Beyond efficacy: The full public health impact of vaccines

Quasi-experimental methods for pharmacoepidemiology: difference-in-differences and synthetic control methods with case studies for vaccine evaluation

Difference-in-differences and synthetic control methods have become common study designs for evaluating the effects of changes in policies, including health policies. They also have potential for providing real-world effectiveness and safety evidence in pharmacoepidemiology. To effectively add to the toolkit of the field, however, designs-including both their benefits and drawbacks-must be well understood. Quasi-experimental designs provide an opportunity to estimate the average treatment effect on the treated without requiring the measurement of all possible confounding factors, and to assess population-level effects. This requires, however, other key assumptions, including the parallel trends or stable weighting assumptions, a lack of other concurrent events that could alter time trends, and an absence of contamination between exposed and unexposed units. The targeted estimands are also highly specific to the settings of the study, and combining across units or time periods can be challenging. Case studies are presented for 3 vaccine evaluation studies, showcasing some of these challenges and opportunities in a specific field of pharmacoepidemiology. These methods provide feasible and valuable sources of evidence in various pharmacoepidemiologic settings and can be improved through research to identify and weigh the advantages and disadvantages in those settings. This article is part of a Special Collection on Pharmacoepidemiology.

Economic burden of dengue in urban Bangladesh: A societal perspective

BACKGROUND

Dengue, a vector-borne disease, is a major public health problem in many tropical and subtropical countries including Bangladesh. The objective of this study is to estimate the societal cost of illness of dengue infections among the urban population in Dhaka, Bangladesh.

METHODS

A cost-of-illness study was conducted using a prevalence-based approach from a societal perspective. Costs attributable to dengue were estimated from a bottom-up strategy using the guideline proposed by the World Health Organization for estimating the economic burden of infectious diseases.

RESULTS

A total of 302 hospitalized confirmed dengue patients were enrolled in this study. The average cost to society for a person with a dengue episode was US$ 479.02. This amount was ranged between US$ 341.67 and US$ 567.12 for those patients who were treated at public and private hospitals, respectively. The households out-of-pocket cost contributed to a larger portion of the total costs of illness (66%) while the cost burden was significantly higher for the poorest households than the richest quintile.

CONCLUSIONS

Dengue disease imposes a substantial financial burden on households and society. Therefore, decision-makers should consider the treatment cost of dengue infections, particularly among the poor in the population while balancing the benefits of introducing potentially effective dengue preventive programs in Bangladesh.

Economic evaluations of immunization programs as an indispensable tool for policymakers

Introducing new vaccines within national immunization programs requires careful consideration of disease- and vaccine-related issues as well as of the strength of the program and the affected health system. Economic evaluations play an essential role in this process. In this editorial, we set the context and invite contributions for a BMC Health Services Research Collection of articles titled 'Economic Evaluations of Vaccine Programs'.

Vaccine hesitancy in Malawi: a threat to already-made health gains

Malawi faces a growing concern about vaccine hesitancy. This threatens to undermine significant strides in the fight against infectious diseases in the country. Vaccine hesitancy in Malawi is driven by multiple factors. This short communication discusses the extent of vaccine hesitancy in Malawi and its main drivers according to SAGE's (Strategic Advisory Group of Expert) 3Cs (confidence, complacency and convenience) model of vaccine hesitancy. As an escalating health concern, it is imperative to address it urgently. It is imperative to address it urgently through comprehensive and sustainable awareness campaigns that should aim to increase acceptance and demand for vaccines.

