Cost-effectiveness of measles outbreak intervention strategies

Lessons from past pandemics: a systematic review of evidence-based, cost-effective interventions to suppress COVID-19

BACKGROUND

In an unparalleled global response, during the COVID-19 pandemic, 90 countries asked 3.9 billion people to stay home. Yet other countries avoided lockdowns and focused on other strategies, like contact tracing. How effective and cost-effective are these strategies? We aimed to provide a comprehensive summary of the evidence on past pandemic controls, with a focus on cost-effectiveness.

METHODS

Following PRISMA guidelines, MEDLINE (1946 to April week 2, 2020) and EMBASE (1974 to April 17, 2020) were searched using a range of terms related to pandemic control. Articles reporting on the effectiveness or cost-effectiveness of at least one intervention were included.

RESULTS

We found 1653 papers; 62 were included. The effectiveness of hand-washing and face masks was supported by randomized trials. These measures were highly cost-effective. For other interventions, only observational and modelling studies were found. They suggested that (1) the most cost-effective interventions are swift contact tracing and case isolation, surveillance networks, protective equipment for healthcare workers, and early vaccination (when available); (2) home quarantines and stockpiling antivirals are less cost-effective; (3) social distancing measures like workplace and school closures are effective but costly, making them the least cost-effective options; (4) combinations are more cost-effective than single interventions; and (5) interventions are more cost-effective when adopted early. For 2009 H1N1 influenza, contact tracing was estimated to be 4363 times more cost-effective than school closure ($2260 vs. $9,860,000 per death prevented).

CONCLUSIONS AND CONTRIBUTIONS

For COVID-19, a cautious interpretation suggests that (1) workplace and school closures are effective but costly, especially when adopted late, and (2) scaling up as early as possible a combination of interventions that includes hand-washing, face masks, ample protective equipment for healthcare workers, and swift contact tracing and case isolation is likely to be the most cost-effective strategy.

How to hold an ethical pox party

Pox parties are a controversial alternative to vaccination for diseases such as chickenpox. Such parties involve parents infecting non-immune children by exposing them to a contagious child. If successful, infection will usually lead to immunity, thus preventing infection later in life, which, for several vaccine-preventable diseases, is more severe than childhood infection. Some may consider pox parties more morally objectionable than opting out of vaccination through non-medical exemptions. In this paper, I argue that this is not the case. Pox parties involve immediate risk of harm for children and reduce future harms, whereas opting out of vaccination places children at long-term risk of harms that increase with time, at least for some pathogens. Regarding harm to others through onward transmission of infection, this can be easily prevented in the case of pox parties-given the relatively controlled timing of infection-by quarantining attendees after the party, whereas opting out of vaccination involves risks to others that are more difficult to control. I defend three criteria for an ethical pox party: (1) that the disease is sufficiently low risk, (2) that parents consent to their child's attendance and (3) that children exposed to infection are quarantined and isolated appropriately. I argue that, if these criteria are met, pox parties are morally preferable to non-vaccination; such parties involve less risk to non-consenting others and, for some pathogens in some cases, even involve less risk for the children who participate. Thus, policies that permit non-medical exemption to vaccination should also permit ethical pox parties. Alternatively, if pox parties are not permitted, then vaccination should be mandated for those without medical contraindication.

Framework for Optimal Global Vaccine Stockpile Design for Vaccine-Preventable Diseases: Application to Measles and Cholera Vaccines as Contrasting Examples

Managing the dynamics of vaccine supply and demand represents a significant challenge with very high stakes. Insufficient vaccine supplies can necessitate rationing, lead to preventable adverse health outcomes, delay the achievements of elimination or eradication goals, and/or pose reputation risks for public health authorities and/or manufacturers. This article explores the dynamics of global vaccine supply and demand to consider the opportunities to develop and maintain optimal global vaccine stockpiles for universal vaccines, characterized by large global demand (for which we use measles vaccines as an example), and nonuniversal (including new and niche) vaccines (for which we use oral cholera vaccine as an example). We contrast our approach with other vaccine stockpile optimization frameworks previously developed for the United States pediatric vaccine stockpile to address disruptions in supply and global emergency response vaccine stockpiles to provide on-demand vaccines for use in outbreaks. For measles vaccine, we explore the complexity that arises due to different formulations and presentations of vaccines, consideration of rubella, and the context of regional elimination goals. We conclude that global health policy leaders and stakeholders should procure and maintain appropriate global vaccine rotating stocks for measles and rubella vaccine now to support current regional elimination goals, and should probably also do so for other vaccines to help prevent and control endemic or epidemic diseases. This work suggests the need to better model global vaccine supplies to improve efficiency in the vaccine supply chain, ensure adequate supplies to support elimination and eradication initiatives, and support progress toward the goals of the Global Vaccine Action Plan.

