Health and economic impact of seasonal influenza mass vaccination strategies in European settings: A mathematical modelling and cost-effectiveness analysis

• Published in: Vaccine Vol. 40; no. 9; pp. 1306 - 1315
• Main Authors: Sandmann, Frank G., van Leeuwen, Edwin, Bernard-Stoecklin, Sibylle, Casado, Itziar, Castilla, Jesús, Domegan, Lisa, Gherasim, Alin, Hooiveld, Mariëtte, Kislaya, Irina, Larrauri, Amparo, Levy-Bruhl, Daniel, Machado, Ausenda, Marques, Diogo F.P., Martínez-Baz, Iván, Mazagatos, Clara, McMenamin, Jim, Meijer, Adam, Murray, Josephine L.K., Nunes, Baltazar, O'Donnell, Joan, Reynolds, Arlene, Thorrington, Dominic, Pebody, Richard, Baguelin, Marc
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 23.02.2022; Elsevier Limited; Elsevier Science
• Subjects: Age; Age groups; Aged; Child; Collaboration; Cost analysis; Cost benefit analysis; Economic evaluation; Economic impact; Health care; Hospitalization; Humans; Impact analysis; Infections; Influenza; Influenza Vaccines; Influenza, Human - epidemiology; Influenza, Human - prevention & control; Mass Vaccination; Mathematical model; Mathematical models; Middle Aged; Mortality; Older people; Pediatrics; Policy; Population; Prices; Primary care; Public health; Quality-Adjusted Life Years; Seasons; Vaccination; Vaccines; Europe; Policy; Mathematical model; Influenza; Vaccination; Public health; Economic evaluation
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/j.vaccine.2022.01.015

•Seasonal influenza vaccine programmes usually target at-risk and older individuals.•We used an age-structured dynamic-transmission model for eight European settings.•Older people benefit from adjuvanted or high-dose trivalent or quadrivalent vaccines.•Adopting mass paediatric influenza vaccination is also likely to be cost-effective.•Results rest on vaccine costs, willingness to vaccinate and unknown long-term effects. Despite seasonal influenza vaccination programmes in most countries targeting individuals aged ≥ 65 (or ≥ 55) years and high risk-groups, significant disease burden remains. We explored the impact and cost-effectiveness of 27 vaccination programmes targeting the elderly and/or children in eight European settings (n = 205.8 million). We used an age-structured dynamic-transmission model to infer age- and (sub-)type-specific seasonal influenza virus infections calibrated to England, France, Ireland, Navarra, The Netherlands, Portugal, Scotland, and Spain between 2010/11 and 2017/18. The base-case vaccination scenario consisted of non-adjuvanted, non-high dose trivalent vaccines (TV) and no universal paediatric vaccination. We explored i) moving the elderly to “improved” (i.e., adjuvanted or high-dose) trivalent vaccines (iTV) or non-adjuvanted non-high-dose quadrivalent vaccines (QV); ii) adopting mass paediatric vaccination with TV or QV; and iii) combining the elderly and paediatric strategies. We estimated setting-specific costs and quality-adjusted life years (QALYs) gained from the healthcare perspective, and discounted QALYs at 3.0%. In the elderly, the estimated numbers of infection per 100,000 population are reduced by a median of 261.5 (range across settings: 154.4, 475.7) when moving the elderly to iTV and by 150.8 (77.6, 262.3) when moving them to QV. Through indirect protection, adopting mass paediatric programmes with 25% uptake achieves similar reductions in the elderly of 233.6 using TV (range: 58.9, 425.6) or 266.5 using QV (65.7, 477.9), with substantial health gains from averted infections across ages. At €35,000/QALY gained, moving the elderly to iTV plus adopting mass paediatric QV programmes provides the highest mean net benefits and probabilities of being cost-effective in all settings and paediatric coverage levels. Given the direct and indirect protection, and depending on the vaccine prices, model results support a combination of having moved the elderly to an improved vaccine and adopting universal paediatric vaccination programmes across the European settings.