A quantitative assessment of epidemiological parameters required to investigate COVID-19 burden.

Solid estimates describing the clinical course of SARS-CoV-2 infections are still lacking due to under-ascertainment of asymptomatic and mild-disease cases. In this work, we quantify age-specific probabilities of transitions between stages defining the natural history of SARS-CoV-2 infection from 1965 SARS-CoV-2 positive individuals identified in Italy between March and April 2020 among contacts of confirmed cases. Infected contacts of cases were confirmed via RT-PCR tests as part of contact tracing activities or retrospectively via IgG serological tests and followed-up for symptoms and clinical outcomes. In addition, we provide estimates of time intervals between key events defining the clinical progression of cases as obtained from a larger sample, consisting of 95,371 infections ascertained between February and July 2020. We found that being older than 60 years of age was associated with a 39.9% (95%CI: 36.2-43.6%) likelihood of developing respiratory symptoms or fever ≥ 37.5 °C after SARS-CoV-2 infection; the 22.3% (95%CI: 19.3-25.6%) of the infections in this age group required hospital care and the 1% (95%CI: 0.4-2.1%) were admitted to an intensive care unit (ICU). The corresponding proportions in individuals younger than 60 years were estimated at 27.9% (95%CI: 25.4-30.4%), 8.8% (95%CI: 7.3-10.5%) and 0.4% (95%CI: 0.1-0.9%), respectively. The infection fatality ratio (IFR) ranged from 0.2% (95%CI: 0.0-0.6%) in individuals younger than 60 years to 12.3% (95%CI: 6.9-19.7%) for those aged 80 years or more; the case fatality ratio (CFR) in these two age classes was 0.6% (95%CI: 0.1-2%) and 19.2% (95%CI: 10.9-30.1%), respectively. The median length of stay in hospital was 10 (IQR: 3-21) days; the length of stay in ICU was 11 (IQR: 6-19) days. The obtained estimates provide insights into the epidemiology of COVID-19 and could be instrumental to refine mathematical modeling work supporting public health decisions.

[Covid-19 and clinical-epidemiological research in Italy: proposal of a research agenda on priority topics by the Italian association of epidemiology]. / Covid-19 e ricerca clinico-epidemiologica in Italia: proposta di un'agenda di ricerca su temi prioritari da parte dell'Associazione italiana di epidemiologia.

BACKGROUND: the Covid-19 pandemic has provoked a huge of clinical and epidemiological research initiatives, especially in the most involved countries. However, this very large effort was characterized by several methodological weaknesses, both in the field of discovering effective treatments (with too many small and uncontrolled trials) and in the field of identifying preventable risks and prognostic factors (with too few large, representative and well-designed cohorts or case-control studies). OBJECTIVES: in response to the fragmented and uncoordinated research production on Covid-19, the   italian Association of Epidemiology (AIE) stimulated the formation of a working group (WG) with the aims of identifying the most important gaps in knowledge and to propose a structured research agenda of clinical and epidemiological studies considered at high priority on Covid-19, including recommendations on the preferable methodology. METHODS: the WG was composed by 25 subjects, mainly epidemiologists, statisticians, and other experts in specific fields, who have voluntarily agreed to the proposal. The agreement on a list of main research questions and on the structure of the specific documents to be produced were defined through few meetings and cycles of document exchanges. RESULTS: twelve main research questions on Covid-19 were identified, covering aetiology, prognosis, interventions, follow-up and impact on general and specific populations (children, pregnant women). For each of them, a two-page form was developed, structured in: background, main topics, methods (with recommendations on preferred study design and warnings for bias prevention) and an essential bibliography. CONCLUSIONS: this research agenda represents an initial contribution to direct clinical and epidemiological research efforts on high priority topics with a focus on methodological aspects. Further development and refinements of this agenda by Public Health Authorities are encouraged.

The impact of demographic changes, exogenous boosting and new vaccination policies on varicella and herpes zoster in Italy: a modelling and cost-effectiveness study.