Methods to evaluate COVID-19 vaccine effectiveness, with an emphasis on quasi-experimental approaches

The evaluation of vaccine effectiveness is conducted with real-world data. They are essential to monitor the performance of vaccination programmes over time, and in the context of the emergence of new variants. Until now, the effectiveness of COVID-19 vaccines has been assessed based on classic methods, such as cohort and test-negative case-control studies, which may often not allow for adequate control of inherent biases in the assignment of vaccination campaigns. The aim of this review was to discuss the study designs available to evaluate vaccine effectiveness, highlighting quasi-experimental studies, which seek to mimic randomized trials, by introducing an exogenous component to allocate to treatment, in addition to the advantages, limitations, and applicability in the context of Brazilian data. The use of quasi-experimental approaches, such as interrupted time series, difference-in-differences, propensity scores, instrumental variables, and regression discontinuity design, are relevant due to the possibility of providing more accurate estimates of COVID-19 vaccine effectiveness. This is especially important in scenarios such as the Brazilian, which characterized by the use of various vaccines, with the respective numbers and intervals between doses, applied to different age groups, and introduced at different times during the pandemic.

Arboviruses: A global public health threat

A conference on «ARBOVIRUSES, A GLOBAL PUBLIC HEALTH THREAT» was organized on June 20–22, 2018 at the Merieux Foundation Conference Center in Veyrier du Lac, France, to review and raise awareness to the global public health threat of epidemic arboviruses, and to advance the discussion on the control and prevention of arboviral diseases. The presentations by scientists and public health officials from Asia, the Americas, Europe and Africa strengthened the notion that arboviral diseases of both humans and domestic animals are progressively becoming dominant public health problems in the world. The repeated occurrence of recent deadly epidemics strongly reinforces the call for action against these viral diseases, and the need for developing effective vaccines, drugs, vector control tools and strong prevention programs.

How to assess for the full economic value of vaccines? From past to present, drawing lessons for the future

Background:Cost-effectiveness analysis (CEA) is the economic analysis method most commonly applied today in the context of replacing one treatment with a new one in a developed healthcare system to improve efficiency. CEA is often requested by local healthcare decision-makers to grant reimbursement. New preventative interventions, such as new vaccines, may however have much wider benefits inside and outside healthcare, when compared with treatment. These additional benefits include externalities on indirect clinical impact, reallocation of specific healthcare resources, improved quality of care, better productivity, better disease control, better fiscal revenues, and others. But these effects are sometimes difficult to integrate into a meaningful CEA result. They may appear as specific benefits for specific stakeholders, other than the stakeholders in healthcare. Objective: Based on a historical view about the application of economic assessments for vaccines our objective has been to make the inventory of who was/is interested in knowing the economic value of vaccines, in what those different stakeholders are likely to see the benefit from their perspective and how  were/are we able to measure those benefits and to report them well. Results: The historical view disclosed a limited interest in the economic assessment of vaccines at start, more than 50 years ago, that was comparable to the assessment of looking for more efficiency in new industries through optimization exercises. Today, we are exposed to a very rich panoply of different stakeholders (n= 16). They have their specific interest in many different facets of the vaccine benefit of which some are well known in the conventional economic analysis (n=9), but most outcomes are hidden and not enough evaluated and reported (n=26). Meanwhile we discovered that many different methods of evaluation have been explored to facilitate the measurement and reporting of the benefits (n=18). Conclusion: Our recommendation for future economic evaluations of new vaccines is therefore to find the right combination among the three entities of stakeholder type selection, outcome measure of interest for each stakeholder, and the right method to apply. We present at the end examples that illustrate how successful this approach can be.

Why vaccines matter: understanding the broader health, economic, and child development benefits of routine vaccination

The direct benefits of childhood vaccination in reducing the burden of disease morbidity and mortality in a cost-effective manner are well-established. By preventing episodes of vaccine-preventable diseases, vaccination can also help avert associated out-of-pocket medical expenses, healthcare provider costs, and losses in wages of patients and caregivers. Studies have associated vaccines positively with cognition and school attainment, suggesting benefits of long-term improved economic productivity. New evidence suggests that the measles vaccine may improve immunological memory and prevent co-infections, thereby forming a protective shield against other infections, and consequently improving health, cognition, schooling and productivity outcomes well into the adolescence and adulthood in low-income settings. Systematically documenting these broader health, economic, and child development benefits of vaccines is important from a policy perspective, not only in low and middle-income countries where the burden of vaccine-preventable diseases is high and public resources are constrained, but also in high-income settings where the emergence of vaccine hesitancy poses a threat to benefits gained from reducing vaccine-preventable diseases. In this paper, we provide a brief summary of the recent evidence on the benefits of vaccines, and discuss the policy implications of these findings.

