Evaluating the Individual Healthcare Costs and Burden of Disease Associated with RSV Across Age Groups.

BACKGROUND: Respiratory syncytial virus (RSV) is a major cause of acute respiratory infection (ARI), with high morbidity and mortality worldwide. RSV costing and burden estimates can highlight the potential benefits of future vaccination programs and are essential for economic evaluations. OBJECTIVE: We aimed to determine RSV healthcare costs across age groups and the overall disease burden of medically attended RSV in Canada. METHODS: We conducted a retrospective case-control study to estimate the attributable healthcare costs per RSV case in Alberta. We used two case definitions to capture diversity in case severity: laboratory-confirmed RSV and ARI attributable to RSV. Matching occurred on five criteria: (1) age, (2) urban/rural status, (3) sex, (4) prematurity and (5) Charlson Comorbidity Index score. We calculated the age-specific burden of medically attended RSV in Canada from 2010 to 2019 by multiplying the weekly age-specific incidence of medically attended ARI with the RSV positivity rate. RESULTS: Costs per laboratory-confirmed RSV case were (in Canadian dollars [CAD], year 2020 values) $CAD12,713 and 40,028 in the first 30 and 365 days following diagnosis, respectively, whereas a case of ARI potentially attributable to RSV cost $CAD316 and 915, in 30 and 365 days, respectively. Older (aged ≥ 65 years) and younger (aged < 90 days) age groups had the highest case costs. The average medically attended RSV incidence rate across nine seasons was 1743 cases per 100,000 people per year. CONCLUSIONS: RSV is a common and expensive infection at the extremes of life, and the development of immunization programs targeting older and younger ages may be important for the reduction of RSV burden and cost.

Pertussis vaccination in pregnancy in Canada: a cost-utility analysis.

BACKGROUND: The Canadian National Advisory Committee on Immunization recommends universal vaccination against pertussis in pregnancy. We assessed the cost-effectiveness of vaccination with tetanus-diphtheria-acellular pertussis (Tdap) vaccine in pregnancy in Canada. METHODS: We conducted a cost-utility analysis comparing a vaccination program to no program corresponding with the 2017 Canadian guideline for economic evaluation from the Canadian Agency for Drugs and Technologies in Health. We developed 2 models - part decision tree, part Markov model - to estimate the long-term cost and quality-adjusted life-years (QALYs) for pregnant women and their infants. We obtained epidemiologic data from 2006 to 2015, and derived costs and utility values from relevant sources. Results were reported in 2019 Canadian dollars. We obtained expected values through probabilistic analysis, with methodologic and structural uncertainty assessed through scenario analyses. The analysis adopted an acquisition price of Tdap vaccine of $12.50, with scenario analysis conducted to identify the threshold price for vaccination to be cost-effective. RESULTS: In the base-case scenario, for every 1000 pregnant women vaccinated, the program would lead to a gain of 0.3 QALYs, occurring solely in infants, at an increased total cost of $12 987, or $44 301 per QALY gained. Based on a threshold of $50 000 per QALY gained, vaccination would have been cost-effective in 6 of the 10 years included in the model (range of incremental costs $20 463-$100 348 per QALY gained). The threshold cost for Tdap vaccine to be cost-effective over the 10-year horizon was $14.03. INTERPRETATION: Based on a threshold of $50 000 per QALY gained, vaccination against pertussis in pregnancy would be cost-effective if the acquisition cost per vaccine were $14.03 or less. Province- and territory-specific analyses should be done to inform local decision-making.

Active surveillance of acute paediatric hospitalisations demonstrates the impact of vaccination programmes and informs vaccine policy in Canada and Australia.

Sentinel surveillance of acute hospitalisations in response to infectious disease emergencies such as the 2009 influenza A(H1N1)pdm09 pandemic is well described, but recognition of its potential to supplement routine public health surveillance and provide scalability for emergency responses has been limited. We summarise the achievements of two national paediatric hospital surveillance networks relevant to vaccine programmes and emerging infectious diseases in Canada (Canadian Immunization Monitoring Program Active; IMPACT from 1991) and Australia (Paediatric Active Enhanced Disease Surveillance; PAEDS from 2007) and discuss opportunities and challenges in applying their model to other contexts. Both networks were established to enhance capacity to measure vaccine preventable disease burden, vaccine programme impact, and safety, with their scope occasionally being increased with emerging infectious diseases' surveillance. Their active surveillance has increased data accuracy and utility for syndromic conditions (e.g. encephalitis), pathogen-specific diseases (e.g. pertussis, rotavirus, influenza), and adverse events following immunisation (e.g. febrile seizure), enabled correlation of biological specimens with clinical context and supported responses to emerging infections (e.g. pandemic influenza, parechovirus, COVID-19). The demonstrated long-term value of continuous, rather than incident-related, operation of these networks in strengthening routine surveillance, bridging research gaps, and providing scalable public health response, supports their applicability to other countries.

