Cost-effectiveness of the adjuvanted quadrivalent influenza vaccine in the elderly Belgian population

ABSTRACT

Background

Between 2015 and 2019, when 62% of Belgian adults aged ≥65 years were vaccinated with standard quadrivalent influenza vaccines, influenza caused an average of 3,905 hospitalizations and 347 premature deaths per year in older adults. The objective of the present analysis was to estimate the cost-effectiveness of the adjuvanted quadrivalent influenza vaccine (aQIV) compared to the standard (SD-QIV) and high-dose (HD-QIV) vaccines in elderly Belgians.

Research Design and Methods

The analysis was based on a static cost-effectiveness model that captured the evolution of patients infected with influenza and was customized with available national data.

Results

Vaccinating adults aged ≥65 years with aQIV instead of SD-QIV would decrease the number of hospitalizations by 530 and the number of deaths by 66 in the 2023–2024 influenza season. aQIV was cost-effective compared to SD-QIV with an incremental cost of €15,227/quality-adjusted life year (QALY). aQIV is cost-saving when compared to HD-QIV in the subgroup of institutionalized elderly adults who were granted reimbursement for this vaccine.

Conclusion

In a health care system striving to improve the prevention of infectious diseases, a cost-effective vaccine such as aQIV is a key asset to reduce the number of influenza-related hospitalizations and premature deaths in older adults.

Plain Language Summary

Many older Belgians who get the flu are likely to go to hospital or even die. Some flu vaccines have been specially designed for adults 65 years old and older including one that contains a higher amount of flu particles and another that contains a unique additive called an adjuvant. Both vaccines improve the body’s response to flu infection, but the adjuvanted vaccine is not yet available in Belgium. We used an economic model to compare hypothetical medical spending on Belgians who were vaccinated with the adjuvanted flu vaccine, the high dose flu vaccine, and a standard flu vaccine. We found that the adjuvanted vaccine would reduce flu hospitalizations and deaths in the elderly, which would in turn reduce medical spending on influenza in Belgium.

KEYWORDS:

• adjuvanted quadrivalent vaccine
• cost-effectiveness
• elderly
• influenza
• influenza disease burden

Acknowledgments

The authors acknowledge the support given by Professor Dr. Willy Peetermans, infectiologist at University Hospital UZ Leuven, Belgium, and Professor Dr. Bert Vaes, general practitioner, Belgium, for the review of the model components, inputs and draft paper. The authors also acknowledge the support given by Germaine Hanquet, independent epidemiologist, Belgium, for the review of the model components and inputs. Medical consultant C. Gordon Beck provided editorial support for the final manuscript which was funded by CSL Seqirus.

Declaration of interest

S Marbaix was contracted by CSL Seqirus U.S.A Inc. to conduct this study and organize panel discussion with epidemiological and clinical experts. JF Mould-Quevedo is employed by CSL Seqirus and a shareholder of CSL Limited. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

One reviewer was previously an employee of Seqirus. The remaining reviewers have no other relevant financial relationships or otherwise to disclose.

Author contribution statement

Conception and design: JF Mould-Quevedo and S Marbaix; analysis and interpretation of the data: S Marbaix and JF Mould-Quevedo; Drafting of the paper or revising it critically for intellectual content: S Marbaix, N Dauby, JF Mould-Quevedo; Final approval of the version to be published: S Marbaix, N Dauby, JF Mould-Quevedo. All authors agreed to be accountable for all aspects of the work.

Data availability statement

All data used (except price of aQIV) in this analysis are publicly available from the sources cited in Table 1.

Additional information

Funding

This paper was funded by Seqirus CSL.