Routine infant vaccination of pneumococcal conjugate vaccines has decreased pneumonia across all age groups in Northern Spain

Since the early 2000s, pneumococcal conjugate vaccines (PCVs) have been shown to be effective in the prevention of pneumonia and invasive pneumococcal diseases. In 2011, the Galician region incorporated PCV in the routine infant immunization, the very first stable program in Spain. We aim to assess direct and indirect benefits of PCV vaccination on all-cause pneumonia in the region across different age groups using an ecological study design. For this, we calculated the annual hospitalization rates using a hospital-based disease registry. We identified all-cause pneumonia, pneumococcal pneumonia and pneumococcal invasive diseases within the registry. Hospitalization rates were computed and compared across three study periods: pre-vaccination (1998-2003), early-vaccination (2005-2009) and routine-vaccination (2011-2015). Across Northern Spain, we identified 114,873 all-cause pneumonia hospitalizations, of which 24,808 were further diagnosed with pneumococcal pneumonia. The majority were elderly > 64 years (67.3%). Hospitalizations from all-cause pneumonia had a net increase from 20.6 (pre-PCV) and 21.4/10,000 (early) to 28.4/10,000 (routine) (+32.7%, p < .0001), this is attributed to the huge number of cases in the elderly age group. In contrast, a net reduction of incidence of hospitalized pneumococcal pneumonia was observed from 6.3/10,000 (pre-PCV) and 5.7/10,000 (early) to 2.4/10,000 (routine) cases (-57.9%, p < .0001). Thus, routine infant vaccination may have resulted to an overall decline of pneumococcal pneumonia in infants, as well as in elderly age groups. However, a paradoxical increase on all-cause pneumonia was observed in Galicia, mostly attributed to the growing number of cases in the elderly population.

Public Health-Driven Research and Innovation for Next-Generation Influenza Vaccines, European Union

Influenza virus infections are a major public health threat. Vaccination is available, but unpredictable antigenic changes in circulating strains require annual modification of seasonal influenza vaccines. Vaccine effectiveness has proven limited, particularly in certain groups, such as the elderly. Moreover, preparedness for upcoming pandemics is challenging because we can predict neither the strain that will cause the next pandemic nor the severity of the pandemic. The European Union fosters research and innovation to develop novel vaccines that evoke broadly protective and long-lasting immune responses against both seasonal and pandemic influenza, underpinned by a political commitment to global public health.

Anthropometric, cognitive, and schooling benefits of measles vaccination: Longitudinal cohort analysis in Ethiopia, India, and Vietnam

OBJECTIVE

To estimate the associations between measles vaccination and child anthropometry, cognition, and schooling outcomes in Ethiopia, India, and Vietnam.

METHODS

Longitudinal survey data from Young Lives were used to compare outcomes at ages 7-8 and 11-12 years between children who reported receipt or non-receipt of measles vaccine at 6-18 months-of-life (n = ∼2000/country). Z-scores of height-for-age (HAZ), BMI-for-age (BMIZ), weight-for-age (WAZ), Peabody Picture Vocabulary Test (PPVT), early grade reading assessment (EGRA), language and mathematics tests, and attained schooling grade were examined. Propensity score matching was used to control for systematic differences between measles-vaccinated and measles-unvaccinated children.

FINDINGS

Using age- and country-matched measles-unvaccinated children as comparisons, measles-vaccinated children had better anthropometrics, cognition, and schooling. Measles-vaccinated children had 0.1 higher HAZ in India and 0.2 higher BMIZ and WAZ in Vietnam at age 7-8 years, and 0.2 higher BMIZ at age 11-12 years in Vietnam. At ages 7-8 years, they scored 4.5 and 2.9 percentage points (pp) more on PPVT and mathematics, and 2.3 points more on EGRA in Ethiopia, 2.5 points more on EGRA in India, and 2.6 pp, 4 pp, and 2.7 points more respectively on PPVT, mathematics, and EGRA in Vietnam. At ages 11-12 years, they scored 3 pp more on English and PPVT in India, and 1.7 pp more on PPVT in Vietnam. They also attained 0.2-0.3 additional schooling grades across all ages and countries.

