Background: A recurrent tuberculosis (TB) episode results from exogenous reinfection or relapse after cure. The use of genotyping allows the distinction between both. Methods: We did a systematic review and meta-analysis, using four databases to search for studies in English, French and Spanish published between 1 January 1980 and 30 September 2020 that assessed recurrences after TB treatment success and/or differentiated relapses from reinfections using genotyping. We calculated person years of follow-up and performed random-effects model meta-analysis for estimating pooled recurrent TB incidence rates and proportions of relapses and reinfections. We performed subgroup analyses by clinical–epidemiological factors and by methodological study characteristics. Findings: The pooled recurrent TB incidence rate was 2.26 per 100 person years at risk (95% CI 1.87 to 2.73; 145 studies). Heterogeneity was high (I ² =98%). Stratified pooled recurrence rates increased from 1.47 (95% CI 0.87 to 2.46) to 4.10 (95% CI 2.67 to 6.28) per 100 person years for studies conducted in low versus high TB incidence settings. Background HIV prevalence, treatment drug regimen, sample size and duration of follow-up contributed too. The pooled proportion of relapses was 70% (95% CI 63% to 77%; I²=85%; 48 studies). Heterogeneity was determined by background TB incidence, as demonstrated by pooled proportions of 83% (95% CI 75% to 89%) versus 59% (95% CI 42% to 74%) relapse for studies from settings with low versus high TB incidence, respectively. Interpretation: The risk of recurrent TB is substantial and relapse is consistently the most frequent form of recurrence. Notwithstanding, with increasing background TB incidence the proportion of reinfections increases and the predominance of relapses among recurrences decreases. PROSPERO registration number: CRD42018077867

Background The rate of pulmonary tuberculosis (TB) recurrence is substantial. Identifying risk factors can support the development of prevention strategies. Methods We retrieved studies published between 1 January 1980 and 31 December 2022 that assessed factors associated with undifferentiated TB recurrence, relapse or reinfection. For factors reported in at least four studies, we performed random-effects meta-analysis to estimate a pooled relative risk (RR). We assessed heterogeneity, risk of publication bias and certainty of evidence. Results We included 85 studies in the review; 81 documented risk factors for undifferentiated recurrence, 17 for relapse and 10 for reinfection. The scope for meta-analyses was limited given the wide variety of factors studied, inconsistency in control for confounding and the fact that only few studies employed molecular genotyping. Factors that significantly contributed to moderately or strongly increased pooled risk and scored at least moderate certainty of evidence were: for undifferentiated recurrence, multidrug resistance (MDR) (RR 3.49; 95% CI 1.86 to 6.53) and fixed-dose combination TB drugs (RR 2.29; 95% CI 1.10 to 4.75) in the previous episode; for relapse, none; and for reinfection, HIV infection (RR 4.65; 95% CI 1.71 to 12.65). Low adherence to treatment increased the pooled risk of recurrence 3.3-fold (95% CI 2.37 to 4.62), but the certainty of evidence was weak. Conclusion This review emphasises the need for standardising methods for TB recurrence research. Actively pursuing MDR prevention, facilitating retention in treatment and providing integrated care for patients with HIV could curb recurrence rates. The use of fixed-dose combinations of TB drugs under field conditions merits further attention. PROSPERO registration number CRD42018077867.

Background/Objective: Historically, immunization programs have focused on infants, children, and women of reproductive age. COVID-19 vaccination prompted countries to vaccinate adults. The objective of this manuscript is to provide a global overview of adult immunization policies post COVID-19 pandemic. Methods: We summarized WHO Strategic Advisory Group of Experts on Immunization (SAGE) recommendations by adult group and analyzed the data reported in 2024 (2023) by WHO Member States (MS) via the WHO/UNICEF electronic Joint Reporting Form on Immunization (eJRF) on national immunization schedules, and from other sources by WHO region and income group. Results: WHO policy recommendations exist for most of the licensed vaccines targeting adults; however, the inclusion in national immunization schedules is higher in high-income (HICs) and middle-income (MICs) countries. For pregnant women, 90% of MS reported vaccination against COVID-19 (65% in low-income countries [LICs]), 63% against tetanus-containing vaccines (73% in LICs), 57% against influenza (4% in LICs), and 21% against pertussis-containing vaccines (all MICs and HICs). For health workers, 91% against COVID-19 (92% in LICs), 59% against influenza (4% in LICs), and 25% against hepatitis B (10% in LICs). For adults with chronic diseases, COVID-19 vaccination data were not available, 58% against influenza, and 23% against pneumococcal disease. For older adults, more than 90% of MS across all income groups reported COVID-19 vaccination, 59% against influenza (8% of LICs versus 89% of HICs), 17% against pneumococcal, and 7% against herpes zoster (HZ). Conclusion: The disparities in adult immunization policies across income groups highlight the need to improve access and strengthen vaccination efforts. A life course approach is essential to maximize the full potential of immunization across all ages.

