Data From 5 Studies Show Benefit of Cell-Based Influenza Vaccines

Five studies presented at IDWeek 2024 showed the benefits and importance of seasonal influenza vaccination for individuals aged 6 months to 64 years, reinforcing the benefits of cell-based vaccines.¹

"Evidence shows that higher influenza vaccination rates significantly reduce serious health consequences, including severe illness, hospitalizations, and death. These data underscore an urgent call to action to increase vaccination rates to at least 45% to avoid overburdening our health systems and ensure that our hospital resources, especially [intensive care unit] beds, are not overwhelmed,” Joaquin Mould-Quevedo, global health economic and value strategy senior director at CSL Seqirus, said in a news release.¹

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In the first study titled, “The Impact of Low Influenza Immunization Rates on US Hospital System Resources. A Dynamic Model Estimation,” investigators used an age-stratified transmission model of data from the 2011­–2012 and 1017–2018 influenza seasons The model estimated the impact of low vaccination rates on disease burden as well as hospital resources, evaluating 11 vaccination rates: 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65% and 70%. Available ICU hospital beds was estimated as 30,000 and acute hospitalizations was estimated as 300,000. Investigators concluded that a vaccination of at least 45% is essential to manage health outcomes and hospital burden, especially in the ICU.²

In another study titled, “Relative Vaccine Effectiveness of Cell-Based Versus Egg-Based Quadrivalent Influenza Vaccines Against Test-Confirmed Influenza in the United States 2022-23 Influenza Season,” investigators evaluated a cell-based quadrivalent influenza vaccine and an egg-based cell-based quadrivalent influenza vaccine for those aged 6 months to 64 years. Individuals were vaccinated in 2022–2023 and had a flue test in routine outpatient care within 7 days of a documented acute respiratory or febrile illness. They included 43,089 individuals who tested positive, with 18.6% receiving the cell-based vaccine and 81.4% receiving the egg-based vaccine. Investigators found that the cell-based vaccine was generally more effective than the egg-based vaccine, including relative effectiveness for the study population.²

In the third study, titled “Relative Effectiveness of Cell-Based Influenza Vaccines versus Egg-Based Influenza Vaccines: A Review of Test-Confirmed and Clinical Diagnosis-Based Outcomes,” investigators identified 10 studies that reported on the relative vaccine effectiveness of a cell-based and an egg-based vaccine for those aged 4 to 64 years. Data was included between January 2016 to February 2022, with additional studies from February 2022 to March 2024. According to the results, the pooled relative vaccine effectiveness showed benefits for a cell-based vaccine with estimated of 11.9% for 2017-2018, 11.8% for 2018-2019, 10% for 2019 to 2020 for preventing test-confirmed influenza. Additionally, the estimates were 18.7%, 5.9%, and 10.1%, respectively, in preventing clinically diagnosed influenza.²

In a fourth study titled, “Estimated Additional Burden Averted for the 2022-2023 influenza season from Use of Cell-Based Influenza Vaccines Compared to Egg-Based Influenza Vaccines Among People 0-64 Years of Age in the United States,” investigators analyzed the burden averted due to vaccination using a CDC modeling method for data from 2022-2023, including vaccine uptake, influenza incidence, influenza-related health care resource use, and death. The results showed that the use of ccIIV4 (Flucelvax Quadrivalent; Seqirus) compared with IIV4 adverted an additional 622,826 symptomatic cases, 307,682 outpatient visits, 3,680 hospitalizations, 559 intensive care unit admissions, and 127 deaths.²

In the final study, “A Clinical and Economic Comparison of Non-Egg Influenza Vaccines in Adults 18-64 Years in the US,” investigators used a compartmental dynamic transmission model, including data from individuals aged 18 to 64 years, to help estimate the clinical and economic impact of the cell-based vaccine compared with the recombinant-based vaccine for 1 influenza season. Data was taken from the CDC database and observational studies in the US, including vaccine effectiveness against outpatient visits and hospitalization. The results showed the cell-based vaccine had fewer patient visits and emergency department visits compared with the recombinant-based vaccines. Further, there were comparable numbers of hospitalizations, but the cell-based vaccine showed higher overall quality-adjusted life years and a reduction in an estimated $2.9 billion.²

“The results from these studies, collected and analyzed over several recent influenza seasons, have shown that cell-based influenza vaccines are effective in preventing both test-confirmed and clinically diagnosed influenza,” Mendel Haag, senior director of Center of Outcomes Research & Epidemiology at CSL Seqirus, said in a news release. “This real-world evidence underscores the critical role of cell-based influenza vaccines in improving public health outcomes and easing the burden on health care systems during flu seasons.”¹

REFERENCES

1. CSL Seqirus Presents Data at IDWeek 2024 Highlighting the Urgent Need to Increase Influenza Vaccination Rates and the Benefits of Cell-Based Influenza Vaccines. News release. CSL Seqirus. October 16, 2024. Accessed October 21, 2024. https://www.cslseqirus.us/news/csl-seqirus-presents-data-at-idweek-2024

2. About The Studies Presented at IDWeek 2024. News release. CSL Seqirus. October 2024. Accessed October 21, 2024. https://www.cslseqirus.us/news/csl-seqirus-presents-data-at-idweek-2024