The disease burden of respiratory syncytial virus in older adults.

PURPOSE OF REVIEW: To highlight the respiratory syncytial virus (RSV) disease burden and the current developments and challenges in RSV prevention for older adults ≥60 years through analysis of RSV epidemiology and the effectiveness of emerging vaccines. RECENT FINDINGS: In industrialized countries, RSV incidence rates and hospitalization rates among older adults are estimated to be 600.7 cases per 100 000 person-years and 157 hospitalizations per 100 000 person-years, respectively. Yet, accurately determining RSV morbidity and mortality in older adults is challenging, thus resulting in substantially under-estimating the disease burden. The in-hospital fatality rates vary substantially with age and geographies, and can be as high as 9.1% in developing countries. Two promising RSV vaccines for the elderly have been approved, demonstrating efficacies of up to 94.1%, signifying considerable advancement in RSV prevention. However, concerns over potential side effects remain. SUMMARY: RSV is associated with a significant burden in older adults. While the landscape of RSV prevention in older adults is promising with the licensure of vaccines from two companies, current trial data underscore the need for additional studies. Addressing the real-world effectiveness of these vaccines, understanding potential rare side effects, and ensuring broad inclusivity in future trials are crucial steps to maximize their potential benefits.

Understanding the Potential Drivers for Respiratory Syncytial Virus Rebound During the Coronavirus Disease 2019 Pandemic.

Nonpharmaceutical interventions (NPIs) were widely introduced to combat the coronavirus disease 2019 (COVID-19) pandemic. These interventions also likely led to substantially reduced activity of respiratory syncytial virus (RSV). From late 2020, some countries observed out-of-season RSV epidemics. Here, we analyzed the role of NPIs, population mobility, climate, and severe acute respiratory syndrome coronavirus 2 circulation in RSV rebound through a time-to-event analysis across 18 countries. Full (re)opening of schools was associated with an increased risk for RSV rebound (hazard ratio [HR], 23.29 [95% confidence interval {CI}, 1.09-495.84]); every 5°C increase in temperature was associated with a decreased risk (HR, 0.63 [95% CI, .40-.99]). There was an increasing trend in the risk for RSV rebound over time, highlighting the role of increased population susceptibility. No other factors were found to be statistically significant. Further analysis suggests that increasing population susceptibility and full (re)opening of schools could both override the countereffect of high temperatures, which explains the out-of-season RSV epidemics during the COVID-19 pandemic.

Managing pneumonia through facility-based integrated management of childhood management (IMCI) services: an analysis of the service availability and readiness among public health facilities in Bangladesh.

BACKGROUND: With an estimated 24,000 deaths per year, pneumonia is the single largest cause of death among young children in Bangladesh, accounting for 18% of all under-5 deaths. The Government of Bangladesh adopted the WHO recommended Integrated Management of Childhood Illness (IMCI)-strategy in 1998 for outpatient management of pneumonia, which was scaled-up nationally by 2014. This paper reports the service availability and readiness related to IMCI-based pneumonia management in Bangladesh. We conducted a secondary analysis of the Bangladesh Health Facility Survey-2017, which was conducted with a nationally representative sample including all administrative divisions and types of health facilities. We limited our analysis to District Hospitals (DHs), Maternal and Child Welfare Centres (MCWCs), Upazila (sub-district) Health Complexes (UHCs), and Union Health and Family Welfare Centres (UH&FWCs), which are mandated to provide IMCI services. Readiness was reported based on 10 items identified by national experts as 'essential' for pneumonia management. RESULTS: More than 90% of DHs and UHCs, and three-fourths of UH&FWCs and MCWCs provide IMCI-based pneumonia management services. Less than two-third of the staff had ever received IMCI-based pneumonia training. Only one-third of the facilities had a functional ARI timer or a watch able to record seconds on the day of the visit. Pulse oximetry was available in 27% of the district hospitals, 18% of the UHCs and none of the UH&FWCs. Although more than 80% of the facilities had amoxicillin syrup or dispersible tablets, only 16% had injectable gentamicin. IMCI service registers were not available in nearly one-third of the facilities and monthly reporting forms were not available in around 10% of the facilities. Only 18% of facilities had a high-readiness (score 8-10), whereas 20% had a low-readiness (score 0-4). The readiness was significantly poorer among rural and lower level facilities (p < 0.001). Seventy-two percent of the UHCs had availability of one of any of the four oxygen sources (oxygen concentrators, filled oxygen cylinder with flowmeter, filled oxygen cylinder without flowmeter, and oxygen distribution system) followed by DHs (66%) and MCWCs (59%). CONCLUSION: There are substantial gaps in the readiness related to IMCI-based pneumonia management in public health facilities in Bangladesh. Since pneumonia remains a major cause of child death nationally, Bangladesh should make a substantial effort in programme planning, implementation and monitoring to address these critical gaps to ensure better provision of essential care for children suffering from pneumonia.