Systematic Review of Health Economic Analyses of Measles and Rubella Immunization Interventions

Economic analyses for vaccine-preventable diseases provide important insights about the value of prevention. We reviewed the literature to identify all of the peer-reviewed, published economic analyses of interventions related to measles and rubella immunization options to assess the different types of analyses performed and characterize key insights. We searched PubMed, the Science Citation Index, and references from relevant articles for studies in English and found 67 analyses that reported primary data and quantitative estimates of benefit-cost or cost-effectiveness analyses for measles and/or rubella immunization interventions. We removed studies that we characterized as cost-minimization analyses from this sample because they generally provide insights that focused on more optimal strategies to achieve the same health outcome. The 67 analyses we included demonstrate the large economic benefits associated with preventing measles and rubella infections using vaccines and the benefit of combining measles and rubella antigens into a formulation that saves the costs associated with injecting the vaccines separately. Despite the importance of population immunity and dynamic viral transmission, most of the analyses used static models to estimate cases prevented and characterize benefits, although the use of dynamic models continues to increase. Many of the analyses focused on characterizing the most significant adverse outcomes (e.g., mortality for measles, congenital rubella syndrome for rubella) and/or only direct costs, and the most complete analyses present data from high-income countries.

Measles outbreak in an asylum-seekers' shelter in Germany: comparison of the implemented with a hypothetical containment strategy

In order to contain a measles outbreak in a German asylum-seekers' shelter, serological testing of all residents was performed, followed by selective vaccination of those with negative test results/not tested. In this paper we describe the outbreak epidemiologically and then compare the implemented strategy with a hypothetical mass vaccination of all individuals unvaccinated or with unknown vaccination status born after 1970 as recommended by the German Standing Committee on Vaccination in terms of potentially avoided cases, logistics, and costs. Three hundred (70%) residents participated in the serological testing, of which 39 (13%) were seronegative. In total, 144 individuals were eligible for vaccination, while a mass vaccination would have targeted 359 persons. However, serological testing was time- and personnel consuming and revealed several logistical problems. Its costs amounted to €90 000, double that of mass vaccination that additionally might have avoided three of the eight cases. Mass vaccination seems the preferred measure for measles outbreak control in such settings.

The use of modeling in the economic evaluation of vaccines

As a consequence of the increased role of pharmacoeconomics in policy-making, economic evaluations are performed at more and more early stages in the development of a therapeutic. This implies the development of models to assess the future impact of an intervention and to account for the level of uncertainty in the associated parameters. This also applies for economic evaluations of vaccines, where not only progression of disease and associated costs are important, but the transmission of the causing agent in the target population also has to be modelled. In this review, we provide an overview of the models that have been used in recent publications on the pharmacoeconomics of vaccines and go deeper into some of the methodological issues associated with the use of models in the economic evaluation of vaccines.

How do government health departments in Australia access health economics advice to inform decisions for health? A survey

Background

Government anticipates that health economic analysis will contribute to evidence-based policy development. Early examples in Australia where this expectation has been met include the economic evaluations of breast and cervical screening. However, the level of integration of health economics within health services that require this advice appears uneven. We sought to describe how government health departments in Australia use specialist health economic advice to inform policy and planning and the mechanisms through which they access this advice.

Methods

Information describing the arrangements for gaining health economics input into health decision-making was sought through interviews with a purposeful sample of economists and non-economists employed by all departments of health in Australia (state, territories and national). The survey was undertaken in August 2004. To aid interpretation of the results eight health economic functions were identified. As a comparison, four other government departments in NSW provided information about their access to economic advice.

Results

All health departments except one reported being current users of health economics expertise. A variety of arrangements were described to source this, from building organisational capacity with self-sufficient in-house units to forging links with external sources. However, specialist positions for economists or health economists employed within health were few. A framework mapping these arrangements for sourcing advice with the eight common health economic functions to be met is presented. All other non-health government departments approached accessed economic advice, with three having in-house units.

Discussion

A small health economics capacity in Australia has been established over the past 30 years through a variety of structural and strategic mechanisms. Health departments value health economic advice and use a variety of arrangements to obtain this. These arrangements have strengths and weaknesses depending upon the task to be undertaken. The lack of uniformity of approach suggests that health departments are still seeking the best ways to incorporate this form of specialist advice into mainstream decision-making.

Implications

Summarises ways that governments source specialist services. Demonstrates how to describe an organisation's need for specialist services as a set of functions. This approach could be applied to assessing need for other specialist areas of advice.

The average cost of measles cases and adverse events following vaccination in industrialised countries

BACKGROUND

Even though the annual incidence rate of measles has dramatically decreased in industrialised countries since the implementation of universal immunisation programmes, cases continue to occur in countries where endemic measles transmission has been interrupted and in countries where adequate levels of immunisation coverage have not been maintained. The objective of this study is to develop a model to estimate the average cost per measles case and per adverse event following measles immunisation using the Netherlands (NL), the United Kingdom (UK) and Canada as examples.

METHODS

Parameter estimates were based on a review of the published literature. A decision tree was built to represent the complications associated with measles cases and adverse events following immunisation. Monte-Carlo Simulation techniques were used to account for uncertainty.

RESULTS

From the perspective of society, we estimated the average cost per measles case to be US$276, US$307 and US$254 for the NL, the UK and Canada, respectively, and the average cost of adverse events following immunisation per vaccinee to be US$1.43, US$1.93 and US$1.51 for the NL, UK and Canada, respectively.

CONCLUSIONS

These average cost estimates could be combined with incidence estimates and costs of immunisation programmes to provide estimates of the cost of measles to industrialised countries. Such estimates could be used as a basis to estimate the potential economic gains of global measles eradication.