Effectiveness of one dose of MVA-BN smallpox vaccine against mpox in England using the case-coverage method: an observational study

Equivalence of freeze-dried and liquid-frozen formulations of MVA-BN as smallpox and mpox vaccine

Modified Vaccinia Ankara Bavarian Nordic (MVA-BN) as a smallpox and mpox vaccine has been approved in its liquid-frozen (LF) formulation in the US, Canada, and EU. A freeze-dried (FD) formulation may offer additional benefits, such as a longer shelf life and reduced dependence on cold chain storage and transport. In a phase 2 clinical trial, 651 vaccinia-naïve participants were vaccinated with two doses of MVA-BN LF or FD, 4 weeks apart. The objectives were to compare MVA-BN FD with LF in terms of vaccine-induced immune responses, safety, and reactogenicity. Non-inferiority of the immune response was assessed by the 95% CI of the geometric mean ratios. Both formulations induced robust vaccinia-specific humoral and cellular immune responses. At peak humoral responses (Week 6), geometric means of total antibody titers were 1096 (95% CI 1013, 1186) from the FD group and 877 (95% CI 804, 956) from the LF group, achieving the primary endpoint of non-inferiority of MVA-BN FD compared to MVA-BN LF. At peak cellular responses (Week 2), geometric means of T cell spot forming units were 449 (95% CI 341, 590) from the FD group and 316 (95% CI 234, 427) from the LF group. Both formulations of MVA-BN were well tolerated, with similar unsolicited AEs and solicited systemic reactions in both groups but slightly more local reactions in the FD group. No vaccine-related serious adverse events (SAEs) or vaccine-related AE of special interest were reported. The FD formulation of MVA-BN was shown to be equivalent to MVA-BN LF.

Vaccine effectiveness of 3rd generation mpox vaccines against mpox and disease severity: A systematic review and meta-analysis

INTRODUCTION

Before the global mpox outbreak which began in 2022, the real-world vaccine effectiveness (VE) of mpox vaccines was unknown. We quantified the VE in the global population of 3rd generation or later mpox vaccines (MVA-BN, LC16m8, OrthopoxVac) compared with unvaccinated or other vaccinated states for infection, hospitalization and death. VE was stratified by 1-dose and 2-doses and post-exposure prophylaxis (PEP).

METHODS

Studies were included if they measured vaccine efficacy or effectiveness in humans. Animal studies and immunogenicity studies were excluded. MEDLINE, Web of Science, Google Scholar, Embase, MedRxiv and grey literature were searched from January 1st, 1970, with the last search run on November 3, 2023 (Prospero, CRD42022345240). Risk of publication bias was assessed via funnel plots and Egger's test, and study quality via Newcastle-Ottawa scales.

RESULTS

A total of 11,892 records were identified via primary search, 3,223 via citation chasing. Thirty-three studies were identified of 3rd generation vaccines, 32 of which were MVA-BN. Two additional studies were re-analysis of existing data. Most of these studies were focused on gay, bisexual, or other men who have sex with men between the ages of 18-49 in May to October of 2022. VE of 1 dose of MVA-BN was 76% (95%CI 64-88%) from twelve studies. VE of 2 doses was 82% (95%CI 72-92%) from six studies. VE of MVA-BN PEP against mpox was 20% (95%CI -24-65%) from seven studies. All VE are calculated from random effects estimates. 18/33(55%) studies were rated as poor, 3/33(9%) as fair and 12/33(36%) as good. Studies included in the meta-analysis had higher quality: 11/16 (69%) were rated as good quality.

CONCLUSION

Both 1 and 2 doses of MVA-BN are highly effective at preventing mpox. Effectiveness estimates, specifically of PEP are limited by immortal time bias, predominant mode of mpox transmission, and real-world vaccine timing of administration.

Mpox Epidemiology and Vaccine Effectiveness, England, 2023

Reported mpox cases in England continued at a low but steady frequency during 2023. Of 137 cases reported in 2023, approximately half were acquired overseas and half were in vaccinated persons. Estimated effectiveness of 2-dose vaccine was 80%, and no vaccinated mpox patient was hospitalized.

Real-world safety data for MVA-BN: Increased frequency of syncope following intradermal administration for immunization against mpox disease

BACKGROUND

MVA-BN vaccine (Jynneos, Imvamune, Imvanex) was used widely in the 2022 mpox outbreak. This experience provides real-world evidence about the vaccine's safety, particularly regarding intradermal use.

METHODS

Bavarian Nordic's global safety database was searched for all adverse events following immunization (AEFIs) with MVA-BN. AEFI numbers were compared among administration routes. Selected events and administered doses were graphed over the mpox outbreak period.

RESULTS

A total of 9585 AEFIs have been reported. The rate of myocarditis or pericarditis was <1 per 100,000 doses administered. Eighty-nine cases of syncope, fainting, or loss of consciousness were reported. This number rose after the August 2022 US emergency use authorization for intradermal administration, as did the proportion of all syncope AEFIs reported following intradermal administration (78,7 %).

CONCLUSION

Real-world data from large-scale administration of MVA-BN has confirmed the vaccine's established safety profile when administered subcutaneously. Intradermal administration is likely associated with increased syncopal event frequency.

Effectiveness of modified vaccinia Ankara-Bavarian Nordic vaccine against mpox infection: emulation of a target trial

OBJECTIVE

To estimate the real world effectiveness of modified vaccinia Ankara-Bavarian Nordic (MVA-BN) vaccine against mpox infection.

DESIGN

Emulation of a target trial.

SETTING

Linked databases in Ontario, Canada.

PARTICIPANTS

9803 men aged ≥18 years with a history of being tested for syphilis and a laboratory confirmed bacterial sexually transmitted infection (STI) in the previous year, or who filled a prescription for HIV pre-exposure prophylaxis in the previous year. On each day between 12 June 2022 and 27 October 2022, those who had been vaccinated 15 days previously were matched 1:1 with unvaccinated men by age, geographical region, past HIV diagnosis, number of bacterial STI diagnoses in the previous three years, and receipt of any non-MVA-BN vaccine in the previous year.

MAIN OUTCOME MEASURE

The main outcome measure was vaccine effectiveness ((1-hazard ratio)×100) of one dose of subcutaneously administered MVA-BN against laboratory confirmed mpox infection. A Cox proportional hazards model was used to estimate hazard ratios to compare the rate of laboratory confirmed mpox between the two groups.

RESULTS

3204 men who received the vaccine were matched to 3204 unvaccinated controls. A total of 71 mpox infections were diagnosed, with 0.09 per 1000 person days (95% confidence interval (CI) 0.05 to 0.13) in the vaccinated group and 0.20 per 1000 person days (0.15 to 0.27) in the unvaccinated group over the study period of 153 days. Estimated vaccine effectiveness of one dose of MVA-BN against mpox infection was 58% (95% CI 31% to 75%).

CONCLUSION

The findings of this study, conducted in the context of a targeted vaccination programme and evolving outbreak of mpox, suggest that one dose of MVA-BN is moderately effective in preventing mpox infection.

Effectiveness of a single dose of JYNNEOS vaccine in real world: A systematic review and meta-analysis

Background

Mpox infection is a zoonotic illness that resembles smallpox. Vaccination is widely regarded as a vital effective method of preventing mpox, however, there is lack of consensus of effectiveness of a single dose of mpox vaccine in the current 2022-2023 outbreak. We pooled data from real-world studies to evaluate the efficacy of the JYNNEOS vaccination given as a single dosage.

Method

We carried out a thorough literature search in PubMed, Web of Science, and Scopus up until August 2023. We estimated the pooled vaccine effectiveness (VE) for mpox using inverse variance method in a random-effects meta-analysis. We expressed the results as VE, 95% confidence interval (95% CI), and 95% prediction interval (95% PI) using R v4.3.0. We assessed influence, heterogeneity contribution, and influence of studies using several tests and conducted sensitivity analysis accordingly. We used Doi plot and Luis Furuya-Kanamori (LFK) index to evaluate publication bias.