Cost of hospital management of Clostridium difficile infection in United States-a meta-analysis and modelling study.

BACKGROUND: Clostridium difficile infection (CDI) is the leading cause of infectious nosocomial diarrhoea but the economic costs of CDI on healthcare systems in the US remain uncertain. METHODS: We conducted a systematic search for published studies investigating the direct medical cost associated with CDI hospital management in the past 10 years (2005-2015) and included 42 studies to the final data analysis to estimate the financial impact of CDI in the US. We also conducted a meta-analysis of all costs using Monte Carlo simulation. RESULTS: The average cost for CDI case management and average CDI-attributable costs per case were $42,316 (90 % CI: $39,886, $44,765) and $21,448 (90 % CI: $21,152, $21,744) in 2015 US dollars. Hospital-onset CDI-attributable cost per case was $34,157 (90 % CI: $33,134, $35,180), which was 1.5 times the cost of community-onset CDI ($20,095 [90 % CI: $4991, $35,204]). The average and incremental length of stay (LOS) for CDI inpatient treatment were 11.1 (90 % CI: 8.7-13.6) and 9.7 (90 % CI: 9.6-9.8) days respectively. Total annual CDI-attributable cost in the US is estimated US$6.3 (Range: $1.9-$7.0) billion. Total annual CDI hospital management required nearly 2.4 million days of inpatient stay. CONCLUSIONS: This review indicates that CDI places a significant financial burden on the US healthcare system. This review adds strong evidence to aid policy-making on adequate resource allocation to CDI prevention and treatment in the US. Future studies should focus on recurrent CDI, CDI in long-term care facilities and persons with comorbidities and indirect cost from a societal perspective. Health-economic studies for CDI preventive intervention are needed.

Effectiveness of seasonal influenza vaccines in children -- a systematic review and meta-analysis.

AIM: To assess the efficacy and effectiveness of seasonal influenza vaccines in healthy children up to the age of 18 years. METHODS: MedLine, EMBASE, CENTRAL, CINAHL, WHOLIS, LILACS, and Global Health were searched for randomized controlled trials and cohort and case-control studies investigating the efficacy or effectiveness of influenza vaccines in healthy children up to the age of 18 years. The studies were assessed for their quality and data on the outcomes of influenza-like illness, laboratory-confirmed influenza, and hospitalizations were extracted. Seven meta-analyses were performed for different vaccines and different study outcomes. RESULTS: Vaccine efficacy for live vaccines, using random effects model, was as follows: (i) for similar antigen, using per-protocol analysis: 83.4% (78.3%-88.8%); (ii) for similar antigen, using intention to treat analysis: 82.5 (76.7%-88.6%); (iii) for any antigen, using per protocol analysis: 76.4% (68.7%-85.0%); (iv) for any antigen, using intention to treat analysis: 76.7% (68.8%-85.6%). Vaccine efficacy for inactivated vaccines, for similar antigen, using random effects model, was 67.3% (58.2%-77.9%). Vaccine effectiveness against influenza-like illness for live vaccines, using random effects model, was 31.4% (24.8%-39.6%) and using fixed-effect model 44.3% (42.6%-45.9%). Vaccine effectiveness against influenza-like illness for inactivated vaccines, using random effects model, was 32.5% (20.0%-52.9%) and using fixed-effect model 42.6% (38.3%-47.5%). CONCLUSIONS: Influenza vaccines showed high efficacy in children, particularly live vaccines. Effectiveness was lower and the data on hospitalizations were very limited.

Report of the WHO technical consultation on the evaluation of respiratory syncytial virus prevention cost effectiveness in low- and middle-income countries, April 7-8, 2022.

