Smallpox vaccine (live) suspension 0.25ml vials

According to the World Health Organization, 83,339 laboratory-confirmed cases, including 72 deaths, of mpox (formerly known as monkeypox), have been reported from 110 locations globally as of 20 December 2022, making the disease a public health concern. Most of the cases (56,171, 67.4%) were reported from countries in North America. Limited data on vaccine effectiveness in the current mpox outbreak are available. However, the modified vaccinia virus (smallpox vaccine) has been predicted to prevent or reduce the severity of the mpox infection. The present study of systematic review and meta-analysis aimed to evaluate the modified vaccinia vaccine's safety and efficacy on mpox by using reported randomized clinical trials. Following guidelines from the Cochrane Collaboration and PRISMA, multiple databases including PubMed, PLOS ONE, Google Scholar, British Medical Journal, and the U. S. National Library of Medicine were searched. Out of 13,294 research articles initially identified, 187 were screened after removing duplicates. Following the inclusion and exclusion criteria, the meta-analysis included ten studies with 7430 patients. Three researchers independently assessed the risk of bias in the included study. The pooled results suggest that the vaccinia-exposed group had fewer side effects when compared to the vaccinia naïve group (odds ratio: 1.66; 95% CI: 1.07-2.57; p = 0.03). Overall, the modified vaccinia has proven safe and effective in both vaccinia naïve and previously exposed groups, with higher efficacy in the previously exposed groups.

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BackgroundThe Democratic Republic of Congo (DRC) is recognized as the global epicenter of human Mpox. While vaccination is crucial for outbreak prevention, especially as the disease transitions from zoonotic spillover to sustained human-to-human transmission, comprehensive assessments of vaccination coverage trends across the country are notably absent from the literature. This systematic review and meta-analysis address this gap by providing the first pooled estimate of Mpox vaccine uptake and acceptance in the DRC over a 54-year period (1970-2024). Our study captures critical transitions, including the post-smallpox eradication era and recent global outbreaks, to identify temporal trends, geographic disparities in this high-risk setting.MethodsWe conducted this review following PRISMA guidelines, systematically searching PubMed, Scopus, ScienceDirect, Web of Sciences, CINAHL, and Embase. Grey literature was also searched to ensure comprehensiveness. Using random-effects models, we calculated pooled estimates for vaccine uptake and acceptance rates, with prespecified subgroup analyses examining variations by: (1) period, (2) geographic region, and (3) type of participants. We quantified heterogeneity using I² statistics and conducted meta-regression to identify predictors of vaccination coverage heterogeneity. A p-value ˂ 0.05 was considered statistically significant.ResultsOur analysis revealed a pooled Mpox vaccine uptake of 20.01% (95% CI: 7.45-43.75) with high heterogeneity (I² = 99.4%, p ConclusionDespite moderate acceptance rates, actual Mpox vaccination uptake in the DRC remains low, with worsening coverage in recent years and substantial regional inequities. These findings underscore the urgent need for context-specific interventions to bridge the intention-action gap in this high-risk setting.

Abstract licence: CC BY-NC-ND

Mpox is a zoonotic disease caused by the monkeypox virus (MPXV) that became a global health concern following the 2022 outbreak. It poses a significant threat to immunocompromised individuals, children, and pregnant persons. Disease spread in the Democratic Republic of the Congo (DRC) and propagation to other countries has led to recent declarations of public health emergencies. Smallpox vaccination cessation has further heightened population vulnerability to MPXV. In response, MVA-BN and LC16m8, vaccinia-based vaccines originally developed for smallpox, have been repurposed for mpox, demonstrating promising safety and immunogenicity profiles. Despite these advancements, challenges remain in vaccine distribution and in understanding vaccine efficacy across populations, particularly in key at-risk groups. Available evidence remains fragmented and largely derived from adult populations, with limited data in pregnant persons, children, and adolescents. This living systematic review (LSR) aims to evaluate the safety, efficacy, effectiveness, and immunogenicity of mpox vaccines across populations, with particular focus on pregnant persons, children, and adolescents. We aim to conduct a LSR and meta-analysis based on biweekly searches of medical databases and clinical trial registries from inception to the current date to systematically identify relevant studies of mpox vaccines across populations. Pairs of reviewers will independently select eligible studies, extract data, and assess the risk of bias. We will include randomized clinical trials, quasi-experimental studies, cohort studies, case-control studies, cross-sectional studies, and case reports. Primary outcomes will include safety, efficacy/effectiveness, and immunogenicity of mpox vaccines across populations, including outcomes in pregnant persons (with neonatal outcomes), children, and adolescents. Meta-analyses will be conducted, including prespecified subgroup and sensitivity analyses. We will use the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach to assess the certainty of evidence. This LSR will synthesize evidence on mpox vaccines across populations, with particular focus on pregnant persons, children, and adolescents. As mpox continues to pose a global threat, particularly in endemic and low-resource settings, timely and rigorous assessment of vaccine performance is essential to guide equitable immunization policies and maternal-child health strategies. International Prospective Register of Systematic Reviews (PROSPERO): CRD42024554330 (pregnant persons) and CRD42024556977 (children and adolescents).