Burden of Children Hospitalized With Pertussis in Canada in the Acellular Pertussis Vaccine Era, 1999-2015.

BACKGROUND: Recent increases in pertussis morbidity and mortality rates among young infants have led to a recommendation in some countries for vaccination against pertussis during pregnancy. Having data on the burden of pediatric pertussis in a large population over time is important for establishing the true burden of disease in the acellular pertussis (aP) vaccine era. Here, we describe age-specific epidemiology and morbidity and mortality rates in children hospitalized with pertussis over 17 years across Canada in the aP vaccine era. METHODS: Patients aged ≤16 years who were admitted to 1 of 12 pediatric tertiary-care hospitals across Canada between 1999 and 2015 with confirmed (laboratory-confirmed or epidemiologically linked) or probable (clinically diagnosed) pertussis were included. RESULTS: Overall, 1402 patients with pertussis were included. Infants aged <2 months had the highest mean annual incidences of pertussis hospitalization and intensive care unit (ICU) admission (116.40 [95% confidence interval (CI), 85.32-147.49] and 33.48 [95% CI, 26.35-40.62] per 100 000 population, respectively). The overall proportion of children who required ICU admission was 25.46%, and the proportion was highest in infants aged <2 months (37.90%). Over the span of this study, 21 deaths occurred. Age of <16 weeks, prematurity, encephalopathy, and a confirmed pertussis diagnosis were independent risk factors for ICU admission. Age of <4 weeks, prematurity, and female sex were independent risk factors for death. CONCLUSIONS: In the aP vaccine era, endemic pertussis still contributes considerably to childhood morbidity and death, particularly in infants aged <2 months. Vaccination against pertussis during pregnancy has the potential to reduce this disease burden.

Hospitalization for Influenza A Versus B.

BACKGROUND: The extent to which influenza A and B infection differs remains uncertain. METHODS: Using active surveillance data from the Canadian Immunization Monitoring Program Active at 12 pediatric hospitals, we compared clinical characteristics and outcomes of children ≤16 years admitted with laboratory-confirmed influenza B or seasonal influenza A. We also examined factors associated with ICU admission in children hospitalized with influenza B. RESULTS: Over 8 nonpandemic influenza seasons (2004-2013), we identified 1510 influenza B and 2645 influenza A cases; median ages were 3.9 and 2.0 years, respectively (P < .0001). Compared with influenza A patients, influenza B patients were more likely to have a vaccine-indicated condition (odds ratio [OR] = 1.30; 95% confidence interval [CI] = 1.14-1.47). Symptoms more often associated with influenza B were headache, abdominal pain, and myalgia (P < .0001 for all symptoms after adjustment for age and health status). The proportion of deaths attributable to influenza was significantly greater for influenza B (1.1%) than influenza A (0.4%); adjusted for age and health status, OR was 2.65 (95% CI = 1.18-5.94). A similar adjusted OR was obtained for all-cause mortality (OR = 2.95; 95% CI = 1.34-6.49). Among healthy children with influenza B, age ≥10 years (relative to <6 months) was associated with the greatest odds of ICU admission (OR = 5.79; 95% CI = 1.91-17.57). CONCLUSIONS: Mortality associated with pediatric influenza B infection was greater than that of influenza A. Among healthy children hosptialized with influenza B, those 10 years and older had a significant risk of ICU admission.

Cost effectiveness of infant vaccination for rotavirus in Canada.

INTRODUCTION: Rotavirus is the main cause of gastroenteritis in Canadian children younger than five years of age, resulting in significant morbidity and cost. The present study provides evidence on the cost effectiveness of two alternative rotavirus vaccinations (RotaTeq [Merck Frosst Canada Ltd, Canada] and Rotarix [GlaxoSmithKline, Canada]) available in Canada. METHODS: Analysis was conducted through a Markov model that followed a cohort of children from birth to five years of age. Analysis used pertinent data on the natural history of rotavirus and the effects of vaccination. Estimates of heath care costs for children requiring hospitalizations and emergency department visits were derived from the Canadian Immunization Monitoring Program, Active (IMPACT) surveillance, emergency department studies, as well as other Canadian studies. The model estimated the effect of vaccination on costs and quality-adjusted life years (QALYs). RESULTS: The incremental cost per QALY gained from the health care system perspective was $122,000 for RotaTeq and $108,000 for Rotarix. From the societal perspective, both vaccination strategies were dominant - both cost saving and more effective. The cost-effectiveness of vaccination is dependent on the mode of administration, the perspective adopted and the cost of the vaccine. CONCLUSIONS: From a societal perspective, a universal vaccination program against rotavirus will be both cost saving and more effective than no vaccination. Becasue the majority of rotavirus infections do not require emergency department visits or hospital admission, from a health care system perspective, a program would not be considered cost effective.