Results

With a total sample size of 35,326 individuals, we involved 11 studies in the meta-analysis. The VE of a single dose of JYNNEOS vaccine was 78.23% (95% CI: 62.79%-87.27%) by pooling data of 24,784 individuals over seven studies. The findings were heterogenous with a 95% PI of -32.14% to 96.41% depicting the expected range of VE in similar settings. Notably, VE increased to 83.02% (74.62%-88.64%) with a prediction interval of (44.67%-94.79) after sensitivity analysis by leaving out outliers. The results were robust in light of several sensitivity analyses. An asymmetric Doi plot with LFK index of -2.25 showed potential publication bias. Pooled prevalence of mpox infection among vaccinated individuals (breakthrough infection) in six studies was 2.19% (0.37%-5.32%).

Conclusion

The present findings provide compelling evidence that a single dose of JUNNEOS vaccine can protect recipients from mpox infection. With a 78.23% estimated efficacy rate, the vaccine is thought to be a useful tool in preventing further spread of mpox. However, more research and ongoing surveillance are required to fully understand the reasons behind breakthrough infections and to improve immunization strategies for better protection against mpox.

Effectiveness of JYNNEOS vaccine against symptomatic mpox disease in adult men in Los Angeles County, August 29, 2022 to January 1, 2023

We describe real-world estimates of JYNNEOS vaccine effectiveness (VE) against symptomatic mpox in Los Angeles County (LAC). We conducted a retrospective cohort study of men aged ≥18 years residing in LAC who were at risk for mpox and eligible for the JYNNEOS vaccine from 5/19/2022 to 1/1/2023. Case demographics and route of JYNNEOS administration were obtained through vaccine administration data systems. HIV and sexually transmitted infection (STI) status was obtained through disease reporting systems for HIV and STI diagnoses in LAC. To estimate VE, we calculated weekly incidence of confirmed mpox for unvaccinated, partially vaccinated (episode date ≥14 days after first dose), and fully vaccinated (episode date ≥14 days after second dose) cohorts starting on 8/29/2022, when fully vaccinated coverage exceeded 3 %, and ending on 1/1/2023. Overall, 2,171 men had confirmed mpox, and 1,002 (46 %) of those were persons living with diagnosed HIV (PLWDH). 2,019 (93 %) mpox cases were unvaccinated, 114 (5 %) were partially vaccinated and 38 (2 %) were fully vaccinated. VE was 69 % (95 % CI 59-77) for partially vaccinated and 84 % (95 % CI 80-87) for fully vaccinated individuals. Among PLWDH, VE was 72 % (95 % CI 57-82) for fully vaccinated and 28 % (95 % CI -96 to 73) VE for partially vaccinated individuals. Among persons not living with diagnosed HIV, VE was 88 % (95 % CI 86-90) for fully vaccinated and 80 % (95 % CI 76-83) for partially vaccinated individuals. Of 111 individuals hospitalized with mpox, one was partially vaccinated, and the remaining were unvaccinated. Our results align with other published studies that reported that two doses of the JYNNEOS vaccine provided significant protection against symptomatic mpox.

A Comparative Evaluation of Three Diagnostic Assays for the Detection of Human Monkeypox

Accurate and early diagnosis of monkeypox virus (MPXV) is crucial for controlling epidemics and treating affected individuals promptly. This study aimed to assess the analytical and clinical performance of the MolecisionTM Monkeypox Virus qPCR Assay, Biorain Monkeypox Virus ddPCR Assay, and MAGLUMI® Monkeypox Virus Ag (chemiluminescence immunoassay, CLIA) Assay. Additionally, it aimed to compare the clinical application of antigen and nucleic acid assays to offer insights into using commercial monkeypox assay kits. Specimens from 117 clinical patients, serial diluted virus cell culture supernatant, and artificially created positive samples were tested to evaluate the performance of these assay kits for MPXV diagnostics. The Biorain Monkeypox Virus ddPCR Assay had a limit of detection (LoD) of 3.89 CCID50/mL, while the MolecisionTM Monkeypox Virus qPCR Assay had an LoD of 15.55 CCID50/mL. The MAGLUMI® Monkeypox Virus Ag (CLIA) Assay had an LoD of 0.500 pg/mL. The accuracy of the MolecisionTM Monkeypox Virus qPCR Assay was comparable to the Biorain Monkeypox Virus ddPCR Assay, and the MAGLUMI® Monkeypox Virus Ag (CLIA) Assay demonstrated high sensitivity. The specificity of all three MPXV diagnostic assays for clinical specimens with potential cross-reacting substances was 100%. In conclusion, this study provides valuable insights into the clinical application of monkeypox assays, supporting efforts to mitigate and control the spread of monkeypox.

Multi-omics characterization of the monkeypox virus infection

Multiple omics analyzes of Vaccinia virus (VACV) infection have defined molecular characteristics of poxvirus biology. However, little is known about the monkeypox (mpox) virus (MPXV) in humans, which has a different disease manifestation despite its high sequence similarity to VACV. Here, we perform an in-depth multi-omics analysis of the transcriptome, proteome, and phosphoproteome signatures of MPXV-infected primary human fibroblasts to gain insights into the virus-host interplay. In addition to expected perturbations of immune-related pathways, we uncover regulation of the HIPPO and TGF-β pathways. We identify dynamic phosphorylation of both host and viral proteins, which suggests that MAPKs are key regulators of differential phosphorylation in MPXV-infected cells. Among the viral proteins, we find dynamic phosphorylation of H5 that influenced the binding of H5 to dsDNA. Our extensive dataset highlights signaling events and hotspots perturbed by MPXV, extending the current knowledge on poxviruses. We use integrated pathway analysis and drug-target prediction approaches to identify potential drug targets that affect virus growth. Functionally, we exemplify the utility of this approach by identifying inhibitors of MTOR, CHUK/IKBKB, and splicing factor kinases with potent antiviral efficacy against MPXV and VACV.

Effectiveness of historical smallpox vaccination against mpox clade II in men in Denmark, France, the Netherlands and Spain, 2022

BackgroundIn 2022, a global monkeypox virus (MPXV) clade II epidemic occurred mainly among men who have sex with men. Until early 1980s, European smallpox vaccination programmes were part of worldwide smallpox eradication efforts. Having received smallpox vaccine > 20 years ago may provide some cross-protection against MPXV.AimTo assess the effectiveness of historical smallpox vaccination against laboratory-confirmed mpox in 2022 in Europe.MethodsEuropean countries with sufficient data on case vaccination status and historical smallpox vaccination coverage were included. We selected mpox cases born in these countries during the height of the national smallpox vaccination campaigns (latest 1971), male, with date of onset before 1 August 2022. We estimated vaccine effectiveness (VE) and corresponding 95% CI for each country using logistic regression as per the Farrington screening method. We calculated a pooled estimate using a random effects model.ResultsIn Denmark, France, the Netherlands and Spain, historical smallpox vaccination coverage was high (80-90%) until the end of the 1960s. VE estimates varied widely (40-80%, I2 = 82%), possibly reflecting different booster strategies. The pooled VE estimate was 70% (95% CI: 23-89%).ConclusionOur findings suggest residual cross-protection by historical smallpox vaccination against mpox caused by MPXV clade II in men with high uncertainty and heterogeneity. Individuals at high-risk of exposure should be offered mpox vaccination, following national recommendations, regardless of prior smallpox vaccine history, until further evidence becomes available. There is an urgent need to conduct similar studies in sub-Saharan countries currently affected by the MPXV clade I outbreak.

Mpox in people with HIV: A narrative review

OBJECTIVE

The 2022 global mpox outbreak disproportionately impacted people living with HIV. This review explores recent evidence on mpox in this group, focusing on clinical presentation, complications, treatment modalities and vaccine strategies.

RECENT FINDINGS

Recent studies have suggested that people with HIV diagnosed with mpox have a greater risk of proctitis and hospitalization compared with people without HIV. In addition, those with advanced immunosuppression face an elevated risk of severe mpox infection, which can lead to mortality. Comprehensive and prompt supportive care using antiretrovirals and mpox antivirals is crucial in this group. Although results from randomized clinical trials are still forthcoming, recent studies suggest that early initiation of tecovirimat can prevent disease progression in people with HIV. The non-replicative attenuated smallpox vaccine is well tolerated and effective in preventing monkeypox virus infections in people with HIV. Further studies are needed regarding long-term vaccine effectiveness for this population.

CONCLUSION

Evaluating the risk of severe mpox in people living with HIV requires assessing the level of immune suppression and viral control. Universal access to vaccination is imperative to prevent the resurgence of future outbreaks.