The goal of this qualitative research study, part of an interdisciplinary project, was to understand the overlapping geographical distribution of COVID-19 and tuberculosis burden in Lima. Using an ethnographic approach, we applied the concept of disease situations to explore how inhabitants' social and spatial situatedness affected their capacity to respond to the pandemic. Our results show that for some populations in Lima, the risk to develop COVID-19 did not emerge suddenly; it could be traced back to situations of living under subsistence models, relying on unstable sources of income, facing food insecurity, depending on certain mechanisms of social protection, residing in precarious living environments and lacking access to quality health care. These populations did not only have less resources to adjust to changes in daily life induced by the pandemic; they were also forced to constantly weigh the risk of COVID-19 against other pressing needs and potentially face increased risks when control measures were actually followed. Pre-existing social networks played fundamental roles as sources of emotional and material support. The lens of disease situations can help to identify and explain spatial and social configurations that enhance vulnerability, as well as resilience mechanisms that are in place to deal with crises. This perspective could inform the design of contextualised prevention and response strategies around health risks in cities as diverse as Lima, whilst building on existing resources at local levels.

Background: Historically, immunization programmes have focused on infants, children, and women of reproductive age. COVID-19 vaccination prompted countries to vaccinate adults. This manuscript provides a global overview of adult immunization post COVID-19 pandemic. Methods: We summarized WHO Strategic Advisory Group of Experts on Immunization (SAGE) recommendations by adult group and analyzed the data reported in 2024 (2023) by WHO Member States (MS) via the WHO/UNICEF electronic Joint Reporting Form on Immunization (eJRF) on national immunization schedules, and from other sources by WHO region and income group. Results: WHO policy recommendations exist for most of the licensed vaccines targeting adults; however, the inclusion in national immunization schedules is higher in high-income (HICs) and middle-income (MICs) countries. For pregnant women, 90% of MS reported vaccination against COVID-19 (65% in low-income countries [LICs]), 63% against tetanus-containing vaccines (73% in LICs), 57% against influenza (4% in LICs), and 21% against pertussis-containing vaccines (all MICs and HICs). For health workers, 91% against COVID-19 (92% in LICs), 59% against influenza (4% in LICs), and 25% against hepatitis B (10% in LICs). For adults with chronic diseases, COVID-19 vaccination data were not available, 58% against influenza, and 23% against pneumococcal disease. For older adults, more than 90% of MS across all income groups reported COVID-19 vaccination, 59% against influenza (8% of LICs versus 89% of HICs), 17% against pneumococcal, and 7% against herpes zoster. Conclusion: The disparities in adult immunization policies across income groups highlight the need to improve access and strengthen vaccination efforts. A life course approach is essential to maximize the full potential of immunization across all ages.

Background/Objectives: The global rollout of COVID-19 vaccines faced significant implementation challenges: limited adult immunization infrastructure, particularly in low- and middle-income countries; rapidly shifting viral epidemiology driven by emerging variants; and widespread vaccine misinformation that fueled hesitancy. Achieving the high coverage necessary to curb transmission required urgent attention to demand-side barriers, making the identification of effective interventions a critical public health priority. This systematic review synthesized global evidence on communication, behavioral, and health systems interventions to increase COVID-19 vaccine demand and uptake. The review assessed intervention effectiveness across diverse population groups and settings and identified lessons to inform the design of adult vaccination programs and future outbreak response. Methods: Between March 2022 and July 2024, we performed a systematic search in PubMed, Scopus, and Global Index Medicus, for COVID-19 demand and uptake studies published after December 2020, with no language or geographic restrictions. Eligible papers were those that reported intervention studies with quantitative comparative outcomes on vaccination attitudes, appointment rates, uptake, or coverage following an intervention. Study quality was assessed using adapted Critical Appraisal Skills Program (CASP) criteria. Studies were categorized into nine intervention approaches, based on an adapted communication and service-delivery taxonomy. Interventions operated at individual, systems, and structural levels. A narrative synthesis was combined with vote counting of studies with positive findings to understand what intervention approaches were effective. and under what conditions. Results: From over 23,000 records, 57 studies from 27 countries met inclusion and quality criteria. Most studies were conducted in high-income countries. Overall, 70% of studies reported positive findings on at least one vaccination outcome. Educational interventions were the most frequently studied approach and were most effective when delivered through multiple channels by trusted messengers and integrated with complementary strategies, rather than as standalone information provision. Reminder and nudge interventions showed mixed results, performing best when embedded within multicomponent approaches that addressed both logistical and attitudinal barriers. Access-enhancing and service delivery interventions demonstrated the most consistent evidence of effectiveness, with nine of ten studies reporting positive outcomes; successful approaches included on-site vaccination, mobile units, pharmacy and community health worker delivery, and integration into existing healthcare touchpoints. Vaccine mandates demonstrated the strongest and most consistent effects on coverage at scale, though their coercive mechanism raises ethical considerations around autonomy, equity, and public trust. Conclusions: Improving COVID-19 vaccine uptake requires interventions that simultaneously address knowledge gaps, practical barriers to access, and structural determinants of vaccination behavior. The most effective strategies combined educational, behavioral, and service delivery components tailored to the needs and barriers of specific groups. Policymakers should prioritize access-enhancing and systems-strengthening interventions as a foundation, supplement these with targeted communication delivered by trusted messengers, and reserve mandate-based approaches for situations where less restrictive measures have proven insufficient. These findings have relevance beyond COVID-19, offering transferable lessons for adult immunization programs and future outbreak preparedness.