Expanding antibiotic, vaccine, and diagnostics development and access to tackle antimicrobial resistance.

The increasing number of bacterial infections globally that do not respond to any available antibiotics indicates a need to invest in-and ensure access to-new antibiotics, vaccines, and diagnostics. The traditional model of drug development, which depends on substantial revenues to motivate investment, is no longer economically viable without push and pull incentives. Moreover, drugs developed through these mechanisms are unlikely to be affordable for all patients in need, particularly in low-income and middle-income countries. New, publicly funded models based on public-private partnerships could support investment in antibiotics and novel alternatives, and lower patients' out-of-pocket costs, making drugs more accessible. Cost reductions can be achieved with public goods, such as clinical trial networks and platform-based quality assurance, manufacturing, and product development support. Preserving antibiotic effectiveness relies on accurate and timely diagnosis; however scaling up diagnostics faces technological, economic, and behavioural challenges. New technologies appeared during the COVID-19 pandemic, but there is a need for a deeper understanding of market, physician, and consumer behaviour to improve the use of diagnostics in patient management. Ensuring sustainable access to antibiotics also requires infection prevention. Vaccines offer the potential to prevent infections from drug-resistant pathogens, but funding for vaccine development has been scarce in this context. The High-Level Meeting of the UN General Assembly in 2024 offers an opportunity to rethink how research and development can be reoriented to serve disease management, prevention, patient access, and antibiotic stewardship.

Vaccine value profile for Klebsiella pneumoniae.

Klebsiella pneumoniae causes community- and healthcare-associated infections in children and adults. Globally in 2019, an estimated 1.27 million (95% Uncertainty Interval [UI]: 0.91-1.71) and 4.95 million (95% UI: 3.62-6.57) deaths were attributed to and associated with bacterial antimicrobial resistance (AMR), respectively. K. pneumoniae was the second leading pathogen in deaths attributed to AMR resistant bacteria. Furthermore, the rise of antimicrobial resistance in both community- and hospital-acquired infections is a concern for neonates and infants who are at high risk for invasive bacterial disease. There is a limited antibiotic pipeline for new antibiotics to treat multidrug resistant infections, and vaccines targeted against K. pneumoniae are considered to be of priority by the World Health Organization. Vaccination of pregnant women against K. pneumoniae could reduce the risk of invasive K.pneumoniae disease in their young offspring. In addition, vulnerable children, adolescents and adult populations at risk of K. pneumoniae disease with underlying diseases such as immunosuppression from underlying hematologic malignancy, chemotherapy, patients undergoing abdominal and/or urinary surgical procedures, or prolonged intensive care management are also potential target groups for a K. pneumoniae vaccine. A 'Vaccine Value Profile' (VVP) for K.pneumoniae, which contemplates vaccination of pregnant women to protect their babies from birth through to at least three months of age and other high-risk populations, provides a high-level, holistic assessment of the available information to inform the potential public health, economic and societal value of a pipeline of K. pneumoniae vaccines and other preventatives and therapeutics. This VVP was developed by a working group of subject matter experts from academia, non-profit organizations, public-private partnerships, and multi-lateral organizations, and in collaboration with stakeholders from the WHO. All contributors have extensive expertise on various elements of the K.pneumoniae VVP and collectively aimed to identify current research and knowledge gaps. The VVP was developed using only existing and publicly available information.

Genomics for antimicrobial resistance surveillance to support infection prevention and control in health-care facilities.

Integration of genomic technologies into routine antimicrobial resistance (AMR) surveillance in health-care facilities has the potential to generate rapid, actionable information for patient management and inform infection prevention and control measures in near real time. However, substantial challenges limit the implementation of genomics for AMR surveillance in clinical settings. Through a workshop series and online consultation, international experts from across the AMR and pathogen genomics fields convened to review the evidence base underpinning the use of genomics for AMR surveillance in a range of settings. Here, we summarise the identified challenges and potential benefits of genomic AMR surveillance in health-care settings, and outline the recommendations of the working group to realise this potential. These recommendations include the definition of viable and cost-effective use cases for genomic AMR surveillance, strengthening training competencies (particularly in bioinformatics), and building capacity at local, national, and regional levels using hub and spoke models.

Evidence review and recommendations for the implementation of genomics for antimicrobial resistance surveillance: reports from an international expert group.

