Assessment of Public Health and Economic Impact of Intranasal Live-Attenuated Influenza Vaccination of Children in France Using a Dynamic Transmission Model

Background: The goal of this study was to project the number of COVID-19 cases and demand for acute hospital resources for Fall of 2021 in a representative mid-sized community in southwestern Ontario. We sought to evaluate whether current levels of vaccine coverage and contact reduction could mitigate a potential 4th wave fueled by the Delta variant, or whether the reinstitution of more intense public health measures will be required. Methods: We developed an age-stratified dynamic transmission model of COVID-19 in a mid-sized city (population 500,000) currently experiencing a relatively low, but increasing, infection rate in Step 3 of Ontario's Wave 3 recovery. We parameterized the model using the medical literature, grey literature, and government reports. We estimated the current level of contact reduction by model calibration to cases and hospitalizations. We projected the number of infections, number of hospitalizations, and the time to re-instate high intensity public health measures over the fall of 2021 under different levels of vaccine coverage and contact reduction. Results: Maintaining contact reductions at the current level, estimated to be a 17% reduction compared to pre-pandemic contact levels, results in COVID-related admissions exceeding 20% of pre-pandemic critical care capacity by late October, leading to cancellation of elective surgeries and other non-COVID health services. At high levels of vaccination and relatively high levels of mask wearing, a moderate additional effort to reduce contacts (30% reduction compared to pre-pandemic contact levels), is necessary to avoid re-instating intensive public health measures. Compared to prior waves, the age distribution of both cases and hospitalizations shifts younger and the estimated number of pediatric critical care hospitalizations may substantially exceed 20% of capacity. Discussion: High rates of vaccination coverage in people over the age of 12 and mask wearing in public settings will not be sufficient to prevent an overwhelming resurgence of COVID-19 in the Fall of 2021. Our analysis indicates that immediate moderate public health measures can prevent the necessity for more intense and disruptive measures later.

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The epidemiological and economic impact of a cell-based quadrivalent influenza vaccine in an adult population in the US: a dynamic modeling approach

10.21203/rs.3.rs-27872/v1 ◽

2020 ◽

Author(s):

Van Hung Nguyen ◽

Yvonne Hilsky ◽

Joaquin Mould-Quevedo

Keyword(s):

Public Health ◽

Cost Saving ◽

Influenza Vaccine ◽

Economic Impact ◽

Adult Population ◽

Vaccine Effectiveness ◽

Transmission Model ◽

Life Years ◽

A Cell ◽

Quadrivalent Influenza Vaccine

Abstract BackgroundMutations of the H3N2 vaccine strain during the egg-based vaccine manufacturing process seem to partly explain the suboptimal effectiveness of traditional seasonal influenza vaccine. Cell-based influenza vaccines avoid such egg-adaptation, thereby improving antigenic match and vaccine effectiveness. The objective of this study was to evaluate the public health and economic impact of a cell-based quadrivalent influenza vaccine (QIVc) in adult population (18–64 years) compared to the standard egg-based quadrivalent influenza vaccine (QIVe), in the US.MethodsThe impact of QIVc over QIVe in terms of public health and costs outcomes was estimated using a dynamic SEIR transmission model. The model is age-structured and accounts for 4 circulating influenza strains (A/H1N1pdm9, A/H3N2, B(Victoria), and B(Yamagata)). It was calibrated on US attack rate and strain circulation for the seasons 2013–2018. US specific absolute vaccine effectiveness for QIVe, specific hospitalization rate, mortality rate, Quality-Adjusted Life Years (QALYs) and costs were extracted from published literature. Relative vaccine effectiveness of QIVc over QIVe for subjects 18–64 years of age was obtained from a US retrospective cohort study. Robustness of the results was assessed in univariate and probabilistic sensitivity analyses.ResultsSwitching from QIVe to QIVc in the 18–64 year-old population may prevent 5.7 M symptomatic cases, 1.8 M outpatient visits; 50K hospitalizations and 5,453 deaths annually. The switch could save 128 K QALYs and US$ 845M in direct costs, resulting in a cost-saving alternative in a 3-year time horizon analysis. Probabilistic sensitivity analyses confirmed the robustness of the cost-saving result.ConclusionsThe analysis shows that QIVc is expected to prevent a substantial number of hospitalizations and deaths, and would result in substantial savings in health care costs.

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Translation of the UK Pediatric Influenza Vaccination Programme in Primary Schools to 13 European Countries Using a Dynamic Transmission Model

Journal of Health Economics and Outcomes Research ◽

10.36469/9802 ◽

2017 ◽

Vol 5 (1) ◽

pp. 109-124

Author(s):

Laetitia Gerlier ◽

Judith Hackett ◽

Richard Lawson ◽

Sofia Dos Santos Mendes ◽

Martin Eichner

Keyword(s):

United Kingdom ◽

Primary School ◽

Influenza Vaccination ◽

Vaccination Programme ◽

European Countries ◽

Transmission Model ◽

Icu Admission ◽

The United Kingdom ◽

Dynamic Transmission Model ◽

The Uk

Objectives: To simulate the impact of a pediatric influenza vaccination programme using quadrivalent live attenuated influenza vaccine (QLAIV) in Europe by applying coverage rates achieved in the United Kingdom during the 2014–2015 season and to compare the model outcomes to the UK results. Methods: We used a deterministic, age-structured, dynamic transmission model adapted to the demography, contact patterns and influenza incidence of 13 European countries, with a 10-year horizon. The reference strategy was the unchanged country-specific coverage rate, using quadrivalent inactivated vaccine (assumed efficacy against infection from 45% in 1-year-old children to 60% in healthy adults). In the evaluated strategy, 56.8% of 5–10-year-old children were additionally vaccinated with QLAIV (assumed efficacy 80%), as was the case in 2014–2015 in the United Kingdom’s primary school pilot areas. Symptomatic influenza cases and associated medical resources (primary care consultations [PCC], hospitalization, intensive care unit [ICU] admissions) were calculated. The evaluated versus reference strategies were compared using odds ratios (ORs) for PCC in the target (aged 5–10-years) and non-target adult (aged >17 years) populations as well as number needed to vaccinate (NNV) with QLAIV to avert one PCC, hospitalization or ICU admission. Model outcomes, averaged over 10 seasons, were compared with published real-life data from the United Kingdom for the 2014–2015 season. Results: Over 13 countries and 10 years, the evaluated strategy prevented 32.8 million of symptomatic influenza cases (172.3 vs 205.2 million). The resulting range of ORs for PCC was 0.18–0.48 among children aged 5–10-years, and the published OR in the United Kingdom was 0.06 (95% confidence interval [0.01; 0.62]). In adults, the range of ORs for PCC was 0.60–0.91 (UK OR=0.41 [0.19; 0.86]). NNV ranges were 6–19 per averted PCC (UK NNV=16), 530–1524 per averted hospitalization (UK NNV=317) and 5298–15 241 per averted ICU admission (UK NNV=2205). Conclusions: Across a range of European countries, our model shows the beneficial direct and indirect impact of a paediatric vaccination programme using QLAIV in primary school-aged children, consistent with what was observed during a single season in the United Kingdom. Recommendations for the implementation of pediatric vaccination programmes are, therefore, supported in Europe.

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