Investigation of an Mpox Outbreak Affecting Many Vaccinated Persons in Chicago, Illinois-March 2023-June 2023

BACKGROUND

After months of few mpox cases, an increase in cases was reported in Chicago during May 2023, predominantly among fully vaccinated (FV) patients. We investigated the outbreak scope, differences between vaccinated and unvaccinated patients, and hypotheses for monkeypox virus (MPXV) infection after vaccination.

METHODS

We interviewed patients and reviewed medical records to assess demographic, behavioral, and clinical characteristics; mpox vaccine status; and vaccine administration routes. We evaluated serum antibody levels after infection and compared patient viral genomes with MPXV sequences in available databases. We discussed potential vaccine compromise with partners who manufactured, handled, and administered the vaccine associated with breakthrough infections.

RESULTS

During 18 March-27 June 2023, we identified 49 mpox cases; 57% of these mpox patients were FV. FV patients received both JYNNEOS doses subcutaneously (57%), intradermally (7%), or via heterologous administration (36%). FV patients had more median sex partners (3; interquartile range [IQR] = 1-4) versus not fully vaccinated patients (1; IQR = 1-2). Thirty-six of 37 sequenced specimens belonged to lineage B.1.20 of clade IIb MPXV, which did not demonstrate any amino acid changes relative to B.1, the predominant lineage from May 2022. Vaccinated patients demonstrated expected humoral antibody responses; none were hospitalized. No vaccine storage excursions were identified. Approximately 63% of people at risk for mpox in Chicago were FV during this period.

CONCLUSIONS

Our investigation indicated that cases were likely due to frequent behaviors associated with mpox transmission, even with relatively high vaccine effectiveness and vaccine coverage. Cases after vaccination might occur in similar populations.

Willingness to receive mpox vaccine among men who have sex with men: a systematic review and meta-analysis

BACKGROUND

Since May 2022, mpox outbreaks have been occurring in non-mpox endemic areas, with the main population affected being men who have sex with men (MSM). Outbreak prevention and control depend not only on the effectiveness of vaccines but also on people's willingness to receive these vaccines. Currently, there is lack of synthesis on the overall rates and influence factors of MSMs' willingness to vaccinate against mpox. Therefore, we systematically reviewed studies that assessed the willingness of MSM to receive mpox vaccine.

METHODS

Studies reporting mpox vaccination intentions among MSM were included by searching five databases (PubMed, Web of Science, EMBASE, CINAHL, and SCOPUS) from inception to May 12, 2024. The quality of the included literature was assessed using Joanna Briggs Institute's critical appraisal tool. The data analysis software is Stata17. The systematic review has been registered with Prospero (registration ID: CRD42023452357).

RESULTS

Twenty cross-sectional studies were included in the review. Meta-analysis results showed that the pooled willingness rate of vaccinate against mpox was 77.0% (95% CI: 73-81%, I2 = 99.4%). According to subgroup analysis, study countries (P = 0.002), research sample size (P = 0.001), and whether participants were infected with HIV (P = 0.002) may be sources of heterogeneity. The results of the meta-analysis of influencing factors showed that more number of sexual partners (OR: 2.24, 95%CI: 1.86-2.69), pre-exposure prophylaxis use (OR: 6.04, 95%CI: 4.80-7.61), history of sexually transmitted infections (OR: 2.96, 95%CI: 2.33-3.76), confidence in the vaccine's effectiveness (OR: 2.79, 95%CI: 2.04-3.80) and safety (OR: 10.89, 95%CI: 5.22-22.72), fear of mpox infection (OR: 2.47, 95%CI: 2.11-2.89) and epidemics (OR: 2.87, 95%CI: 2.22-3.70), high mpox knowledge (OR: 2.35, 95%CI: 1.51-3.66), and the belief that people at high risk should be prioritized for vaccination (OR: 3.09, 95%CI: 1.40-6.84) were the facilitators of vaccine willingness. In addition, as a secondary outcome, meta-analysis results showed a pooled unwillingness rate of 16% (95% CI: 13-20%, I2 = 98.1%, 9 studies).

CONCLUSION

Willingness to vaccinate mpox was high among MSM, but some participants still had negative attitudes towards vaccination. Therefore, the Ministry of Public Health should develop targeted and effective strategies against those influencing factors to prevent and manage mpox outbreaks.

Breakthrough Mpox Outbreak Investigation, the Delicate Balance Between Host Immune Response and Viral Immune Escape

BACKGROUND

Limited data are available on Mpox breakthrough infections.

PURPOSE

The purpose of this study is to investigate a Mpox breakthrough outbreak in 3 vaccinated individuals.

METHODS

Study participants provided informed consent. Serology testing was performed in one involved individual (ID-1) using an in-house assay detecting anti-orthopoxvirus IgG. Whole genome sequencing (WGS) was carried out and compared with the reference sequence ON563414.3 ( https://www.ncbi.nlm.nih.gov/nuccore/ON563414.3/ ).

RESULTS

Three individuals vaccinated with modified vaccinia Ankara-Bavaria Nordic contracted Mpox following one sexual intercourse event. One of them (ID-1) had received only one vaccine dose, while the other two were fully vaccinated. ID-1 presented to the sexual health clinic of the Universitair Ziekenhuis Brussel with proctitis related to Mpox. Despite one vaccination, serology testing Three months post vaccine showed absence of Mpox virus (MPXV) specific antibodies in ID-1. In contrast, 2 weeks after the sexual intercourse, seroconversion occurred. Whole genome sequencing of the isolated MPXV showed, compared with the reference sequence, a total of seven single nucleotide variants with four of them indicating protein amino-acid changes.

CONCLUSION

Incomplete MPXV vaccination as well as MPXV variants might result in breakthrough infections. Preventive measures, such as MPVX vaccination, could maintain immunity in individuals with higher risk of MPXV infection, and might lower disease severity.

Continued circulation of mpox: an epidemiological and phylogenetic assessment, European Region, 2023 to 2024

During the summer of 2023, the European Region experienced a limited resurgence of mpox cases following the substantial outbreak in 2022. This increase was characterised by asynchronous and bimodal increases, with countries experiencing peaks at different times. The demographic profile of cases during the resurgence was largely consistent with those reported previously. All available sequences from the European Region belonged to clade IIb. Sustained efforts are crucial to control and eventually eliminate mpox in the European Region.

Effectiveness and Safety of the MVA-BN Vaccine against Mpox in At-Risk Individuals in the United States (USMVAc)

The mpox 2022 outbreak was declared a public health emergency in July 2022. In August 2022, the MVA-BN vaccine received emergency use authorization in the United States (US) to target at-risk groups. This study (EUPAS104386) used HealthVerity's administrative US healthcare data to generate real-world evidence for MVA-BN vaccine effectiveness and safety to prevent mpox disease in men who have sex with men (MSM) and transgender women, the most affected population during the 2022 mpox outbreak. Fully vaccinated subjects (two doses ≥ 28 days apart) were initially matched with five unvaccinated subjects on calendar date, age, US region, and insurance type. Subjects were followed from index date (14 days after the second dose) until death or data end to ascertain mpox occurrence. After propensity score adjustment, the MVA-BN vaccine effectiveness against mpox disease was 89% (95% CI: 12%, 99%) among those fully vaccinated; attenuated to 64% (95% CI: 40%, 78%) among those with any dose and 70% (95% CI: 44%, 84%) for those with only a single dose. One pericarditis adverse event of special interest was observed when the risk window was extended to 28 days. These results contribute to the totality of evidence supporting the favorable benefit/risk profile of the MVA-BN vaccine.

A global systematic evidence review with meta-analysis of the epidemiological characteristics of the 2022 Mpox outbreaks

BACKGROUND

In 2022, there were outbreaks of Mpox where the disease is not endemic. We summarized published full-text epidemiological data from the outbreaks.

METHODS

A global evidence review (protocol: osf.io/j3kb7) with systematic literature search up to February 09, 2023. We focused on experimental/observational studies of laboratory confirmed Mpox, excluding case reports and case series of < 5 cases. Epidemiological data were pooled using an inverse variance, random-effects model, and pooled estimates presented with associated 95% confidence intervals.