CONCLUSION

Our findings suggest that measles vaccination may have benefits on cognitive gains and school-grade attainment that can have broad educational and economic consequences which extend beyond early childhood.

Building the evidence base for dengue vector control: searching for certainty in an uncertain world

This review discusses biological and chemical methods for dengue vector control, using recently emerging summary evidence, meta-analyses and systematic reviews to conclude on practical public health recommendations for Aedes control, which is increasingly relevant in an era of widespread Chikungunya, yellow feer and Zika outbreaks. The analysis follows an a priori framework of systematic reviews by the authors on vector control methods, distinguishing vector control methods into biological, chemical and environmental methods. Findings of each published systematic review by the authors, following each individual vector control method, are summarised and compared in the discussion against the findings of existing meta-analyses covering all vector control methods. Analysing nine systematic reviews and comparing to two existing meta-analyses provided low-to-moderate evidence that the control of Aedes mosquitoes can be achieved using 1) chemical methods, particularly indoor residual spraying and insecticide treated materials, and 2) biological methods, where appropriate. The level of efficacy and community effectiveness of the methods in most studies analysed is low, as was the overall assessment of study quality. Furthermore, the results show that too optimise results, larvae and adults should be targeted simultaneously. The quality of service delivery is probably one of the most important features of this analysis - and including high coverage. The analysis also highlights the urgent need for standards to guide the design and reporting of vector control studies, ensuring the validity and comparability of results. These studies should aim to include measurements of human transmission data - where and when possible.

Protection of the house against Chagas disease, dengue, leishmaniasis, and lymphatic filariasis: a systematic review

In light of the recent Zika virus outbreak, vector control has received renewed interest. However, which interventions are efficacious and community effective and how to best deliver them remains unclear. Following PRISMA guidelines, we did a systematic review to assess evidence for applied vector control interventions providing protection against Chagas disease, dengue, leishmaniasis, and lymphatic filariasis at the household level. We searched for published literature and grey literature between Jan 1, 1980, and Nov 30, 2015, and updated our search on April 2, 2017, using databases including the Cochrane, Embase, LILACS, PubMed, Web of Science, and WHOLIS. The Cochrane Collaboration's tool for assessing risk of bias was used. Inclusion criteria included studies reporting vector control interventions in and around a house or dwelling; and use of insecticides as sprays on netting or screens, and any method to control larval breeding in water containers in and around the home. 1416 articles were assessed and 32 articles included. The most effective interventions affecting vector indices for multiple diseases were found to be intradomiciliary residual spraying, insecticide-treated materials (especially insecticide-treated nets or curtains), and treatment of larval habitats with biological and chemical methods. Waste management and clean-up campaigns reduce vector populations, although to a lesser extent than other interventions and not consistently. Modifications to the structure of homes (eg, wall plastering) had no impact on the control of vectors. Protection of the house and its surroundings might affect the transmission of several diseases. The most effective interventions should be prioritised when vector control programmes are designed; however, the quality of delivery (ie, coverage and reapplication) of interventions is a crucial factor to ensure their effectiveness. Additional randomised trials that assess the measures of human disease and eventually target several diseases with a combination of interventions that protect the household and its inhabitants against multiple vectors, are needed to inform global policy in this area.