Policymakers often rely on impact and cost-effectiveness evaluations to inform decisions about the introduction of health interventions in low- and middle-income countries (LMICs); however, cost-effectiveness results for the same health intervention can differ by the choice of parameter inputs, modelling assumptions, and geography. Anticipating the near-term availability of new respiratory syncytial virus (RSV) prevention products, WHO convened a two-day virtual consultation in April 2022 with stakeholder groups and global experts in health economics, epidemiology, and vaccine implementation. The objective was to review methods, parameterization, and results of existing cost-effectiveness analyses for RSV prevention in LMICs; identify the most influential inputs and data limitations; and recommend and prioritize future data gathering and research to improve RSV prevention impact estimates in LMICs. Epidemiological parameters identified as both influential and uncertain were those associated with RSV hospitalization and death, specifically setting-specific hospitalization rates and RSV-attributable death rates. Influential economic parameters included product price, delivery costs, willingness-to-pay for health on the part of potential donors, and the cost of RSV-associated hospitalization. Some of the influential parameters identified at this meeting should be more precisely measured by further research. Other influential economic parameters that are highly uncertain may not be resolved, and it is appropriate to use sensitivity analyses to explore these within cost-effectiveness evaluations. This report highlights the presentations and major discussions of the meeting.

An evaluation of oxygen systems for treatment of childhood pneumonia.

BACKGROUND: Oxygen therapy is recommended for all of the 1.5 - 2.7 million young children who consult health services with hypoxemic pneumonia each year, and the many more with other serious conditions. However, oxygen supplies are intermittent throughout the developing world. Although oxygen is well established as a treatment for hypoxemic pneumonia, quantitative evidence for its effect is lacking. This review aims to assess the utility of oxygen systems as a method for reducing childhood mortality from pneumonia. METHODS: Aiming to improve priority setting methods, The Child Health and Nutrition Research Initiative (CHNRI) has developed a common framework to score competing interventions into child health. That framework involves the assessment of 12 different criteria upon which interventions can be compared. This report follows the proposed framework, using a semi-systematic literature review and the results of a structured exercise gathering opinion from experts (leading basic scientists, international public health researchers, international policy makers and representatives of pharmaceutical companies), to assess and score each criterion as their "collective optimism" towards each, on a scale from 0 to 100%. RESULTS: A rough estimate from an analysis of the literature suggests that global strengthening of oxygen systems could save lives of up to 122,000 children from pneumonia annually. Following 12 CHNRI criteria, the experts expressed very high levels of optimism (over 80%) for answerability, low development cost and low product cost; high levels of optimism (60-80%) for low implementation cost, likelihood of efficacy, deliverability, acceptance to end users and health workers; and moderate levels of optimism (40-60%) for impact on equity, affordability and sustainability. The median estimate of potential effectiveness of oxygen systems to reduce the overall childhood pneumonia mortality was ~20% (interquartile range: 10-35%, min. 0%, max. 50%). However, problems with oxygen systems in terms of affordability, sustainability and impact on equity are noted in both expert opinion scores and on review. CONCLUSION: Oxygen systems are likely to be an effective intervention in combating childhood mortality from pneumonia. However, a number of gaps in the evidence base exist that should be addressed to complete the investment case and research addressing these issues merit greater funding attention.

An evaluation of respiratory administration of measles vaccine for prevention of acute lower respiratory infections in children.