RESULTS

We included 66 studies. Mean incubation period was 7.8 days (6.6-9.0 days, 8 studies: 560 cases), reproductive number 1.8 (1.7-1.9, 6 studies), mean duration from symptom onset to diagnosis 5.8 days (4.8-6.8 days, 4 studies: 982 cases), mean symptom duration 17.5 days (14.7-20.2 days, 3 studies: 292 cases), mean serial interval 8.5 days (7.3-9.9 days, 1 study), hospitalisation 6% (4-9%, 26 studies: 5339 cases), and vaccine effectiveness 78% (65-91%, 3 studies: 953 cases). Highly relevant clinical manifestations were pleomorphic skin lesions 82% (68-94%, 26 studies: 4093 cases), anogenital lesions 64% (51-77%, 9 studies: 10,398 cases), fever 54% (50-57%, 52 studies: 25,992 cases), and lymphadenopathy 51% (46-57%, 42 studies: 17,803 cases), with cases mostly men who have sex with men (MSM). Possibly relevant manifestations were perianal lesions, fatigue, asthenia, myalgia, and headache.

CONCLUSIONS

The 2022 Mpox outbreaks presented with sex-related clinical manifestations and were mostly reported among MSM.

Predicting vaccine effectiveness for mpox

The Modified Vaccinia Ankara vaccine developed by Bavarian Nordic (MVA-BN) was widely deployed to prevent mpox during the 2022 global outbreak. This vaccine was initially approved for mpox based on its reported immunogenicity (from phase I/II trials) and effectiveness in animal models, rather than evidence of clinical efficacy. However, no validated correlate of protection after vaccination has been identified. Here we performed a systematic search and meta-analysis of the available data to test whether vaccinia-binding ELISA endpoint titer is predictive of vaccine effectiveness against mpox. We observe a significant correlation between vaccine effectiveness and vaccinia-binding antibody titers, consistent with the existing assumption that antibody levels may be a correlate of protection. Combining this data with analysis of antibody kinetics after vaccination, we predict the durability of protection after vaccination and the impact of dose spacing. We find that delaying the second dose of MVA-BN vaccination will provide more durable protection and may be optimal in an outbreak with limited vaccine stock. Although further work is required to validate this correlate, this study provides a quantitative evidence-based approach for using antibody measurements to predict the effectiveness of mpox vaccination.

Mpox Diagnosis, Behavioral Risk Modification, and Vaccination Uptake among Gay, Bisexual, and Other Men Who Have Sex with Men, United Kingdom, 2022

During the 2022 multicountry mpox outbreak, the United Kingdom identified cases beginning in May. UK cases increased in June, peaked in July, then rapidly declined after September 2022. Public health responses included community-supported messaging and targeted mpox vaccination among eligible gay, bisexual, and other men who have sex with men (GBMSM). Using data from an online survey of GBMSM during November-December 2022, we examined self-reported mpox diagnoses, behavioral risk modification, and mpox vaccination offer and uptake. Among 1,333 participants, only 35 (2.6%) ever tested mpox-positive, but 707 (53%) reported behavior modification to avoid mpox. Among vaccine-eligible GBMSM, uptake was 69% (95% CI 65%-72%; 601/875) and was 92% (95% CI 89%-94%; 601/655) among those offered vaccine. GBMSM self-identifying as bisexual, reporting lower educational qualifications, or identifying as unemployed were less likely to be vaccinated. Equitable offer and provision of mpox vaccine are needed to minimize the risk for future outbreaks and mpox-related health inequalities.

Safety and Efficacy of the Modified Vaccinia Ankara-Bavaria Nordic Vaccine Against Mpox in the Real World: Systematic Review and Meta-Analysis

In May 2022, mpox began to spread worldwide, posing a serious threat to human public health. Modified Vaccinia Ankara-Bavaria Nordic (MVA-BN) is a live attenuated orthopoxvirus vaccine that has been authorized by the U.S. Food and Drug Administration as the vaccine of choice for the prevention of mpox. In this study, we conducted a meta-analysis of all currently published literature on the efficacy and safety of the MVA-BN vaccine in the real world, showing that the MVA-BN vaccine is effective and safe, with efficacy of up to 75% with a single dose and up to 80% with a two-dose vaccine. Meanwhile, we found that subcutaneous injection has lower local and systemic adverse events than intradermal injection, regardless of single- or two-dose vaccination, and subcutaneous injection is better tolerated in children, the elderly, or people with underlying medical conditions. These results have important reference value for clinical practice.

Factors potentially contributing to the decline of the mpox outbreak in the Netherlands, 2022 and 2023

BackgroundIn 2022 and 2023, a global outbreak of mpox affected mostly gay, bisexual and other men having sex with men (GBMSM). Outbreak control in the Netherlands included isolation, quarantine, post-exposure prophylaxis vaccination and primary preventive vaccination (PPV).AimWe describe the course of the outbreak, the vaccination programme, vaccine effectiveness (VE) of full vaccination against symptomatic disease, and trends in behaviour to generate hypotheses about factors that influenced the outbreak's decline.MethodsIn this observational study, we collected data from public health services on notified cases, number of PPV invitations and PPV doses administered. We calculated PPV uptake and coverage. Trends in behavioural data of GBMSM visiting sexual health centres were analysed for all consultations in 2022. We estimated VE using the screening method.ResultsUntil 31 December 2023, 1,294 mpox cases were reported. The outbreak peaked in early July 2022 and then declined sharply. PPV started on 25 July 2022; in total 29,851 doses were administered, 45.8% received at least one dose, 35.4% were fully vaccinated. The estimated VE was 68.2% (95% CI 4.3-89.5%). We did not observe an evident decrease in high-risk behaviour.DiscussionIt is unlikely that PPV was a driver of the outbreak's decline, as incidence started to decline well before the start of the PPV programme. The possible impact of behavioural change could not be demonstrated with the available indicators, however, the data had limitations, hampering interpretation. We hypothesise that infection-induced immunity in high-risk groups was an important factor explaining the decline.

Safety and immunogenicity of a novel trivalent recombinant MVA-based equine encephalitis virus vaccine: A Phase 1 clinical trial

BACKGROUND

Three encephalitic alphaviruses-western, eastern, and Venezuelan equine encephalitis virus (WEEV, EEEV and VEEV)-can cause severe disease and have the potential to be used as biological weapons. There are no approved vaccines for human use. A novel multivalent MVA-BN-WEV vaccine encodes the envelope surface proteins of the 3 viruses and is thereby potentially able to protect against them all, as previously demonstrated in animal models. This first-in-human study assessed the safety, tolerability, and immunogenicity of MVA-BN-WEV vaccine in healthy adult participants.

METHODS

Forty-five participants were enrolled into 3 dose groups (1 × 10E7 Inf.U, 1 × 10E8 Inf.U, and 2 × 10E8 Inf.U), received 2 doses 4 weeks apart, and were then monitored for 6 months.

RESULTS

The safety profile of MVA-BN-WEV was acceptable at all administered doses, with incidence of local solicited AEs increased with increasing dose and no other clinically meaningful differences between dose groups. One SAE (Grade 2 pleural effusion) was reported in the lowest dose group and assessed as possibly related. No AEs resulted in death or led to withdrawal from the second vaccination or from the trial. The most common local solicited AE was injection site pain, and general solicited AEs were headache, fatigue, and myalgia. MVA-BN-WEV induced humoral immune responses; WEEV-, EEEV- and VEEV-specific neutralizing antibody responses peaked 2 weeks following the second vaccination, and the magnitude of these responses increased with dose escalation. The highest dose resulted in seroconversion of all (100 %) participants for WEEV and VEEV and 92.9 % for EEEV, 2 weeks following second vaccination, and durability was observed for 6 months. MVA-BN-WEV induced cellular immune responses to VEEV E1 and E2 (EEEV and WEEV not tested) and a dose effect for peptide pool E2.

CONCLUSION

The study demonstrated that MVA-BN-WEV is well tolerated, induces immune responses, and is suitable for further development.

CLINICAL TRIAL REGISTRY NUMBER

NCT04131595.