Estimating the full public health value of vaccination

There is an enhanced focus on considering the full public health value (FPHV) of vaccination when setting priorities, making regulatory decisions and establishing implementation policy for public health activities. Historically, a therapeutic paradigm has been applied to the evaluation of prophylactic vaccines and focuses on an individual benefit-risk assessment in prospective and individually-randomized phase III trials to assess safety and efficacy against etiologically-confirmed clinical outcomes. By contrast, a public health paradigm considers the population impact and encompasses measures of community benefits against a range of outcomes. For example, measurement of the FPHV of vaccination may incorporate health inequity, social and political disruption, disruption of household integrity, school absenteeism and work loss, health care utilization, long-term/on-going disability, the development of antibiotic resistance, and a range of non-etiologically and etiologically defined clinical outcomes. Following an initial conference at the Fondation Mérieux in mid-2015, a second conference (December 2016) was held to further describe the efficacy of using the FPHV of vaccination on a variety of prophylactic vaccines. The wider scope of vaccine benefits, improvement in risk assessment, and the need for partnership and coalition building across interventions has also been discussed during the 2014 and 2016 Global Vaccine and Immunization Research Forums and the 2016 Geneva Health Forum, as well as in numerous publications including a special issue of Health Affairs in February 2016. The December 2016 expert panel concluded that while progress has been made, additional efforts will be necessary to have a more fully formulated assessment of the FPHV of vaccines included into the evidence-base for the value proposition and analysis of unmet medical need to prioritize vaccine development, vaccine licensure, implementation policies and financing decisions. The desired outcomes of these efforts to establish an alternative framework for vaccine evaluation are a more robust vaccine pipeline, improved appreciation of vaccine value and hence of its relative affordability, and greater public access and acceptance of vaccines.

Community effectiveness of indoor spraying as a dengue vector control method: A systematic review

Background

The prevention and control of dengue rely mainly on vector control methods, including indoor residual spraying (IRS) and indoor space spraying (ISS). This study aimed to systematically review the available evidence on community effectiveness of indoor spraying.

Methods

A systematic review was conducted using seven databases (PubMed, EMBASE, LILACS, Web of Science, WHOLIS, Cochrane, and Google Scholar) and a manual search of the reference lists of the identified studies. Data from included studies were extracted, analysed and reported.

Results

The review generated seven studies only, three IRS and four ISS (two/three controlled studies respectively). Two IRS studies measuring human transmission showed a decline. One IRS and all four ISS studies measuring adult mosquitoes showed a very good effect, up to 100%, but not sustained. Two IRS studies and one ISS measuring immature mosquitoes, showed mixed results.

Conclusions

It is evident that IRS and also ISS are effective adulticidal interventions against Aedes mosquitoes. However, evidence to suggest effectiveness of IRS as a larvicidal intervention and to reduce human dengue cases is limited–and even more so for ISS. Overall, there is a paucity of studies available on these two interventions that may be promising for dengue vector control, particularly for IRS with its residual effect.

The effectiveness of indoor residual spraying (IRS) and indoor space spraying (ISS) as dengue vector control methods depends on many factors. This study aims to systematically review the evidence on the community effectiveness of indoor spraying of insecticides to reduce Aedes mosquito populations and thereby to control dengue transmission. A systematic literature review was performed in PubMed, EMBASE, LILACS, Web of Science, WHO library database (WHOLIS), Cochrane, and Google Scholar, including a manual search of the reference lists of the identified studies since its inceptions until 15.02.2017. A total of 39 articles were retrieved for full assessment. Seven studies were included and analysed after final application of inclusion and exclusion criteria: two IRS studies with control, one without, three ISS studies and one, respectively. One IRS study and four ISS studies showed good evidence of effectiveness on adult Aedes mosquitoes. Evidence of effectiveness of IRS as a larvicidal intervention exists but is still inadequate, and is weak for ISS. Evidence of effectiveness of IRS on human dengue cases as a single intervention exists, but was limited and not available for ISS. It is recommended to scale up the research regarding the community effectiveness of IRS and ISS, including measuring dengue transmission, particularly, for IRS with its residual effect. It is also suggested to study in depth the factors that could affect the community effectiveness of IRS and ISS on Aedes populations and on human dengue cases.

Determining the outcomes of interventions to prevent respiratory syncytial virus disease in children: what to measure?