Nearly a century after the beginning of the antibiotic era, which has been associated with unparalleled improvements in human health and reductions in mortality associated with infection, the dwindling pipeline for new antibiotic classes coupled with the inevitable spread of antimicrobial resistance (AMR) poses a major global challenge. Historically, surveillance of bacteria with AMR typically relied on phenotypic analysis of isolates taken from infected individuals, which provides only a low-resolution view of the epidemiology behind an individual infection or wider outbreak. Recent years have seen increasing adoption of powerful new genomic technologies with the potential to revolutionise AMR surveillance by providing a high-resolution picture of the AMR profile of the bacteria causing infections and providing real-time actionable information for treating and preventing infection. However, many barriers remain to be overcome before genomic technologies can be adopted as a standard part of routine AMR surveillance around the world. Accordingly, the Surveillance and Epidemiology of Drug-resistant Infections Consortium convened an expert working group to assess the benefits and challenges of using genomics for AMR surveillance. In this Series, we detail these discussions and provide recommendations from the working group that can help to realise the massive potential benefits for genomics in surveillance of AMR.

The full value of immunisation against respiratory syncytial virus for infants younger than 1 year: effects beyond prevention of acute respiratory illness.

Respiratory syncytial virus (RSV) is a leading cause of severe respiratory illness and death among children worldwide, particularly in children younger than 6 months and in low-income and middle-income countries. Feasible and cost-effective interventions to prevent RSV disease are not yet widely available, although two new products aimed at preventing RSV disease-long-acting monoclonal antibodies and maternal vaccines-have been licensed within the past 2 years. The primary target of these products is reduction of the substantial burden of RSV-associated acute lower respiratory tract infections (LRTI) in infants younger than 1 year. However, other important public health benefits might also accrue with the prevention of RSV-associated LRTI during the first year of life. Mounting evidence shows that preventing RSV-associated LRTI in infants younger than 1 year could prevent secondary pneumonia caused by other pathogens, reduce recurrent hospitalisations due to other respiratory diseases in later childhood, decrease all-cause infant mortality, ameliorate the burden of respiratory diseases on health-care systems, reduce inappropriate antibiotic use, and possibly improve lung health beyond infancy. We herein review current evidence and suggest approaches to better assess the magnitude of these potential secondary effects of RSV prevention, which, if proven substantial, are likely to be relevant to policy makers in many countries as they consider the use of these new products.

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.

Value profile for respiratory syncytial virus vaccines and monoclonal antibodies.

Respiratory syncytial virus (RSV) is the predominant cause of acute lower respiratory infection (ALRI) in young children worldwide, yet no licensed RSV vaccine exists to help prevent the millions of illnesses and hospitalizations and tens of thousands of young lives taken each year. Monoclonal antibody (mAb) prophylaxis exists for prevention of RSV in a small subset of very high-risk infants and young children, but the only currently licensed product is impractical, requiring multiple doses and expensive for the low-income settings where the RSV disease burden is greatest. A robust candidate pipeline exists to one day prevent RSV disease in infant and pediatric populations, and it focuses on two promising passive immunization approaches appropriate for low-income contexts: maternal RSV vaccines and long-acting infant mAbs. Licensure of one or more candidates is feasible over the next one to three years and, depending on final product characteristics, current economic models suggest both approaches are likely to be cost-effective. Strong coordination between maternal and child health programs and the Expanded Program on Immunization will be needed for effective, efficient, and equitable delivery of either intervention. This 'Vaccine Value Profile' (VVP) for RSV is intended to provide a high-level, holistic assessment of the information and data that are currently available to inform the potential public health, economic and societal value of pipeline vaccines and vaccine-like products. This VVP was developed by a working group of subject matter experts from academia, non-profit organizations, public private partnerships and multi-lateral organizations, and in collaboration with stakeholders from the WHO headquarters. All contributors have extensive expertise on various elements of the RSV VVP and collectively aimed to identify current research and knowledge gaps. The VVP was developed using only existing and publicly available information.

New respiratory syncytial virus immunization products in low- and middle-income countries: potential for cost-effective impact on a high burden of disease in young infants.

As new, efficacious respiratory syncytial virus (RSV) immunization products reach the market, affordable pricing as well as improved estimation of disease burden and the full potential and cost effectiveness of RSV prevention in the hardest hit geographies in low- and middle-income countries are critical to inform country adoption and enable maximum impact against infant disease and mortality globally. The data reported in the special issue underscore the enormous burden, and associated cost, of RSV disease in young infants in several LMICs, including Kenya and South Africa, as well as the potential for RSV maternal vaccines or long-acting monoclonal antibodies, to be cost-effective and possibly even cost-saving.