BACKGROUND: Measles was responsible for an estimated 100,000 deaths worldwide in 2008. Despite being a vaccine-preventable disease, measles remains a major cause of morbidity and mortality in young children. Although a safe and effective injectable measles vaccine has been available for over 50 years it has not been possible to achieve the uniformly high levels of coverage (required to achieve measles eradication) in most parts of the developing world. Aerosolised measles vaccines are now under development with the hope of challenging the delivery factors currently limiting the coverage of the existing vaccine. METHODS: We used a modified CHNRI methodology for setting priorities in health research investments to assess the strengths and weaknesses of this emerging intervention to decrease the burden of childhood pneumonia. This was done in two stages. In Stage I, we systematically reviewed the literature related to emerging aerosol vaccines against measles relevant to several criteria of interest. Although there are a number of different aerosol vaccine approaches under development, for the purpose of this exercise, all were considered as one intervention. The criteria of interest were: answerability; cost of development, production and implementation; efficacy and effectiveness; deliverability, affordability and sustainability; maximum potential impact on disease burden reduction; acceptability to the end users and health workers; and effect on equity. In Stage II, we conducted an expert opinion exercise by inviting 20 experts (leading basic scientists, international public health researchers, international policy makers and representatives of pharmaceutical companies). The policy makers and industry representatives accepted our invitation on the condition of anonymity, due to the sensitive nature of their involvement in such exercises. They answered questions from the CHNRI framework and their "collective optimism" towards each criterion was documented on a scale from 0 to 100%. RESULTS: The panel of experts expressed mixed feelings about an aerosol measles vaccine. The group expressed low levels of optimism regarding the criteria of likelihood of efficacy and low cost of development (scores around 50%); moderate levels of optimism regarding answerability, low cost of production, low cost of implementation and affordability (score around 60%); and high levels of optimism regarding deliverability, impact on equity and acceptability to health workers and end-users (scores over 80%). Finally, the experts felt that this intervention will have a modest but nevertheless important impact on reduction of burden of disease due to childhood pneumonia (median: 5%, interquartile range 1-15%, minimum 0%, maximum 45%). CONCLUSION: Aerosol measles vaccine is at an advanced stage of development, with evidence of good immunogenicity. This new intervention will be presented as a feasible candidate strategy in the campaign for global elimination of measles. It also presents an unique opportunity to decrease the overall burden of disease due to severe pneumonia in young children.

An evaluation of emerging vaccines for childhood meningococcal disease.

BACKGROUND: Meningococcal meningitis is a major cause of disease worldwide, with frequent epidemics particularly affecting an area of sub-Saharan Africa known as the "meningitis belt". Neisseria meningitidis group A (MenA) is responsible for major epidemics in Africa. Recently W-135 has emerged as an important pathogen. Currently, the strategy for control of such outbreaks is emergency use of meningococcal (MC) polysaccharide vaccines, but these have a limited ability to induce herd immunity and elicit an adequate immune response in infant and young children. In recent times initiatives have been taken to introduce meningococcal conjugate vaccine in these African countries. Currently there are two different types of MC conjugate vaccines at late stages of development covering serogroup A and W-135: a multivalent MC conjugate vaccine against serogroup A,C,Y and W-135; and a monovalent conjugate vaccine against serogroup A. We aimed to perform a structured assessment of these emerging meningococcal vaccines as a means of reducing global meningococcal disease burden among children under 5 years of age. METHODS: We used a modified CHNRI methodology for setting priorities in health research investments. This was done in two stages. In the first stage we systematically reviewed the literature related to emerging MC vaccines relevant to 12 criteria of interest. In Stage II, we conducted an expert opinion exercise by inviting 20 experts (leading basic scientists, international public health researchers, international policy makers and representatives of pharmaceutical companies). They answered questions from CHNRI framework and their "collective optimism" towards each criterion was documented on a scale from 0 to 100%. RESULTS: For MenA conjugate vaccine the experts showed very high level of optimism (~ 90% or more) for 7 out of the 12 criteria. The experts felt that the likelihood of efficacy on meningitis was very high (~ 90%). Deliverability, acceptability to health workers, end users and the effect on equity were all seen as highly likely (~ 90%). In terms of the maximum potential impact on meningitis disease burden, the median potential effectiveness of the vaccines in reduction of overall meningitis mortality was estimated to be 20%; (interquartile range 20-40% and min. 8%, max 50 %). For the multivalent meningococcal vaccines the experts had similar optimism for most of the 12 CHNRI criteria with slightly lower optimism in answerability and low development cost criteria. The main concern was expressed over the cost of product, its affordability and cost of implementation. CONCLUSIONS: With increasing recognition of the burden of meningococcal meningitis, especially during epidemics in Africa, it is vitally important that strategies are taken to reduce the morbidity and mortality attributable to this disease. Improved MC vaccines are a promising investment that could substantially contribute to reduction of child meningitis mortality world-wide.

An evaluation of emerging vaccines for childhood pneumococcal pneumonia.

