Report from the World Health Organization's immunization and vaccines-related implementation research advisory committee (IVIR-AC) meeting, virtual gathering, 10-13 September 2024.

The Immunization and Vaccines-related Implementation Research Advisory Committee (IVIR-AC) is the primary advisory body of the World Health Organization conducting independent reviews of immunization-related implementation research, with a primary focus on transmission and economic modeling analyses that estimate the value and impact of vaccines. From 10 to 13th September 2024, IVIR-AC convened virtually for its second of two semi-annual meetings to provide feedback and recommendations across six sessions including: pneumococcal vaccination strategies that rely on indirect protection; vaccine impact modeling for chikungunya; The Lancet Commission on strengthening the use of epidemiological modeling of emerging and pandemic infectious diseases; methods for immunization coverage estimation; setting immunization research priorities in the South-East Asian Region; and modeling evidence related to typhoid conjugate vaccine schedules. This report summarizes the sessions, proceedings, and recommendations from that meeting.

Report from the World Health Organization's immunization and vaccines-related implementation research advisory committee (IVIR-AC) ad hoc meeting, 28 June - 1 July 2024.

The World Health Organization's Immunization and Vaccines-related Implementation Research Advisory Committee (IVIR-AC) serves to independently review and evaluate vaccine-related research to maximize the potential impact of vaccination programs. From 28 June - 1 July 2024, IVIR-AC was convened for an ad hoc meeting to discuss new evidence on criteria for rubella vaccine introduction and the risk of congenital rubella syndrome. This report summarizes background information on rubella virus transmission and the burden of congenital rubella syndrome, meeting structure and presentations, proceedings, and recommendations.

Evaluating Scope and Bias of Population-Level Measles Serosurveys: A Systematized Review and Bias Assessment.

Background: Measles seroprevalence data have potential to be a useful tool for understanding transmission dynamics and for decision making efforts to strengthen immunization programs. In this study, we conducted a systematized review and bias assessment of all primary data on measles seroprevalence in low- and middle-income countries (as defined by World Bank 2021 income classifications) published from 1962 to 2021.

Methods: On 9 March 2022, we searched PubMed for all available data.

Report from the World Health Organization's immunization and vaccines-related implementation research advisory committee (IVIR-AC) meeting, virtual gathering, 26 February-1 March 2024.

The Immunization and Vaccine-related Implementation Research Advisory Committee (IVIR-AC) is the World Health Organization's key standing advisory body to conduct an independent review of research, particularly of transmission and economic modeling analyses that estimate the impact and value of vaccines. From 26th February-1st March 2024, at its first of two semi-annual meetings, IVIR-AC provided feedback and recommendations across four sessions; this report summarizes the proceedings and recommendations from that meeting. Session topics included modeling of the impact and cost-effectiveness of the R21/Matrix-M malaria vaccine, meta-analysis of economic evaluations of vaccines, a global analysis estimating the impact of vaccination over the last 50 years, and modeling the impact of different RTS,S malaria vaccine dose schedules in seasonal settings.

Progress Toward Measles Elimination - Worldwide, 2000-2022.

Measles is a highly contagious, vaccine-preventable disease that requires high population immunity for transmission to be interrupted. All six World Health Organization regions have committed to eliminating measles; however, no region has achieved and sustained measles elimination. This report describes measles elimination progress during 2000-2022.

Population-Level Risk Factors Related to Measles Case Fatality: A Conceptual Framework Based on Expert Consultation and Literature Review.

A better understanding of population-level factors related to measles case fatality is needed to estimate measles mortality burden and impact of interventions such as vaccination. This study aimed to develop a conceptual framework of mechanisms associated with measles case fatality ratios (CFRs) and assess the scope of evidence available for related indicators. Using expert consultation, we developed a conceptual framework of mechanisms associated with measles CFR and identified population-level indicators potentially associated with each mechanism.

Estimating vaccine coverage in conflict settings using geospatial methods: a case study in Borno state, Nigeria.