Bisbenzimide compounds inhibit the replication of prototype and pandemic potential poxviruses

We previously identified the bisbenzimide Hoechst 33342 (H42) as a potent multi-stage inhibitor of the prototypic poxvirus, the vaccinia virus (VACV), and several parapoxviruses. A recent report showed that novel bisbenzimide compounds similar in structure to H42 could prevent human cytomegalovirus replication. Here, we assessed whether these compounds could also serve as poxvirus inhibitors. Using virological assays, we show that these bisbenzimide compounds inhibit VACV spread, plaque formation, and the production of infectious progeny VACV with relatively low cell toxicity. Further analysis of the VACV lifecycle indicated that the effective bisbenzimide compounds had little impact on VACV early gene expression but inhibited VACV late gene expression and truncated the formation of VACV replication sites. Additionally, we found that bisbenzimide compounds, including H42, can inhibit both monkeypox and a VACV mutant resistant to the widely used anti-poxvirus drug TPOXX (Tecovirimat). Therefore, the tested bisbenzimide compounds were inhibitors of both prototypic and pandemic potential poxviruses and could be developed for use in situations where anti-poxvirus drug resistance may occur. Additionally, these data suggest that bisbenzimide compounds may serve as broad-activity antiviral compounds, targeting diverse DNA viruses such as poxviruses and betaherpesviruses.IMPORTANCEThe 2022 mpox (monkeypox) outbreak served as a stark reminder that due to the cessation of smallpox vaccination over 40 years ago, most of the human population remains susceptible to poxvirus infection. With only two antivirals approved for the treatment of smallpox infection in humans, the need for additional anti-poxvirus compounds is evident. Having shown that the bisbenzimide H33342 is a potent inhibitor of poxvirus gene expression and DNA replication, here we extend these findings to include a set of novel bisbenzimide compounds that show anti-viral activity against mpox and a drug-resistant prototype poxvirus mutant. These results suggest that further development of bisbenzimides for the treatment of pandemic potential poxviruses is warranted.

Scenarios of future mpox outbreaks among men who have sex with men: a modelling study based on cross-sectional seroprevalence data from the Netherlands, 2022

BackgroundFollowing the 2022-2023 mpox outbreak, crucial knowledge gaps exist regarding orthopoxvirus-specific immunity in risk groups and its impact on future outbreaks.AimWe combined cross-sectional seroprevalence studies in two cities in the Netherlands with mathematical modelling to evaluate scenarios of future mpox outbreaks among men who have sex with men (MSM).MethodsSerum samples were obtained from 1,065 MSM attending Centres for Sexual Health (CSH) in Rotterdam or Amsterdam following the peak of the Dutch mpox outbreak and the introduction of vaccination. For MSM visiting the Rotterdam CSH, sera were linked to epidemiological and vaccination data. An in-house developed ELISA was used to detect vaccinia virus (VACV)-specific IgG. These observations were combined with published data on serial interval and vaccine effectiveness to inform a stochastic transmission model that estimates the risk of future mpox outbreaks.ResultsThe seroprevalence of VACV-specific antibodies was 45.4% and 47.1% in Rotterdam and Amsterdam, respectively. Transmission modelling showed that the impact of risk group vaccination on the original outbreak was likely small. However, assuming different scenarios, the number of mpox cases in a future outbreak would be markedly reduced because of vaccination. Simultaneously, the current level of immunity alone may not prevent future outbreaks. Maintaining a short time-to-diagnosis is a key component of any strategy to prevent new outbreaks.ConclusionOur findings indicate a reduced likelihood of large future mpox outbreaks among MSM in the Netherlands under current conditions, but emphasise the importance of maintaining population immunity, diagnostic capacities and disease awareness.

Human monkeypox virus: Epidemiologic review and research progress in diagnosis and treatment

Monkeypox virus (MPXV) is responsible for causing a zoonotic disease called monkeypox (mpox), which sporadically infects humans in West and Central Africa. It first infected humans in 1970 and, along with the variola virus, belongs to the genus Orthopoxvirus in the poxvirus family. Since the World Health Organization declared the MPXV outbreak a "Public Health Emergency of International Concern" on July 23, 2022, the number of infected patients has increased dramatically. To control this epidemic and address this previously neglected disease, MPXV needs to be better understood and reevaluated. In this review, we cover recent research on MPXV, including its genomic and pathogenic characteristics, transmission, mutations and mechanisms, clinical characteristics, epidemiology, laboratory diagnosis, and treatment measures, as well as prevention of MPXV infection in light of the 2022 and 2023 global outbreaks. The 2022 MPXV outbreak has been primarily associated with close intimate contact, including sexual activity, with most cases diagnosed among men who have sex with men. The incubation period of MPXV infection usually lasts from 6 to 13 days, and symptoms include fever, muscle pains, headache, swollen lymph nodes, and a characteristic painful rash, including several stages, such as macules, papules, blisters, pustules, scabs, and scab shedding involving the genitals and anus. Polymerase chain reaction (PCR) is usually used to detect MPXV in skin lesion material. Treatment includes supportive care, antivirals, and intravenous vaccinia immune globulin. Smallpox vaccines have been designed with four givens emergency approval for use against MPXV infection.

Cardiac glycosides inhibit early and late vaccinia virus protein expression

Cardiac glycosides (CGs) are natural steroid glycosides, which act as inhibitors of the cellular sodium-potassium ATPase pump. Although traditionally considered toxic to human cells, CGs are widely used as drugs for the treatment of cardiovascular-related medical conditions. More recently, CGs have been explored as potential anti-viral drugs and inhibit replication of a range of RNA and DNA viruses. Previously, a compound screen identified CGs that inhibited vaccinia virus (VACV) infection. However, no further investigation of the inhibitory potential of these compounds was performed, nor was there investigation of the stage(s) of the poxvirus lifecycle they impacted. Here, we investigated the anti-poxvirus activity of a broad panel of CGs. We found that all CGs tested were potent inhibitors of VACV replication. Our virological experiments showed that CGs did not impact virus infectivity, binding, or entry. Rather, experiments using recombinant viruses expressing reporter proteins controlled by VACV promoters and arabinoside release assays demonstrated that CGs inhibited early and late VACV protein expression at different concentrations. Lack of virus assembly in the presence of CGs was confirmed using electron microscopy. Thus, we expand our understanding of compounds with anti-poxvirus activity and highlight a yet unrecognized mechanism by which poxvirus replication can be inhibited.

Update on Mpox: What the Primary Care Clinician Should Know

Mpox is a viral infection, which primarily caused sporadic outbreaks in West and Central Africa until causing a global epidemic in 2022. The disease has disproportionately affected people with human immunodeficiency virus and men who have sex with men. Transmission is through close physical contact, including sexual contact. Infection presents with a characteristic rash, with frequent anogenital involvement-polymerase chain reaction of skin lesions is diagnostic. Vaccination is available for primary prevention and postexposure prophylaxis. Treatment consists of supportive care, with antiviral medications available via clinical trials and/or for patients with severe disease.

Mpox Neutralizing Antibody Response to LC16m8 Vaccine in Healthy Adults

BACKGROUND: Vaccination against mpox (formerly known as monkeypox), an infectious disease caused by the monkeypox virus (MPXV), is needed to prevent outbreaks and consequent public health concerns. The LC16m8 vaccine, a dried cell-cultured proliferative live attenuated vaccinia virus–based vaccine, was approved in Japan against smallpox and mpox. However, its immunogenicity and efficacy against MPXV have not been fully assessed. We assessed the safety and immunogenicity of LC16m8 against MPXV in healthy adults. METHODS: We conducted a single-arm study that included 50 participants who were followed up for 168 days postvaccination. The primary end point was the neutralizing antibody seroconversion rate against MPXVs, including the Zr599 and Liberia strains, on day 28. The secondary end points included the vaccine “take” (major cutaneous reaction) rate, neutralizing titer kinetics against MPXV and vaccinia virus (LC16m8) strains, and safety outcomes. RESULTS: Seroconversion rates on day 28 were 72% (36 of 50), 70% (35 of 50), and 88% (44 of 50) against the Zr599 strain, the Liberia strain, and LC16m8, respectively. On day 168, seroconversion rates decreased to 30% (15 of 50) against the Zr599 and Liberia strains and to 76% (38 of 50) against LC16m8. The vaccine “take” (broad definition) rate on day 14 was 94% (46 of 49). Adverse events (AEs), including common solicited cutaneous reactions, occurred in 98% (45 of 48) of participants; grade 3 severity AEs occurred in 16% (8 of 50). No deaths, serious AEs, or mpox onset incidences were observed up to day 168. CONCLUSIONS: The LC16m8 vaccine generated neutralizing antibody responses against MPXV in healthy adults. No serious safety concerns occurred with LC16m8 use. (Funded by the Ministry of Health, Labour and Welfare of Japan; Japan Registry of Clinical Trials number, jRCTs031220171.)