Global, regional, and national estimates of the impact of a maternal Klebsiella pneumoniae vaccine: A Bayesian modeling analysis.

BACKGROUND: Despite significant global progress in reducing neonatal mortality, bacterial sepsis remains a major cause of neonatal deaths. Klebsiella pneumoniae (K. pneumoniae) is the leading pathogen globally underlying cases of neonatal sepsis and is frequently resistant to antibiotic treatment regimens recommended by the World Health Organization (WHO), including first-line therapy with ampicillin and gentamicin, second-line therapy with amikacin and ceftazidime, and meropenem. Maternal vaccination to prevent neonatal infection could reduce the burden of K. pneumoniae neonatal sepsis in low- and middle-income countries (LMICs), but the potential impact of vaccination remains poorly quantified. We estimated the potential impact of such vaccination on cases and deaths of K. pneumoniae neonatal sepsis and project the global effects of routine immunization of pregnant women with the K. pneumoniae vaccine as antimicrobial resistance (AMR) increases. METHODS AND FINDINGS: We developed a Bayesian mixture-modeling framework to estimate the effects of a hypothetical K. pneumoniae maternal vaccine with 70% efficacy administered with coverage equivalent to that of the maternal tetanus vaccine on neonatal sepsis infections and mortality. To parameterize our model, we used data from 3 global studies of neonatal sepsis and/or mortality-with 2,330 neonates who died with sepsis surveilled from 2016 to 2020 undertaken in 18 mainly LMICs across all WHO regions (Ethiopia, Kenya, Mali, Mozambique, Nigeria, Rwanda, Sierra Leone, South Africa, Uganda, Brazil, Italy, Greece, Pakistan, Bangladesh, India, Thailand, China, and Vietnam). Within these studies, 26.95% of fatal neonatal sepsis cases were culture-positive for K. pneumoniae. We analyzed 9,070 K. pneumoniae genomes from human isolates gathered globally from 2001 to 2020 to quantify the temporal rate of acquisition of AMR genes in K. pneumoniae isolates to predict the future number of drug-resistant cases and deaths that could be averted by vaccination. Resistance rates to carbapenems are increasing most rapidly and 22.43% [95th percentile Bayesian credible interval (CrI): 5.24 to 41.42] of neonatal sepsis deaths are caused by meropenem-resistant K. pneumoniae. Globally, we estimate that maternal vaccination could avert 80,258 [CrI: 18,084 to 189,040] neonatal deaths and 399,015 [CrI: 334,523 to 485,442] neonatal sepsis cases yearly worldwide, accounting for more than 3.40% [CrI: 0.75 to 8.01] of all neonatal deaths. The largest relative benefits are in Africa (Sierra Leone, Mali, Niger) and South-East Asia (Bangladesh) where vaccination could avert over 6% of all neonatal deaths. Nevertheless, our modeling only considers country-level trends in K. pneumoniae neonatal sepsis deaths and is unable to consider within-country variability in bacterial prevalence that may impact the projected burden of sepsis. CONCLUSIONS: A K. pneumoniae maternal vaccine could have widespread, sustained global benefits as AMR in K. pneumoniae continues to increase.

Respiratory syncytial virus prevention within reach: the vaccine and monoclonal antibody landscape.

Respiratory syncytial virus is the second most common cause of infant mortality and a major cause of morbidity and mortality in older adults (aged >60 years). Efforts to develop a respiratory syncytial virus vaccine or immunoprophylaxis remain highly active. 33 respiratory syncytial virus prevention candidates are in clinical development using six different approaches: recombinant vector, subunit, particle-based, live attenuated, chimeric, and nucleic acid vaccines; and monoclonal antibodies. Nine candidates are in phase 3 clinical trials. Understanding the epitopes targeted by highly neutralising antibodies has resulted in a shift from empirical to rational and structure-based vaccine and monoclonal antibody design. An extended half-life monoclonal antibody for all infants is likely to be within 1 year of regulatory approval (from August, 2022) for high-income countries. Live-attenuated vaccines are in development for older infants (aged >6 months). Subunit vaccines are in late-stage trials for pregnant women to protect infants, whereas vector, subunit, and nucleic acid approaches are being developed for older adults. Urgent next steps include ensuring access and affordability of a respiratory syncytial virus vaccine globally. This review gives an overview of respiratory syncytial virus vaccines and monoclonal antibodies in clinical development highlighting different target populations, antigens, and trial results.