Respiratory syncytial virus (RSV) is the most common cause of viral acute lower respiratory tract illness (LRTI) in young children, and a major cause of hospital admissions and health-care utilisation globally. Substantial efforts have been made to develop RSV vaccines and vaccine-like monoclonal antibodies to prevent acute RSV LRTI. Prevention of acute disease could improve long-term lung health, with potential effects on wheezing, asthma, and chronic lung disease. This Personal View describes assessments that should be initiated during clinical trials and continued after licensure to fully evaluate the effect of RSV preventive interventions. These assessments include recording the incidence of RSV-specific LRTI and all-cause LRTI through two RSV seasons, and assessment of the prevalence and severity of recurrent wheezing or asthma in children aged up to 6 years. Standardised assessments in diverse settings are needed to fully determine the effect of interventions for the prevention of RSV disease.

The public health value of vaccines beyond efficacy: methods, measures and outcomes

BACKGROUND

Assessments of vaccine efficacy and safety capture only the minimum information needed for regulatory approval, rather than the full public health value of vaccines. Vaccine efficacy provides a measure of proportionate disease reduction, is usually limited to etiologically confirmed disease, and focuses on the direct protection of the vaccinated individual. Herein, we propose a broader scope of methods, measures and outcomes to evaluate the effectiveness and public health impact to be considered for evidence-informed policymaking in both pre- and post-licensure stages.

DISCUSSION

Pre-licensure: Regulatory concerns dictate an individually randomised clinical trial. However, some circumstances (such as the West African Ebola epidemic) may require novel designs that could be considered valid for licensure by regulatory agencies. In addition, protocol-defined analytic plans for these studies should include clinical as well as etiologically confirmed endpoints (e.g. all cause hospitalisations, pneumonias, acute gastroenteritis and others as appropriate to the vaccine target), and should include vaccine-preventable disease incidence and 'number needed to vaccinate' as outcomes. Post-licensure: There is a central role for phase IV cluster randomised clinical trials that allows for estimation of population-level vaccine impact, including indirect, total and overall effects. Dynamic models should be prioritised over static models as the constant force of infection assumed in static models will usually underestimate the effectiveness and cost-effectiveness of the immunisation programme by underestimating indirect effects. The economic impact of vaccinations should incorporate health and non-health benefits of vaccination in both the vaccinated and unvaccinated populations, thus allowing for estimation of the net social value of vaccination.

CONCLUSIONS

The full benefits of vaccination reach beyond direct prevention of etiologically confirmed disease and often extend across the life course of a vaccinated person, prevent outcomes in the wider community, stabilise health systems, promote health equity, and benefit local and national economies. The degree to which vaccinations provide broad public health benefits is stronger than for other preventive and curative interventions.

Effectiveness of pneumococcal vaccines in preventing pneumonia in adults, a systematic review and meta-analyses of observational studies

INTRODUCTION

S. pneumoniae can cause a wide spectrum of diseases, including invasive pneumococcal disease and pneumonia. Two types of pneumococcal vaccines are indicated for use in adults: 23-valent pneumococcal polysaccharide vaccines (PPV23) and a 13-valent pneumococcal conjugate vaccine (PCV13).

OBJECTIVE

To systematically review the literature assessing pneumococcal vaccine effectiveness (VE) against community-acquired pneumonia (CAP) in adults among the general population, the immunocompromised and subjects with underlying risk factors in real-world settings.

METHODS

We searched for peer-reviewed observational studies published between 1980 and 2015 in Pubmed, SciELO or LILACS, with pneumococcal VE estimates against CAP, pneumococcal CAP or nonbacteremic pneumococcal CAP. Meta-analyses and meta-regression for VE against CAP requiring hospitalization in the general population was performed.