Painful proctitis associated with anorectal mpox, syphilis, HSV, LGV, gonorrhoea and Mycoplasma genitalium in a person living with virologically suppressed HIV and vaccinated against mpox

A gay man with well-controlled HIV and vaccinated against mpox presented with severe proctitis. Testing revealed anorectal mpox, herpes simplex virus, lymphogranuloma venereum, Neisseria gonorrhoeae and Mycoplasma genitalium Serology was indicative of infectious syphilis. This case highlights the need to consider a wide range of concurrent sexually transmitted infections in patients with proctitis, including those vaccinated against mpox.

Single-dose Effectiveness of Mpox Vaccine in Quebec, Canada: Test-negative Design With and Without Adjustment for Self-reported Exposure Risk

INTRODUCTION

During the 2022 mpox outbreak, the province of Quebec, Canada, prioritized first doses for pre-exposure vaccination of people at high mpox risk, delaying second doses due to limited supply. We estimated single-dose mpox vaccine effectiveness (VE) adjusting for virus exposure risk based only on surrogate indicators available within administrative databases (eg, clinical record of sexually transmitted infections) or supplemented by self-reported risk factor information (eg, sexual contacts).

METHODS

We conducted a test-negative case-control study between 19 June and 24 September 2022. Information from administrative databases was supplemented by questionnaire collection of self-reported risk factors specific to the 3-week period before testing. Two study populations were assessed: all within the administrative databases (All-Admin) and the subset completing the questionnaire (Sub-Quest). Logistic regression models adjusted for age, calendar-time and exposure-risk, the latter based on administrative indicators only (All-Admin and Sub-Quest) or with questionnaire supplementation (Sub-Quest).

RESULTS

There were 532 All-Admin participants, of which 199 (37%) belonged to Sub-Quest. With exposure-risk adjustment based only on administrative indicators, single-dose VE estimates were similar among All-Admin and Sub-Quest populations at 35% (95% confidence interval [CI]:-2 to 59) and 30% (95% CI:-38 to 64), respectively. With adjustment supplemented by questionnaire information, the Sub-Quest VE estimate increased to 65% (95% CI:1-87), with overlapping confidence intervals.

CONCLUSIONS

Using only administrative data, we estimate one vaccine dose reduced the mpox risk by about one-third; whereas, additionally adjusting for self-reported risk factor information revealed greater vaccine benefit, with one dose instead estimated to reduce the mpox risk by about two-thirds. Inadequate exposure-risk adjustment may substantially under-estimate mpox VE.

The Current State and Progress of Mpox Vaccine Research

On July 23, 2022, the World Health Organization (WHO) declared the monkeypox (mpox) outbreak a "Public Health Emergency of International Concern." Since 2022, outbreaks of mpox in many countries around the world have primarily resulted in fatalities among immunocompromised individuals, such as untreated HIV/AIDS patients. Since the eradication of smallpox was declared by the WHO in 1980, the global vaccination against smallpox has been gradually discontinued. China also stopped routine smallpox vaccination in 1981. The protective effect of the smallpox vaccine has decreased over time due to aging and declining immunity in those who were vaccinated. For individuals, timely vaccination against smallpox is an effective means of protection against mpox. However, due to safety concerns with the smallpox vaccine and the limitations of current mpox vaccines, there is no vaccine that is safe, effective, and has low side effects applied in clinical settings. This article provides a comprehensive review of the development of mpox virus (MPXV) vaccines, their application in special populations, and the current state of vaccine research, considering the etiology, transmission, and prevention of the MPXV. Vaccination, as an effective method of epidemic prevention, can provide long-term immune protection and effectively reduce the severity of infection. However, as there is no licensed specific MPXV vaccine available globally, the vaccines currently used for mpox prevention are mostly smallpox vaccines. These smallpox vaccines can offer some degree of protection against mpox by activating cross-protection in the body.

Global prediction for mpox epidemic

The mpox epidemic had spread worldwide and become an epidemic of international concern. Before the emergence of targeted vaccines and specific drugs, it is necessary to numerically simulate and predict the epidemic. In order to better understand and grasp its transmission situation, and take some countermeasures accordingly when necessary, we predicted and simulated mpox transmission, vaccination and control scenarios using model developed for COVID-19 predictions. The results show that the prediction model can also achieve good results in predicting the mpox epidemic based on modified SEIR model. The total number of people infected with mpox on Dec 31, 2022 reached 83878, while the prediction of the model was 96456 with a relative error of 15%. The United States, Brazil, Spain, France, the United Kingdom and Germany are six countries with serve mpox epidemic. The predictions of their epidemic are 30543, 11191, 7447, 5945, 5606 and 4291 cases respectively, with an average relative error of 20%. If 30% of the population is vaccinated using a vaccine that is 78% effective, the number of infected people will drop by 29%. This shows that the system can be practically applied to the prediction of mpox epidemic and provide corresponding decision-making reference.

Grasping knowledge, attitude, and perception towards monkeypox among healthcare workers and medical students: an Egyptian cross-sectional study

Background

Monkeypox (Mpox) is a re-emerging infectious disease representing a new global challenge. It poses a substantial threat to countries, particularly those with a low number of cases. Due to its popularity as a tourist destination and its proximity to many African refugees, Egypt is potentially at risk of Mpox importation. Therefore, effective disease management necessitates healthcare workers (HCWs) to possess adept knowledge, along with a positive attitude and behavior. The study aimed to assess the knowledge, attitude, and perception of Egyptian HCWs and medical students towards human Mpox.

Methods

The present cross-sectional study data was collected from participants between October and December 2022 via a questionnaire. The questionnaire comprised 31 questions in the knowledge section, 11 questions in the attitude section, and 14 in the perception section.

Results

The present study involved a total of 1,034 HCWs and medical students. It was found that 55.3% of the participants demonstrated adequate knowledge about Mpox, whereas 44.5% and 39.8% of the respondents exhibited favorable attitudes and perceptions towards the disease, respectively. Binary logistic regression analysis revealed that adequate knowledge was significantly observed in ages older than 40 years (p < 0.001), married participants (p < 0.001), and doctors (p < 0.001). The positive attitude was significantly observed among the male sex (p = 0.045), urban residents (p = 0.002), and nurses (p = 0.002). Conversely, married participants (p = 0.013), doctors (p < 0.001), and individuals employed in pharmacy and laboratory departments (p < 0.001) experienced an increase in positive perception.

Conclusion

Knowledge, attitude, and perception towards Mpox among Egyptian HCWs and medical students exhibit suboptimal levels. Addressing these gaps is crucial to controlling and effectively preventing disease transmission.

Longitudinal Analysis of Mpox Virus DNA Detectability From Multiple Specimen Types During Acute Illness: A Cohort Study

Background

Longitudinal data on the detectability of monkeypox virus (MPXV) genetic material in different specimen types are scarce.

Methods

We describe MPXV-specific polymerase chain reaction (PCR) results from adults with confirmed mpox infection from Toronto, Canada, including a cohort undergoing weekly collection of specimens from multiple anatomic sites until 1 week after skin lesions had fully healed. We quantified the time from symptom onset to resolution of detectable viral DNA (computed tomography [Ct] ≥ 35) by modeling exponential decay in Ct value as a function of illness day for each site, censoring at the time of tecovirimat initiation.

Results

Among 64 men who have sex with men, the median (interquartile range [IQR]) age was 39 (32.75-45.25) years, and 49% had HIV. Twenty received tecovirimat. Viral DNA was detectable (Ct < 35) at baseline in 74% of genital/buttock/perianal skin swabs, 56% of other skin swabs, 44% of rectal swabs, 37% of throat swabs, 27% of urine, 26% of nasopharyngeal swabs, and 8% of semen samples. The median time to resolution of detectable DNA (IQR) was longest for genital/buttock/perianal skin and other skin swabs at 30.0 (23.0-47.9) and 22.4 (16.6-29.4) days, respectively, and shortest for nasopharyngeal swabs and semen at 0 (0-12.1) and 0 (0-0) days, respectively. We did not observe an effect of tecovirimat on the rate of decay in viral DNA detectability in any specimen type (all P > .05).

Conclusions

MPXV DNA detectability varies by specimen type and persists for over 3-4 weeks in skin specimens. The rate of decay did not differ by tecovirimat use in this nonrandomized study.