Health-care-associated bloodstream and urinary tract infections in a network of hospitals in India: a multicentre, hospital-based, prospective surveillance study.

BACKGROUND: Health-care-associated infections (HAIs) cause significant morbidity and mortality globally, including in low-income and middle-income countries (LMICs). Networks of hospitals implementing standardised HAI surveillance can provide valuable data on HAI burden, and identify and monitor HAI prevention gaps. Hospitals in many LMICs use HAI case definitions developed for higher-resourced settings, which require human resources and laboratory and imaging tests that are often not available. METHODS: A network of 26 tertiary-level hospitals in India was created to implement HAI surveillance and prevention activities. Existing HAI case definitions were modified to facilitate standardised, resource-appropriate surveillance across hospitals. Hospitals identified health-care-associated bloodstream infections and urinary tract infections (UTIs) and reported clinical and microbiological data to the network for analysis. FINDINGS: 26 network hospitals reported 2622 health-care-associated bloodstream infections and 737 health-care-associated UTIs from 89 intensive care units (ICUs) between May 1, 2017, and Oct 31, 2018. Central line-associated bloodstream infection rates were highest in neonatal ICUs (>20 per 1000 central line days). Catheter-associated UTI rates were highest in paediatric medical ICUs (4·5 per 1000 urinary catheter days). Klebsiella spp (24·8%) were the most frequent organism in bloodstream infections and Candida spp (29·4%) in UTIs. Carbapenem resistance was common in Gram-negative infections, occurring in 72% of bloodstream infections and 76% of UTIs caused by Klebsiella spp, 77% of bloodstream infections and 76% of UTIs caused by Acinetobacter spp, and 64% of bloodstream infections and 72% of UTIs caused by Pseudomonas spp. INTERPRETATION: The first standardised HAI surveillance network in India has succeeded in implementing locally adapted and context-appropriate protocols consistently across hospitals and has been able to identify a large number of HAIs. Network data show high HAI and antimicrobial resistance rates in tertiary hospitals, showing the importance of implementing multimodal HAI prevention and antimicrobial resistance containment strategies. FUNDING: US Centers for Disease Control and Prevention cooperative agreement with All India Institute of Medical Sciences, New Delhi. TRANSLATION: For the Hindi translation of the abstract see Supplementary Materials section.

An algorithmic approach to identifying the aetiology of acute encephalitis syndrome in India: results of a 4-year enhanced surveillance study.

BACKGROUND: Annual outbreaks of acute encephalitis syndrome pose a major health burden in India. Although Japanese encephalitis virus (JEV) accounts for around 15% of reported cases, the aetiology of most cases remains unknown. We aimed to establish an enhanced surveillance network and to use a standardised diagnostic algorithm to conduct a systematic evaluation of acute encephalitis syndrome in India. METHODS: In this large-scale, systematic surveillance study in India, patients presenting with acute encephalitis syndrome (ie, acute onset of fever with altered mental status, seizure, or both) to any of the 18 participating hospitals across Uttar Pradesh, West Bengal, and Assam were evaluated for JEV (serum and cerebrospinal fluid [CSF] IgM ELISA) per standard of care. In enhanced surveillance, JEV IgM-negative specimens were additionally evaluated for scrub typhus, dengue virus, and West Nile virus by serum IgM ELISA, and for Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, dengue virus, herpes simplex virus, and enterovirus by CSF PCR across five referral laboratories. In 2017, chikungunya and Leptospira serum IgM by ELISA and Zika virus serum and CSF by PCR were also tested. FINDINGS: Of 10 107 patients with acute encephalitis syndrome enrolled in enhanced surveillance between Jan 1, 2014, and Dec 31, 2017, 5734 (57·8%) of 9917 participants with available data were male and 6179 (62·7%) of 9856 were children aged 15 years and younger. Among patients who provided a sample of either CSF or serum in enhanced surveillance, an aetiology was identified in 1921 (33·2%) of 5786 patients enrolled between 2014 and 2016 and in 1484 (34·3%) of 4321 patients enrolled in 2017. The most commonly identified aetiologies were JEV (1023 [17·7%] of 5786 patients), scrub typhus (645 [18·5%] of 3489), and dengue virus (161 [5·2%] of 3124). Among participants who provided both CSF and serum specimens, an aetiology was identified in 1446 (38·3%) of 3774 patients enrolled between 2014 and 2016 and in 936 (40·3%) of 2324 enrolled in 2017, representing a 3·1-times increase in the number of patients with acute encephalitis syndrome with an identified aetiology compared with standard care alone (299 [12·9%]; p<0·0001). INTERPRETATION: Implementation of a systematic diagnostic algorithm in an enhanced surveillance platform resulted in a 3·1-times increase in identification of the aetiology of acute encephalitis syndrome, besides JEV alone, and highlighted the importance of scrub typhus and dengue virus as important infectious aetiologies in India. These findings have prompted revision of the national testing guidelines for this syndrome across India. FUNDING: US Centers for Disease Control and Prevention.