BACKGROUND: Pneumonia is the leading cause of child mortality worldwide. Streptococcus pneumoniae (SP) or pneumococcus is estimated to cause 821,000 child deaths each year. It has over 90 serotypes, of which 7 to 13 serotypes are included in current formulations of pneumococcal conjugate vaccines that are efficacious in young children. To further reduce the burden from SP pneumonia, a vaccine is required that could protect children from a greater diversity of serotypes. Two different types of vaccines against pneumococcal pneumonia are currently at varying stages of development: a multivalent pneumococcal conjugate vaccine covering additional SP serotypes; and a conserved common pneumococcal protein antigen (PPA) vaccine offering protection for all serotypes. METHODS: We used a modified CHNRI methodology for setting priorities in health research investments. This was done in two stages. In Stage I, we systematically reviewed the literature related to emerging SP vaccines relevant to several criteria of interest: answerability; efficacy and effectiveness; cost of development, production and implementation; deliverability, affordability and sustainability; maximum potential for disease burden reduction; acceptability to the end users and health workers; and effect on equity. In Stage II, we conducted an expert opinion exercise by inviting 20 experts (leading basic scientists, international public health researchers, international policy makers and representatives of pharmaceutical companies). The policy makers and industry representatives accepted our invitation on the condition of anonymity, due to sensitive nature of their involvement in such exercises. They answered questions from CHNRI framework and their "collective optimism" towards each criterion was documented on a scale from 0 to 100%. RESULTS: The experts expressed very high level of optimism (over 80%) that low-cost polysaccharide conjugate SP vaccines would satisfy each of the 9 relevant CHNRI criteria. The median potential effectiveness of conjugate SP vaccines in reduction of overall childhood pneumonia mortality was predicted to be about 25% (interquartile range 20-38%, min. 15%, max 45%). For low cost, cross-protective common protein vaccines for SP the experts expressed concerns over answerability (72%) and the level of development costs (50%), while the scores for all other criteria were over 80%. The median potential effectiveness of common protein vaccines in reduction of overall childhood pneumonia mortality was predicted to be about 30% (interquartile range 26-40%, min. 20%, max 45%). CONCLUSIONS: Improved SP vaccines are a very promising investment that could substantially contribute to reduction of child mortality world-wide.

Influenza vaccination strategies for 2020-21 in the context of COVID-19.

BACKGROUND: Influenza vaccination prevents people from influenza-related diseases and thereby mitigates the burden on national health systems when COVID-19 circulates and public health measures controlling respiratory viral infections are relaxed. However, it is challenging to maintain influenza vaccine services as the COVID-19 pandemic has the potential to disrupt vaccination programmes in many countries during the 2020/21 winter. We summarise available recommendations and strategies on influenza vaccination, specifically the changes in the context of the COVID-19 pandemic. METHODS: We searched websites and databases of national and international public health agencies (focusing on Europe, North and South America, Australia, New Zealand, and South Africa). We also contacted key influenza immunization focal points and experts in respective countries and organizations including WHO and ECDC. RESULTS: Available global and regional guidance emphasises the control of COVID-19 infection in immunisation settings by implementing multiple measures, such as physical distancing, hand hygiene practice, appropriate use of personal protective equipment by health care workers and establishing separate vaccination sessions for medically vulnerable people. The guidance also emphasises using alternative models or settings (eg, outdoor areas and pharmacies) for vaccine delivery, communication strategies and developing registry and catch-up programmes to achieve high coverage. Several novel national strategies have been adopted, such as combining influenza vaccination with other medical visits and setting up outdoor and drive through vaccination clinics. Several Southern Hemisphere countries have increased influenza vaccine coverage substantially for the 2020 influenza season. Most of the countries included in our review have planned a universal or near universal influenza vaccination for health care workers, or have made influenza vaccination for health care workers mandatory. Australia has requested that all workers and visitors in long term care facilities receive influenza vaccine. The UK has planned to expand the influenza programme to provide free influenza vaccine for the first time to all adults 50-64 years of age, people on the shielded patient list and their household members and children in the first year of secondary school. South Africa has additionally prioritised people with hypertension for influenza vaccination. CONCLUSIONS: This review of influenza vaccination guidance and strategies should support strategy development on influenza vaccination in the context of COVID-19.

The respiratory syncytial virus vaccine landscape: lessons from the graveyard and promising candidates.