Immunogenicity and reactogenicity of modified vaccinia Ankara pre-exposure vaccination against mpox according to previous smallpox vaccine exposure and HIV infection: prospective cohort study

Background

Pre-exposure vaccination with MVA-BN has been widely used against mpox to contain the 2022 outbreak. Many countries have defined prioritized strategies, administering a single dose to those historically vaccinated for smallpox, to achieve quickly adequate coverage in front of low supplies. Using epidemiological models, real-life effectiveness was estimated at approximately 36%-86%, but no clinical trials were performed. Few data on MVA-BN immunogenicity are currently available, and there are no established correlates of protection. Immunological response in PLWH in the context of the 2022 outbreak was also poorly described.

Methods

Blood samples were collected from participants eligible for pre-exposure MVA-BN vaccination before (T1) receiving a full course of vaccine (single-dose for vaccine-experienced or smallpox-primed and two-dose for smallpox vaccine-naïve or smallpox non-primed) and one month after the last dose (T2 and T3, respectively). MPXV-specific IgGs were measured by in-house immunofluorescence assay, using 1:20 as screening dilution, MPXV-specific nAbs by 50% plaque reduction neutralization test (PRNT50, starting dilution 1:10), and IFN-γ-producing specific T cells to MVA-BN vaccine, by ELISpot assay. Paired or unpaired t-test and Wilcoxon or Mann-Whitney test were used to analyse IgG and nAbs, and T-cell response, as appropriate. The probability of IgG and nAb response in vaccine-experienced vs. vaccine-naïve was estimated in participants not reactive at T1. The McNemar test was used to evaluate vaccination's effect on humoral response both overall and by smallpox vaccination history. In participants who were not reactive at T1, the proportion of becoming responders one month after full-cycle completion by exposure groups was compared by logistic regression and then analysed by HIV status strata (interaction test). The response was also examined in continuous, and the Average Treatment Effect (ATE) of the difference from baseline to schedule completion according to previous smallpox vaccination was estimated after weighting for HIV using a linear regression model. Self-reports of adverse effects following immunization (AEFIs) were prospectively collected after the first MVA-BN dose (T1). Systemic (S-AEFIs: fatigue, myalgia, headache, GI effects, chills) and local (L-AEFIs: redness, swelling, pain) AEFIs were graded as absent (grade 0), mild (1), moderate (2), or severe (3). The maximum level of severity for S-AEFIs and L-AEFIs ever experienced over the 30 days post-dose by vaccination exposure groups were analysed using a univariable multinomial logistic regression model and after adjusting for HIV status; for each of the symptoms, we also compared the mean duration by exposure group using an unpaired t-test.

Findings

Among the 164 participants included, 90 (54.8%) were smallpox vaccine-experienced. Median age was 49 years (IQR 41-55). Among the 76 (46%) PLWH, 76% had a CD4 count >500 cells/μL. There was evidence that both the IgG and nAbs titers increased after administration of the MVA-BN vaccine. However, there was no evidence for a difference in the potential mean change in humoral response from baseline to the completion of a full cycle when comparing primed vs. non-primed participants. Similarly, there was no evidence for a difference in the seroconversion rate after full cycle vaccination in the subset of participants not reactive for nAbs at T1 (p = 1.00 by Fisher's exact test). In this same analysis and for the nAbs outcome, there was some evidence of negative effect modification by HIV (interaction p-value = 0.17) as primed people living with HIV (PLWH) showed a lower probability of seroconversion vs. non-primed, and the opposite was seen in PLWoH. When evaluating the response in continuous, we observed an increase in T-cell response after MVA-BN vaccination in both primed and non-primed. There was evidence for a larger increase when using the 2-dose vs. one-dose strategy with a mean difference of -2.01 log2 (p ≤ 0.0001), after controlling for HIV. No evidence for a difference in the risk of developing any AEFIs of any grade were observed by exposure group, except for the lower risk of grade 2 (moderate) fatigue, induration and local pain which was lower in primed vs. non-primed [OR 0.26 (0.08-0.92), p = 0.037; OR 0.30 (0.10-0.88), p = 0.029 and OR 0.19 (0.05-0.73), p = 0.015, respectively]. No evidence for a difference in symptom duration was also detected between the groups.

Interpretation

The evaluation of the humoral and cellular response one month after the completion of the vaccination cycle suggested that MVA-BN is immunogenic and that the administration of a two-dose schedule is preferable regardless of the previous smallpox vaccination history, especially in PLWH, to maximize nAbs response. MVA-BN was safe as well tolerated, with grade 2 reactogenicity higher after the first administration in vaccine-naïve than in vaccine-experienced individuals, but with no evidence for a difference in the duration of these adverse effects. Further studies are needed to evaluate the long-term duration of immunity and to establish specific correlates of protection.

Funding

The study was supported by the National Institute for Infectious Disease Lazzaro Spallanzani IRCCS "Advanced grant 5 × 1000, 2021" and by the Italian Ministry of Health "Ricerca Corrente Linea 2".

Human mpox: global trends, molecular epidemiology and options for vaccination

The eradication of smallpox and the cessation of vaccination have led to the growth of the susceptible human population to poxviruses. This has led to the increasing detection of zoonotic orthopoxviruses. Among those viruses, monkeypox virus (MPV) is the most commonly detected in Western and Central African regions. Since 2022, MPV is causing local transmission in newly affected countries all over the world. While the virus causing the current outbreak remains part of clade II (historically referred to as West African clade), it has a significant number of mutations as compared to other clade II sequences and is therefore referred to as clade IIb. It remains unclear whether those mutations may have caused a change in the virus phenotype. Vaccine effectiveness data show evidence of a high cross-protection of vaccines designed to prevent smallpox against mpox. These vaccines therefore represent a great opportunity to control human-to-human transmission, provided that their availability has short time-frames and that mistakes from the recent past (vaccine inequity) will not be reiterated.

What determines mpox vaccination uptake? Assessing the effect of intent-to-vaccinate versus other determinants among men who have sex with men

BACKGROUND

In response to the mpox outbreak, vaccination was offered in the Netherlands to men who have sex with men (MSM) at increased risk for mpox. Successful vaccination campaigns are leveraged by high intent-to-vaccinate, yet intent might not always lead to uptake. Therefore, we assessed the impact of intent-to-vaccinate and other factors on vaccination uptake among participants of the Amsterdam Cohort Studies (ACS).

METHOD

In July 2022, prior to the mpox vaccination campaign, we distributed an online survey regarding mpox intent-to-vaccinate, as well as e.g. beliefs, attitude, subjective norms, and perception of risk among ACS participants (all MSM). Vaccination uptake was self-reported during study visits after August 2022. The association between vaccination intent and uptake, and determinants of intent, was jointly assessed using a structural equation model (SEM) based on components of the Theory of Planned Behavior (TPB). In a second SEM, determinants of intent were allowed to have a direct effect on vaccination uptake.

RESULTS

492 MSM (median age = 46 years) were included in analyses. 380 (77%) had high intent-to-vaccinate and 238 (48%) received at least one vaccine dose. In the first model with a direct relation between intent and uptake only, TBP components predicted intent as expected, and high intent-to-vaccinate was significantly associated with getting vaccinated (β = 1.1, 95%CI = 0.6-1.5). However, 175/380 (46%) participants with high intent-to-vaccinate did not get vaccinated. The second model had an improved model fit compared to the first model. The effect of intent on uptake was non-significant, and only perceiving to be at higher risk of infection significantly increased vaccination uptake later on (β = 0.42, 95%CI = 0.26-0.59). Having a steady relationship decreased the probability of vaccination (β = -0.59, 95%CI = -1.0- -0.18).

CONCLUSIONS

While intent-to-vaccinate for mpox was high among MSM, high intent did not necessarily result in vaccine uptake. Mpox risk perception might have played a more pivotal role in getting vaccinated, which may be related to the evolution of vaccination eligibility criteria and accessibility to the vaccine.

Transmission dynamics and effect of control measures on the 2022 outbreak of mpox among gay, bisexual, and other men who have sex with men in England: a mathematical modelling study

BACKGROUND

The 2022 global outbreak of mpox (formerly known as monkeypox) spread primarily among gay, bisexual, and other men who have sex with men (GBMSM), with the initial cluster being identified in England in May, 2022. Understanding its epidemiological characteristics and the reasons for its downturn in July, 2022, will help to control future outbreaks.