WHO preferred product characteristics for monoclonal antibodies for passive immunization against respiratory syncytial virus (RSV) disease in infants - Key considerations for global use.

World Health Organization (WHO) preferred product characteristics describe preferences for product attributes that would help optimize value and use to address global public health needs, with a particular focus on low- and middle-income countries. Having previously published preferred product characteristics for both maternal and paediatric respiratory syncytial virus (RSV) vaccines, WHO recently published preferred product characteristics for monoclonal antibodies to prevent severe RSV disease in infants. This article summarizes the key attributes from the preferred product characteristics and discusses key considerations for future access and use of preventive RSV monoclonal antibodies.

Assessing the Full Burden of Respiratory Syncytial Virus in Young Infants in Low- and Middle-Income Countries: The Importance of Community Mortality Studies.

The Bill & Melinda Gates Foundation supported respiratory syncytial virus (RSV) mortality surveillance studies in several low- and middle-income countries to address the striking gap in community mortality burden data from these geographies. The compelling findings generated from these studies reveal a high unmeasured burden of community RSV mortality, particularly among infants aged <6 months who are the target population for RSV immunization products currently in late-stage clinical development. These findings should inform revised global RSV mortality estimates and inform policy decisions on RSV vaccine financing and prioritization at the global and national levels.

Evaluation of post-introduction COVID-19 vaccine effectiveness: Summary of interim guidance of the World Health Organization.

Phase 3 randomized-controlled trials have provided promising results of COVID-19 vaccine efficacy, ranging from 50 to 95% against symptomatic disease as the primary endpoints, resulting in emergency use authorization/listing for several vaccines. However, given the short duration of follow-up during the clinical trials, strict eligibility criteria, emerging variants of concern, and the changing epidemiology of the pandemic, many questions still remain unanswered regarding vaccine performance. Post-introduction vaccine effectiveness evaluations can help us to understand the vaccine's effect on reducing infection and disease when used in real-world conditions. They can also address important questions that were either not studied or were incompletely studied in the trials and that will inform evolving vaccine policy, including assessment of the duration of effectiveness; effectiveness in key subpopulations, such as the very old or immunocompromised; against severe disease and death due to COVID-19; against emerging SARS-CoV-2 variants of concern; and with different vaccination schedules, such as number of doses and varying dosing intervals. WHO convened an expert panel to develop interim best practice guidance for COVID-19 vaccine effectiveness evaluations. We present a summary of the interim guidance, including discussion of different study designs, priority outcomes to evaluate, potential biases, existing surveillance platforms that can be used, and recommendations for reporting results.

Younger ages at risk of Covid-19 mortality in communities of color.

More than 85% of Covid-19 mortality in high income countries is among people 65 years of age or older. Recent disaggregated data from the UK and US show that minority communities have increased mortality among younger age groups and in South Africa initial data suggest that the majority of deaths from Covid-19 are under 65 years of age. These observations suggest significant potential for increased Covid-19 mortality among younger populations in Africa and South Asia and may impact age-based selection of high-risk groups eligible for a future vaccine.

Vaccine innovations for emerging infectious diseases-a symposium report.

Vaccines have been incredibly successful at stemming the morbidity and mortality of infectious diseases worldwide. However, there are still no effective vaccines for many serious and potentially preventable infectious diseases. Advances in vaccine technology, including new delivery methods and adjuvants, as well as progress in systems biology and an increased understanding of the human immune system, hold the potential to address these issues. In addition, maternal immunization has opened an avenue to address infectious diseases in neonates and very young infants. This report summarizes the presentations from a 1-day symposium at the New York Academy of Sciences entitled "Innovative Vaccines against Resistant Infectious Diseases and Emerging Threats," held on May 20, 2019.