INTRODUCTION: Le rotavirus est la principale cause de gastroentérite chez les enfants canadiens de moins de cinq ans, ce qui s'associe à une morbidité et à des coûts considérables. La présente étude expose des données probantes sur le rapport coût-efficacité de deux vaccins contre le rotavirus (RotaTeq [Merck Frosst Canada Ltée, Canada] et Rotarix [GlaxoSmithKline, Canada]) offerts au Canada. MÉTHODOLOGIE: Les chercheurs ont effectué l'analyse au moyen d'un modèle de Markov qui consistait à suivre une cohorte d'enfants entre la naissance et cinq ans. L'analyse faisait appel à des données pertinentes sur l'évolution naturelle du rotavirus et sur les effets de la vaccination. Les évaluations des coûts de santé à l'égard des enfants devant être hospitalisés et consulter à l'urgence étaient tirées de la surveillance du Programme canadien de surveillance active de l'immunisation (IMPACT), d'études des départements d'urgence et d'autres études canadiennes. Le modèle a permis d'évaluer l'effet de la vaccination sur les coûts et les années de vie ajustées en fonction de la qualité (AVAQ). RÉSULTATS: Le coût incrémentiel par AVAQ épargné par le système de santé s'élevait à 122 000 $ à l'aide du vaccin RotaTeq et à 108 000 $ à l'aide du vaccin Rotarix. Sur le plan sociétal, les deux stratégies vaccinales étaient dominantes, c'est-à-dire qu'elles étaient à la fois rentables et plus efficaces. Le rapport coût-efficacité de la vaccination dépend du mode d'administration, de la perspective adoptée et du coût du vaccin. CONCLUSIONS: Sur le plan sociétal, un programme de vaccination universel contre le rotavirus sera à la fois rentable et plus efficace que l'absence de vaccination. Puisque la majorité des infections à rotavirus n'exigent pas de consultation à l'urgence ou d'hospitalisation, le programme ne serait pas rentable pour le système de santé.

Pan-Canadian assessment of pandemic immunization data collection: study methodology.

BACKGROUND: The collection of individual-level pandemic (H1N1) 2009 influenza immunization data was considered important to facilitate optimal vaccine delivery and accurate assessment of vaccine coverage. These data are also critical for research aimed at evaluating the new vaccine's safety and effectiveness. Systems used to collect immunization data include manual approaches in which data are collected and retained on paper, electronic systems in which data are captured on computer at the point of vaccination and hybrid systems which are comprised of both computerized and manual data collection components. This study's objective was to compare the efficiencies and perceptions of data collection methods employed during Canada's pandemic (H1N1) 2009 influenza vaccination campaign. METHODS/DESIGN: A pan-Canadian observational study was conducted in a convenience sample of public health clinics and healthcare institutions during the H1N1 vaccination campaign in the fall of 2009. The study design consisted of three stages: Stage 1 involved passive observation of the site's layout, processes and client flow; Stage 2 entailed timing site staff on 20 clients through five core immunization tasks: i) client registration, ii) medical history collection, iii) medical history review, iv) vaccine administration record keeping and v) preparation of proof of vaccine administration for the client; in Stage 3, site staff completed a questionnaire regarding perceived usability of the site's data collection approach. Before the national study began, a pilot study was conducted in three seasonal influenza vaccination sites in Ontario, to both test that the proposed methodology was logistically feasible and to determine inter-rater reliability in the measurements of the research staff. Comparative analyses will be conducted across the range of data collection methods with respect to time required to collect immunization data, number and type of individual-level data elements collected, and clinic staff perceptions of the usability of the method employed at their site, using analysis of variance (ANOVA). DISCUSSION: Various data collection methods were employed at immunization sites across Canada during the pandemic (H1N1) 2009 influenza vaccination campaign. Our comparison of methods can facilitate planning an efficient, coordinated approach for collecting immunization data in future influenza seasons.