METHODS

We collated data for all diagnosed mpox cases (3621) from England from May 1, 2022, to Nov 16, 2022. Data from 75 individuals with mpox allowed estimation of the incubation period, while data from 121 case-contact pairs were used to estimate the serial interval. Six methods, including a structured dynamic compartmental transmission model, were used to estimate the basic reproduction number (R0). The structured model assumed all male individuals with mpox were GBMSM, who were then stratified into subgroups for those at low risk and high risk for mpox. This best fitting model was used to estimate the reduction in transmissibility, and the effective infectious period (before isolating), that resulted in the outbreak downturn, and the effect of vaccination initiated from June 27, 2022. Bayesian methods were used for parameter estimation and model calibration.

FINDINGS

Most cases occurred in men (3544 of 3621, 97·9%). The median incubation period for mpox was 6·90 days (95% credible interval [CrI] 4·08-20·21), and the serial interval was 8·82 days (5·22-25·81). R0 estimates ranged from 1·41 to 2·17. The structured transmission model estimated that 83·8% of infections (95% CrI 83·5-85·3) resulted from sexual partnerships with GBMSM individuals at high risk of mpox. The outbreak downturn probably resulted from a 44·5% reduction in the sexual partner rate among all GBMSM (24·9-55·8) and 20·0% reduction in the effective infectious period (4·1-33·9), preventing 165 896 infections (115 584-217 730). Vaccination marginally increased the number of infections prevented (166 081, 115 745-217 947), but minimised a resurgence in cases from January, 2023, and could have averted four times more infections if initiated earlier. Our findings were sensitive to assumptions regarding the vaccine's effectiveness and the GBMSM subgroup at high risk of mpox.

INTERPRETATION

The mpox outbreak in England probably resulted from high sexual partner rates among some GBMSM, with reductions in partner rates reversing the outbreak, and with vaccination minimising future outbreaks.

FUNDING

National Institute for Health Research (UK).

Human Monkeypox Virus and Host Immunity: New Challenges in Diagnostics and Treatment Strategies

The monkeypox virus (MPXV), responsible for human disease, has historically been limited to the African countries, with only a few isolated instances reported elsewhere in the world. Nevertheless, in recent years, there have been occurrences of monkeypox in regions where the disease is typically absent, which has garnered global interest. Within a period of less than four months, the incidence of MPXV infections has surged to over 48,000 cases, resulting in a total of 13 deaths. This chapter has addressed the genetics of the pox virus, specifically the human monkeypox virus, and its interaction with the immune systems of host organisms. The present chapter is skillfully constructed, encompassing diagnostic methodologies that span from traditional to developing molecular techniques. Furthermore, the chapter provides a succinct analysis of the therapeutic methods employed, potential future developments, and the various emerging difficulties encountered in illness management.

Vaccines against mpox: MVA-BN and LC16m8

INTRODUCTION

Global outbreaks involving mpox clade IIb began in mid-2022. Today, clade IIb and clade I outbreaks continue. Reliable mpox vaccines can prevent serious mpox disease and death.

AREAS COVERED

Globally, two vaccines hold mpox indications, regardless of mpox viral clade: MVA-BN (Bavarian Nordic) and LC16m8 (KM Biologics). This review summarizes the human and pivotal animal data establishing safety and efficacy for MVA-BN and LC16m8, including real-world evidence gathered during mpox outbreaks from 2022 through 2024.

EXPERT OPINION

Some regulatory decisions for MVA-BN and LC16m8 followed pathways based on surrogate outcomes, including lethal-challenge studies in nonhuman primates, among other atypical aspects. Nonetheless, MVA-BN and LC16m8 hold unencumbered registration in multiple countries. Effectiveness of MVA-BN as primary preventive vaccination (PPV) in humans against clade IIb mpox is clear from real-world studies; effectiveness of LC16m8 against clade IIb is likely from surrogate endpoints. Effectiveness of MVA-BN and LC16m8 as PPV against more-lethal clade I is likely, based on animal-challenge studies with multiple orthopoxvirus species and other studies. Both vaccines have solid safety records. MVA-BN's replication incompetence favors adoption, whereas LC16m8 has more pediatric data. Additional real-world evidence, in additional geographic settings and special populations (e.g. pregnancy, immune suppression, atopic dermatitis), is needed.

[Human monkeypox (Mpox)]

Until recently, human monkeypox (Mpox) were rarely observed outside of Africa, where the Mpox virus (MPXV) is endemic in some regions. In early May 2022, a global Mpox outbreak occurred. Crucial to this outbreak was human-to-human transmission during sexual activity. In particular, young men who have sex with men (MSM) became ill. In July 2022, this Mpox epidemic was declared a public health emergency of international concern by the World Health Organization. As of 26 September 2023, 90,618 confirmed cases of Mpox have been reported worldwide, with Germany accounting for around 3700 cases. The strongest increase in incidence occurred from May to mid-August 2022; since then, the number of cases has declined significantly as a result of intensive prevention efforts (education, vaccination). Currently, there are only sporadic, smaller outbreaks-in Germany (Berlin) most recently in August 2023. Despite the current calm epidemiological situation worldwide, isolated cases must therefore still be expected in Germany. The clinical picture of the "new" clade IIb-associated Mpox variant, which is mostly transmitted sexually from person to person, differs markedly from that of the "classical" Mpox (clades I and IIa), which, apart from rapidly breaking human infection chains, essentially occur as a zoonosis.

Plausible reasons for the resurgence of Mpox (formerly Monkeypox): an overview

Poxviruses are large and diversified viruses that cause an emerging zoonotic disease known as monkeypox (mpox). In the past, mpox predominated primarily in the rural rainforests of Central and West Africa. Recently, the exportation of mpoxv from Africa to other continents has been progressively reported. However, the lack of travel history to Africa in most of the currently reported cases in 2022 promotes the sign of changing epidemiology of this disease. Concerns over the geographic distribution and continued resurgence of mpox is growing. In this review, we addressed the geographic distribution, transmission, reasons for the resurgence of mpox, and vaccination. Although the precise cause of the resurgence in mpox cases is mostly unknown, several suggested factors are believed to be waning immunity, accumulation of unvaccinated people, ecological conditions, risk behaviors of men who have sex with men, and genetic evolution.

Viral blips and virologic failures following mpox vaccination with MVA-BN among people with HIV

OBJECTIVES

The study aim was to evaluate whether mpox vaccination with modified vaccinia Ankara-Bavarian Nordic (MVA-BN) may be associated with viral blips or confirmed virologic failures (CVF) in people with HIV (PWH) receiving antiretroviral therapy and the associated factors.

DESIGN

PWH who received MVA-BN, with HIV-RNA less than 50 copies/ml, and CD4 + lymphocytes at least 200 cells/μl in the 6 months prior to vaccination and at least 1 HIV-RNA determination within 3 months from vaccination.

METHODS

The primary outcome was occurrence of viral blips (1 HIV-RNA ≥50 copies/ml) and CVF (1 HIV-RNA ≥1000 copies/ml or ≥2 consecutive HIV-RNA ≥50 copies/ml) following MVA-BN. Changes in CD4 + and CD4 + /CD8 + were secondary outcomes. Residual viremia was defined as detectable HIV-RNA less than 50 copies/ml. PWH already vaccinated against smallpox received single-dose MVA-BN. Mann--Whitney rank-sum test or chi-square/Fisher's test applied.

RESULTS

Overall, 187 PWH were included: 147 received two doses of MVA-BN, 40 single-dose. Six viral blips [incidence rate = 1.59/100-person months of follow-up (PMFU), 95% confidence interval (95% CI) = 0.58-3.47], and three CVFs [incidence rate = 0.80/100-PMFU (95% CI = 0.16-2.33)] were observed. Two CVFs occurred at second dose with presence of detectable HIV-RNA following first one, with high compliance to antiretroviral therapy (ART). PWH with viral blips or CVFs had, prior to first vaccination, more frequently residual viremia [77% ( n  = 7) versus 35% ( n  = 62), P  = 0.01]. No differences in ART ( P  = 0.42) and number of MBA-BN doses ( P  = 0.40) was found. In two cases of CVFs, ART was changed; all VBs resolved within 1 month.

CONCLUSION

Although rare, viral blips and CVFs following MVA-BN vaccination among PWH receiving ART were identified. Close monitoring of HIV-RNA during mpox vaccination should be encouraged.