RESULTS

1159 unique articles were retrieved of which 33 were included. No studies evaluating PCV13 effectiveness were found. Wide ranges in PPV23 effectiveness estimates for any-CAP were observed among adults ≥65 years (-143% to 60%). The meta-analyzed VE estimate for any-CAP requiring hospitalization in the general population was 10.2% (95%CI: -12.6; 33.0). The meta-regression indicates that VE against any-CAP requiring hospitalization is significantly lower in studies with a maximum time since vaccination ≥60 months vs. <60 months and in countries with the pediatric PCV vaccine available on the private market. However, these results should be interpreted cautiously due to the high influence of two studies. The VE estimates for pneumococcal CAP hospitalization ranged from 32% (95%CI: -18; 61) to 51% (95%CI: 16; 71) in the general population.

CONCLUSIONS

Wide ranges in PPV23 effectiveness estimates for any-CAP were observed, likely due to a great diversity of study populations, circulation of S. pneumoniae serotypes, coverage of pediatric pneumococcal vaccination, case definition and time since vaccination. Despite some evidence for short-term protection, effectiveness of PPV23 against CAP was not consistent in the general population, the immunocompromised and subjects with underlying risk factors.

Prevention and control of dengue-the light at the end of the tunnel

Advances in the development of new dengue control tools, including vaccines and vector control, herald a new era of desperately needed dengue prevention and control. The burden of dengue has expanded for decades, and now affects more than 120 countries. Complex, large-scale global forces have and will continue to contribute to the expansion of dengue, including population growth, unplanned urbanisation, and suboptimal mosquito control in urban centres. Although no so-called magic bullets are available, there is new optimism following the first licensure of a dengue vaccine and other promising vaccine candidates, and the development of novel vector control interventions to help control dengue and other expanding mosquito-borne diseases such as Zika virus. Implementation of effective and sustainable immunisation programmes to complement existing methods will add complexity to the health systems of affected countries, which have varying levels of robustness and maturity. Long-term high prioritisation and adequate resources are needed. The way forward is full commitment to addressing a complex disease with a set of solutions integrating vaccination and vector control methods. A whole systems approach is thus needed to integrate these various approaches and strategies for controlling dengue within the goal of universal health coverage. The ultimate objective of these interventions will be to reduce the disease burden in a sustainable and equitable manner.

High pneumonia lifetime-ever incidence in Beijing children compared with locations in other countries, and implications for national PCV and Hib vaccination

OBJECTIVES

To compare the proportion of Beijing children who have ever had pneumonia (%Pneumonia) to those in other locations, and to estimate by how much national vaccine coverage with Pneumococcal Conjugate Vaccine (PCV) and Haemophilus Influenzae Type b (Hib) could reduce Beijing %Pneumonia.

METHODS

%Pneumonia was obtained for each age group from 1 to 8 years inclusive from 5,876 responses to a cross-sectional questionnaire. Literature searches were conducted for world-wide reports of %Pneumonia. Previous vaccine trials conducted worldwide were used to estimate the pneumococcal (S. pneumoniae) and Hib (H. influenzae) burdens and %Pneumonia as well as the potential for PCV and Hib vaccines to reduce Beijing children's %Pneumonia.

FINDINGS

The majority of pneumonia cases occurred by the age of three. The cumulative %Pneumonia for 3-8 year-old Beijing children, 26.9%, was only slightly higher than the 25.4% for the discrete 3 year-old age group, similar to trends for Tianjin (China) and Texas (USA). Beijing's %Pneumonia is disproportionally high relative to its Gross National Income (GNI) per capita, and markedly higher than %Pneumonia in the US and other high GNI per capita countries. Chinese diagnostic guidelines recommend chest X-ray confirmation while most other countries discourage it in favor of clinical diagnosis. Literature review shows that chest X-ray confirmation returns far fewer pneumonia diagnoses than clinical diagnosis. Accordingly, Beijing's %Pneumonia is likely higher than indicated by raw numbers. Vaccine trials suggest that national PCV and Hib vaccination could reduce Beijing's %Pneumonia from 26.9% to 19.7% and 24.9% respectively.

CONCLUSION

National PCV and Hib vaccination programs would substantially reduce Beijing children's pneumonia incidence.