Abstract licence: CC BY-NC-ND

BackgroundMpox is a re-emerging zoonotic infection caused by an Orthopoxvirus closely related to smallpox. The 2022-23 global outbreak prompted rapid use of vaccinia-based vaccines, historically developed for smallpox and those of the latest generation used for mpox prevention. Assessing their safety and effectiveness in pregnant persons and children is critical to guide policies protecting populations at an elevated risk of severe illness.ObjectiveThis study assessed the safety and effectiveness of mpox and historical smallpox vaccines, administered during pregnancy and childhood.MethodsWe conducted a living systematic review and meta-analysis (PROSPERO CRD42024591322/CRD42024586205) following Cochrane, World Health Organization, and Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) standards. We searched biweekly across major databases, trial registries, preprints, and gray literature (inception to September 2025) for studies evaluating the safety and effectiveness of vaccinia-based smallpox vaccines, including historical (first- and second-generation) and modern (third-generation) vaccines, in maternal and pediatric populations. Reviewers independently conducted study selection, data extraction, and risk-of-bias assessment. Meta-analyses employed random-effects models, and results are presented through an interactive dashboard and a living platform.ResultsWe included 27 clinical studies (1949-2025), involving 1,406,771 children/adolescents (eight studies) and 11,482 pregnant persons (19 studies). Most maternal data came from first-generation vaccines (Lister, Finnish, Dryvax, APSV). These vaccines were not associated with an increased risk of spontaneous abortion (risk ratio [RR] 1.02, 95% confidence interval [CI] 0.70-1.48), stillbirth (RR 1.02, 95% CI 0.70-1.48), or preterm birth (RR 1.08, 95% CI 0.78-1.50), but were linked to a higher risk of congenital anomalies (RR 1.25, 95% CI 1.01-1.54). Fifty-two fetal vaccinia cases were reported globally up to 1978, with none since. Evidence on second- (ACAM2000) and third-generation (MVA-BN) non-replicating vaccines remains limited. In children, serious adverse events were rare, and MVA-BN caused only mild self-limiting reactions. No study assessed vaccine effectiveness in pregnant persons, while limited pediatric data suggested possible protection after post-exposure prophylaxis.ConclusionsVaccinia-based vaccines appear generally safe in pregnancy and children. However, evidence on the safety and effectiveness of third-generation mpox vaccines is still scarce. High-quality prospective studies and strengthened pharmacovigilance are urgently needed to inform policy and clinical decision making.

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Background: From smallpox variolation practiced in imperial China in the 10th century to the messenger RNA vaccines deployed in 2020, vaccination ranks among the most effective public health interventions in the history of medicine. Nevertheless, the rare but clinically significant occurrence of serious adverse events following immunization (AEFI) remains a major challenge for contemporary pharmacovigilance. Identifying the individual determinants of susceptibility represents a leading scientific and ethical priority. Objective. To critically analyze the available scientific literature in order to determine the extent to which three families of host factors the HLA immunogenetic profile, undiagnosed mild immunodeficiencies, and chronic inflammatory comorbidities contribute to the occurrence of serious AEFI, and to identify biomarkers and prevention strategies likely to improve vaccine safety. Methods. Narrative and critical literature review. The PubMed/MEDLINE, Scopus, Web of Science, and Google Scholar databases were searched for the period 1990–2025. Original articles, systematic reviews, meta-analyses, and case series describing a link between vaccination and HLA profiles, mild immunodeficiencies, or inflammatory comorbidities were included. Editorials without data and exclusively animal studies were excluded. Results. The data converge toward an integrative model in which serious AEFI result from the interaction between a platform-specific vaccine stimulus and a permissive host background. Certain HLA alleles (HLA-A*03:01, HLA-DRB1*11:04, HLA-DQB1*06) modulate antigen presentation and predispose to inadequate or autoreactive immune responses. Mild immunodeficiencies, particularly type I interferon deficits and dysregulation of regulatory T lymphocytes, compromise immune-braking mechanisms. Chronic inflammatory comorbidities, diabetes, hypertension, pre-existing autoimmune diseases raise the baseline level of inflammation and lower the threshold for triggering a pathological response. Four etiological categories of serious AEFI are identified: (A) with a dominant cause linked to the vaccine platform; (B) multifactorial metabolic; (C) mixed, resulting from the interaction between a vaccine mechanism and a latent host susceptibility; (D) with a mechanism not yet elucidated. Conclusion. The systematic integration of HLA typing, type I interferon assays, and cytokine profiling into pharmacovigilance algorithms would refine individual causal assessment and pave the way for personalized vaccination. Multicenter prospective studies, including African populations underrepresented in the literature, are needed to validate these biomarkers in clinical practice.

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