BACKGROUND: The present study aims to evaluate the cost-effectiveness of the newly introduced varicella and herpes zoster (HZ) vaccination programmes in Italy. The appropriateness of the introduction of the varicella vaccine is highly debated because of concerns about the consequences on HZ epidemiology and the expected increase in the number of severe cases in case of suboptimal coverage levels. METHODS: We performed a cost-utility analysis based on a stochastic individual-based model that considers realistic demographic processes and two different underlying mechanisms of exogenous boosting (temporary and progressive immunity). Routine varicella vaccination is given with a two-dose schedule (15 months, 5-6 years). The HZ vaccine is offered to the elderly (65 years), either alone or in combination with an initial catch-up campaign (66-75 years). The main outcome measures are averted cases and deaths, costs per quality-adjusted life years gained, incremental cost-effectiveness ratios, and net monetary benefits associated with the different vaccination policies. RESULTS: Demographic processes have contributed to shaping varicella and HZ epidemiology over the years, decreasing varicella circulation and increasing the incidence of HZ. The recent introduction of varicella vaccination in Italy is expected to produce an enduring reduction in varicella incidence and, indirectly, a further increase of HZ incidence in the first decades, followed by a significant reduction in the long term. However, the concurrent introduction of routine HZ vaccination at 65 years of age is expected to mitigate this increase and, in the longer run, to reduce HZ burden to its minimum. From an economic perspective, all the considered policies are cost-effective, with the exception of varicella vaccination alone when considering a time horizon of 50 years. These results are robust to parameter uncertainties, to the two different hypotheses on the mechanism driving exogenous boosting, and to different demographic projection scenarios. CONCLUSIONS: The recent introduction of a combined varicella and HZ vaccination programme in Italy will produce significant reductions in the burden of both diseases and is found to be a cost-effective policy. This programme will counterbalance the increasing trend of zoster incidence purely due to demographic processes.

The missed Constitutional Reform and its possible impact on the sustainability of the Italian National Health Service.

The rejection of the Constitutional Law Bill No.1429-D in the December 2016 referendum, has stimulated a cause for reflection on current health legislation and the future prospects of the Italian National Health Service; also in the context of the recent approval of the new Essential Levels of care (LEA) and other relevant laws approved by the Parliament. This article analyzes possible future legislative and organizational scenarios with particular regard to issues related to National health system's sustainability.

[Decisional framework for varicella vaccine: challenges in the face of opportunity]. / Modello decisionale per l'adozione del vaccino antivaricella: una sfida di fattibilità.

INTRODUCTION: Decision makers adopt interventions, including vaccines, which are most beneficial to populations. A transparent, unbiased, and comprehensive framework based on evidence-based criteria is a promising tool to guide decision-making on vaccine adoption: we developed a multi-dimensional framework conceived from the DECIDE - Evidence to decision Framework (EtD framework). We validated the framework by conducting a real data and evidence set collection on varicella vaccination and tested it with a multidisciplinary group. METHODS: The EtD framework presented evidence concerning the varicella vaccination organized in six dimensions: Burden of disease, Vaccine characteristics and impact of immunization program, Values and preferences, Resource use, Equity and Feasibility. Two reviewers completed each dimension with information about varicella vaccine. A multidisciplinary group of 42 participants were asked to evaluate the information in the framework, decide whether to introduce varicella vaccine in the national immunization program, assess the usefulness, and propose some impovements of the decision-making tool. RESULTS: From 33 responders (79%) out of 42, 61% supported the adoption of the varicella vaccine as part of the national immunization program. A half (50%) favored the monovalent vaccine while the other half chose the tetravalent vaccine. About 90% of responders found information in the EtD framework comprehensive, easy to understand, and presented in a way that helped make decisions. CONCLUSIONS: Complete and transparent information are welcome. The EtD identified a situation of important divergences between policy makers regarding the introduction and the choice of vaccine. In our case study, for example, a third of the multidisciplinary group did not recommend the adoption of varicella vaccine.

Health and economic outcomes of introducing the new MenB vaccine (Bexsero) into the Italian routine infant immunisation programme.

INTRODUCTION: In January 2013 a novel type of multicomponent protein-based vaccine against group B meningococcal disease was licensed by the European Medicines Agency. With the widespread use of the meningococcal serogroup C conjugate vaccines, serogroup B remains now the major cause of bacterial meningitis and septicaemia in young children in Europe. The aim of this study is to investigate the health and the economic outcomes of MenB vaccine introduction into the Italian routine mass vaccination programme. METHODS: The present work is structured in two main parts. Firstly, we assess the epidemiological burden of group B meningococcal disease using official hospitalisation and notification data from two of the most populated Italian regions (Lombardia and Piemonte) during a 6-year study period (2007-2012). Secondly, we evaluate the cost-effectiveness of the immunisation programme in Italy from the public health payer perspective under base case parameters assumptions and performing a comprehensive sensitivity analysis to assess the robustness and the uncertainty of our model results. RESULTS: MenB serotype is responsible for 59% of the 341 cases of Invasive Meningococcal Disease in Lombardia and Piemonte. Incidence rate for MenB infection is estimated to be 0.21/100,000/y resulting at the highest level in children ≤4 years of age. Although the new MenB vaccine can potentially prevent about one third of the disease cases in the Italian population, model results show this strategy is unlikely to be cost-effective (ICER value over €350,000/QALY) with a vaccine that prevents disease only. These results are robust under most of the sensitivity scenarios except when allowing for lower discount rates. DISCUSSION: The introduction of the novel vaccine into the routine immunisation schedule needs to be carefully evaluated. The new MenB vaccine has the potential to reduce the disease burden at the population level. However, from the Italian Health Service perspective, the immunisation programme is unlikely to be cost-effective at the current incidence levels and vaccine price.