Reliable estimates of subnational vaccination coverage are critical to track progress towards global immunisation targets and ensure equitable health outcomes for all children. However, conflict can limit the reliability of coverage estimates from traditional household-based surveys due to an inability to sample in unsafe and insecure areas and increased uncertainty in underlying population estimates. In these situations, model-based geostatistical (MBG) approaches offer alternative coverage estimates for administrative units affected by conflict.

Estimating national-level measles case-fatality ratios in low-income and middle-income countries: an updated systematic review and modelling study.

Background: To understand the current measles mortality burden, and to mitigate the future burden, it is crucial to have robust estimates of measles case fatalities. Estimates of measles case-fatality ratios (CFRs) that are specific to age, location, and time are essential to capture variations in underlying population-level factors, such as vaccination coverage and measles incidence, which contribute to increases or decreases in CFRs. In this study, we updated estimates of measles CFRs by expanding upon previous systematic reviews and implementing a meta-regression model.

Meningococcal A conjugate vaccine coverage in the meningitis belt of Africa from 2010 to 2021: a modelling study.

Background: As of the end of 2021, twenty-four countries in the African meningitis belt have rolled out mass campaigns of MenAfriVac®, a meningococcal A conjugate vaccine (MACV) first introduced in 2010. Twelve have completed introduction of MACV into routine immunisation (RI) schedules. Although select post-campaign coverage data are published, no study currently comprehensively estimates MACV coverage from both routine and campaign sources in the meningitis belt across age, country, and time.

Progress Toward Regional Measles Elimination - Worldwide, 2000-2021.

All six World Health Organization (WHO) regions have committed to eliminating measles.* The Immunization Agenda 2021-2030 (IA2030) aims to achieve the regional targets as a core indicator of impact and positions measles as the tracer of a health system's ability to deliver essential childhood vaccines. IA2030 highlights the importance of ensuring rigorous measles surveillance systems to document immunity gaps and achieve 95% coverage with 2 timely doses of measles-containing vaccine (MCV) among children.

Exploring the subnational inequality and heterogeneity of the impact of routine measles immunisation in Africa.

Despite vaccination being one of the most effective public health interventions, there are persisting inequalities and inequities in immunisation. Understanding the differences in subnational vaccine impact can help improve delivery mechanisms and policy. We analyse subnational vaccination coverage of measles first-dose (MCV1) and estimate patterns of inequalities in impact, represented as deaths averted, across 45 countries in Africa.

Declines in Pneumonia Mortality Following the Introduction of Pneumococcal Conjugate Vaccines in Latin American and Caribbean Countries.

Background: Pneumococcal conjugate vaccines (PCVs) are recommended for use in pediatric immunization programs worldwide. Few data are available on their effect against mortality. We present a multicountry evaluation of the population-level impact of PCVs against death due to pneumonia in children < 5 years of age.

Determinants of geographical inequalities for DTP3 vaccine coverage in sub-Saharan Africa.

Childhood immunization is one of the most effective health interventions, making it a key indicator of progress towards universal health coverage. In the last decade, improvements in coverage have been made globally, however, slow progress has been documented in sub-Saharan Africa with considerable subnational variations. We explore potential drivers of equitable immunization services based on subnational DTP3 coverage estimates.

Comparison of surveillance and clinical cultures to measure the impact of infection control interventions on the incidence of methicillin-resistant and vancomycin-resistant in the hospital.

Objective: To evaluate whether clinical cultures are an appropriate surrogate for surveillance cultures to measure the effect of interventions on the incidence of MRSA and VRE in the hospital.

Design: Cross-sectional and quasi-experimental, retrospective analysis.

Setting And Population: Convenience sample of patients admitted between January 1, 2002, and June 31, 2011, to the medical intensive care unit (MICU) and surgical intensive care unit (SICU) of an acute-care hospital in the United States.

Mapping 123 million neonatal, infant and child deaths between 2000 and 2017.

Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2-to end preventable child deaths by 2030-we need consistently estimated data at the subnational level regarding child mortality rates and trends.

[Impact of the ERA and GES health programs on mortality from community-acquired pneumonia in persons aged ≥65 years in ChileImpacto do programa de saúde ERA e do GES na mortalidade por pneumonia adquirida na comunidade em indivíduos com idade acima de 65 anos no Chile].

Objective: Evaluate the impact of the Adult Respiratory Diseases (ERA) Program and the General System of Explicit Health Guarantees (GES) on mortality from community-acquired pneumonia (CAP) in persons aged ≥65 years in Chile.

Methods: In this ecological study, annual and quarterly mortality rates from CAP were calculated in persons aged 65 to 79 years and ≥80 years from 1990 to 2014. Information was gathered from the databases of Chile's Department of Health Statistics and Information and its National Statistics Institute.

Progression from latent infection to active disease in dynamic tuberculosis transmission models: a systematic review of the validity of modelling assumptions.

Mathematical modelling is commonly used to evaluate infectious disease control policy and is influential in shaping policy and budgets. Mathematical models necessarily make assumptions about disease natural history and, if these assumptions are not valid, the results of these studies can be biased. We did a systematic review of published tuberculosis transmission models to assess the validity of assumptions about progression to active disease after initial infection (PROSPERO ID CRD42016030009).

Electronically Available Comorbid Conditions for Risk Prediction of Healthcare-Associated Clostridium difficile Infection.

OBJECTIVE To analyze whether electronically available comorbid conditions are risk factors for Centers for Disease Control and Prevention (CDC)-defined, hospital-onset Clostridium difficile infection (CDI) after controlling for antibiotic and gastric acid suppression therapy use. PATIENTS Patients aged ≥18 years admitted to the University of Maryland Medical Center between November 7, 2015, and May 31, 2017. METHODS Comorbid conditions were assessed using the Elixhauser comorbidity index.

Guidance on Frequency and Location of Environmental Sampling for Acinetobacter baumannii.

We assessed various locations and frequency of environmental sampling to maximize information and maintain efficiency when sampling for Acinetobacter baumannii. Although sampling sites in closer proximity to the patient were more likely positive, to fully capture environmental contamination, we found value in sampling all sites and across multiple days. Infect Control Hosp Epidemiol 2018;39:339-342.

Collection and cryopreservation of cord blood for the treatment of hematopoietic disorders: the obstetrician's overview.

Bone marrow transplantation provides successful treatment for many diseases of the immune and hematopoietic systems. The main therapeutic ingredient in this procedure is stem cells collected from the bone marrow. Recently, it has been demonstrated that stem cells from human umbilical cord blood can serve as an alternative to bone marrow transplantation in children.

Twin transfusion syndrome: reassessment of ultrasound diagnosis.

Objective: To assess the antenatal ultrasonic diagnosis of the twin transfusion syndrome, an enigmatic disorder that results in an imbalance in the blood flow between monochorionic twins.

Study Design: Retrospective review of 16 cases of twin transfusion syndrome confirmed by placental pathology and neonatal data.

Results: A disparity in antenatal fetal weights, size difference between the two amniotic sacs and a single placenta were present in 81% (13/16) of confirmed cases.

Indomethacin in severe twin-to-twin transfusion syndrome.

Despite advances in maternal fetal medicine, the management of severe twin-to-twin transfusion syndrome in the second trimester presents a significant challenge. Presently, there is no uniformly accepted management protocol that is available for the treatment of this syndrome. We report the use of indomethacin in three cases of severe twin-to-twin transfusion syndrome in the second trimester.

A rapid visual test for predicting fetal lung maturity.

A rapid bedside test has been devised that enables an untrained observer to predict (p less than 0.001) when amniotic fluid will be greater than or equal to 0.15 at an optical density of 650 nm, lecithin/sphingomyelin ratio will be greater than or equal to 2.