruses predominated and influenza B and influenza A/H3N2 co-circulated at lower levels.

Keywords: cell-based influenza vaccine; influenza; pediatric; vaccine effectiveness.

Plain language summary

Effectiveness of cell culture-based inactivated influenza vaccine was estimated during the 2023-2024 season. The cell culture-based inactivated influenza vaccine effectiveness was 64%-76% against medically attended influenza in children and 33%-62% in working-aged adults. The youngest children had the highest point estimates (88%-98%).

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Conflict of interest statement

H.Q.N. received research support from CSL Seqirus, ModernaTX, and GSK, and has served on scientific advisory boards for CSL Seqirus and ModernaTX. O.D.A. received research support from CSL Seqirus, ModernaTX, and GSK. K.E.H., E.S., J.G.P., A.B., J.K.M., and E.A.B. received research support from CSL Seqirus and ModernaTX. K.A., A.G., and G.C.S. are employees of CSL Seqirus.

Figures

Figure 1
Figure 1
Study Flow Chart. Abbreviations: LAIV, live attenuated influenza vaccine; N, sample size; n, number; RIV, recombinant influenza vaccine; SD-IIV, quadrivalent standard-dose, egg-based inactivated influenza vaccine
Figure 2
Figure 2
Influenza case status and week of enrollment
Figure 3
Figure 3
Effectiveness of ccIIV by influenza type and subtype and age group. Abbreviations: ccIIV, quadrivalent cell culture-based inactivated influenza vaccine; CI, confidence interval; N, sample size; n, number. 1All models were adjusted for age (spline for all ages and adult models, single year of age for pediatric age groups) and calendar time (pre-peak, peak, and post-peak). Influenza A/H3N2 models also adjusted for COVID-19 vaccine receipt after September 1, 2023; influenza B models also adjusted for COVID-19 vaccine receipt after September 1, 2023, and presence of ≥ 1 high-risk medical condition

References

    1. Rolfes MA, Foppa IM, Garg S et al. Annual estimates of the burden of seasonal influenza in the United States: a tool for strengthening influenza surveillance and preparedness. Influenza Other Respir Viruses 2018;12:132–137. 10.1111/irv.12486 - DOI - PMC - PubMed
    1. Boikos C, Sylvester GC, Sampalis JS, Mansi JA. Relative effectiveness of the cell-cultured quadrivalent influenza vaccine compared to standard, egg-derived quadrivalent influenza vaccines in preventing influenza-like illness in 2017-2018. Clin Infect Dis 2020;71:e665–e671. 10.1093/cid/ciaa371 - DOI - PMC - PubMed
    1. DeMarcus L, Shoubaki L, Federinko S. Comparing influenza vaccine effectiveness between cell-derived and egg-derived vaccines, 2017-2018 influenza season. Vaccine 2019;37:4015–4021. 10.1016/j.vaccine.2019.06.004 - DOI - PubMed
    1. Izurieta HS, Chillarige Y, Kelman J et al. Relative effectiveness of cell-cultured and egg-based influenza vaccines among elderly persons in the United States, 2017-2018. J Infect Dis 2019;220:1255–1264. 10.1093/infdis/jiy716 - DOI - PubMed
    1. Stein AN, Mills CW, McGovern I et al. Relative vaccine effectiveness of cell- vs egg-based quadrivalent influenza vaccine against test-confirmed influenza over 3 seasons between 2017 and 2020 in the United States. Open Forum Infect Dis 2024;11:ofae175. 10.1093/ofid/ofae175 - DOI - PMC - PubMed

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