The global burden of disease caused by respiratory syncytial virus (RSV) is increasingly recognised, not only in infants, but also in older adults (aged ≥65 years). Advances in knowledge of the structural biology of the RSV surface fusion glycoprotein have revolutionised RSV vaccine development by providing a new target for preventive interventions. The RSV vaccine landscape has rapidly expanded to include 19 vaccine candidates and monoclonal antibodies (mAbs) in clinical trials, reflecting the urgency of reducing this global health problem and hence the prioritisation of RSV vaccine development. The candidates include mAbs and vaccines using four approaches: (1) particle-based, (2) live-attenuated or chimeric, (3) subunit, (4) vector-based. Late-phase RSV vaccine trial failures highlight gaps in knowledge regarding immunological protection and provide lessons for future development. In this Review, we highlight promising new approaches for RSV vaccine design and provide a comprehensive overview of RSV vaccine candidates and mAbs in clinical development to prevent one of the most common and severe infectious diseases in young children and older adults worldwide.

Serotype distribution of Streptococcus pneumoniae causing invasive disease in children in the post-PCV era: A systematic review and meta-analysis.

BACKGROUND: Routine immunisation with pneumococcal conjugate vaccines (PCV7/10/13) has reduced invasive pneumococcal disease (IPD) due to vaccine serotypes significantly. However, an increase in disease due to non-vaccine types, or serotype replacement, has been observed. Serotypes' individual contributions to IPD play a critical role in determining the overall effects of PCVs. This study examines the distribution of pneumococcal serotypes in children to identify leading serotypes associated with IPD post-PCV introduction. METHODS: A systematic search was performed to identify studies and surveillance reports (published between 2000 and December 2015) of pneumococcal serotypes causing childhood IPD post-PCV introduction. Serotype data were differentiated based on the PCV administered during the study period: PCV7 or higher valent PCVs (PCV10 or PCV13). Meta-analysis was conducted to estimate the proportional contributions of the most frequent serotypes in childhood IPD in each period. RESULTS: We identified 68 studies reporting serotype data among IPD cases in children. We analysed data from 38 studies (14 countries) where PCV7 was administered and 20 (24 countries) where PCV10 or PCV13 have been introduced. Studies reported early and late periods of PCV7 administration (range: 2001∓13). In these settings, serotype 19A was the most predominant cause of childhood IPD, accounting for 21.8% (95%CI 18.6∓25.6) of cases. In countries that have introduced higher valent PCVs, study periods were largely representative of the transition and early years of PCV10 or PCV13. In these studies, the overall serotype-specific contribution of 19A was lower (14.2% 95%CI 11.1∓18.3). Overall, non-PCV13 serotypes contributed to 42.2% (95%CI 36.1∓49.5%) of childhood IPD cases. However, regional differences were noted (57.8% in North America, 71.9% in Europe, 45.9% in Western Pacific, 28.5% in Latin America, 42.7% in one African country, and 9.2% in one Eastern Mediterranean country). Predominant non-PCV13 serotypes overall were 22F, 12F, 33F, 24F, 15C, 15B, 23B, 10A, and 38 (descending order), but their rank order varied by region. CONCLUSION: Childhood IPD is associated with a wide number of serotypes. In the early years after introduction of higher valent PCVs, non-PCV13 types caused a considerable proportion of childhood IPD. Serotype data, particularly from resource-limited countries with high burden of IPD, are needed to assess the importance of serotypes in different settings. The geographic diversity of pneumococcal serotypes highlights the importance of continued surveillance to guide vaccine design and recommendations.

Reducing the burden of maternal and neonatal infections in low income settings.

Maternal and neonatal infections remain responsible for up to 1 million deaths each year globally. Current approaches to prevention, early diagnosis and appropriate management are limited by difficulties in developing vaccines against the main pathogens, or alternatively diagnosing the infections accurately and managing them appropriately and effectively in low-resource settings. We propose that short-term priorities should focus on promotion of evidence-based, cost-effective home care practices to prevent maternal and newborn infections, with increased coverage and improved quality of maternal and neonatal care interventions. Longer-term strategic priorities will ultimately need to focus on the development of vaccines and point-of-care diagnostic tests. Diagnostic tests should help establish the aetiological diagnosis and inform treatment decisions. They will also need to be deliverable, affordable, sustainable and acceptable in low-resource settings. The cost-effectiveness of maternal immunization in the protection of neonates will also need to be established.