Reduced Risk for Mpox After Receipt of 1 or 2 Doses of JYNNEOS Vaccine Compared with Risk Among Unvaccinated Persons - 43 U.S. Jurisdictions, July 31-October 1, 2022

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.

Comparison of protection against mpox following mRNA or modified vaccinia Ankara vaccination in nonhuman primates

In 2022, mpox virus (MPXV) spread worldwide, causing 99,581 mpox cases in 121 countries. Modified vaccinia Ankara (MVA) vaccine use reduced disease in at-risk populations but failed to deliver complete protection. Lag in manufacturing and distribution of MVA resulted in additional MPXV spread, with 12,000 reported cases in 2023 and an additional outbreak in Central Africa of clade I virus. These outbreaks highlight the threat of zoonotic spillover by Orthopoxviruses. mRNA-1769, an mRNA-lipid nanoparticle (LNP) vaccine expressing MPXV surface proteins, was tested in a lethal MPXV primate model. Similar to MVA, mRNA-1769 conferred protection against challenge and further mitigated symptoms and disease duration. Antibody profiling revealed a collaborative role between neutralizing and Fc-functional extracellular virion (EV)-specific antibodies in viral restriction and ospinophagocytic and cytotoxic antibody functions in protection against lesions. mRNA-1769 enhanced viral control and disease attenuation compared with MVA, highlighting the potential for mRNA vaccines to mitigate future pandemic threats.

Prospective observational study on scar sequelae after MPOX infection: an analysis of 40 patients

BACKGROUND

Monkeypox (MPOX) caused a public health emergency of international concern (PHEIC) outbreak between 2022 and 2023, with a recent rise in cases that prompted the World Health Organization (WHO) to declare the disease a PHEIC once again. There is little information on its long-term scarring sequelae.

OBJECTIVES

The objective of this study was to assess the risk and characteristics of scarring in patients with MPOX in a tertiary hospital.

METHODS

This is a prospective cohort study including patients diagnosed using polymerase chain reaction (PCR) tests. Clinical data were collected and followed up at 12-15 months to assess scarring and its impact on quality of life.

RESULTS

Of the 40 patients, 19 (47.5%) developed scars, which were more common in those with initial cutaneous manifestations. Scars significantly affected the quality of life, especially in the genital and mucosal areas. The limited sample and loss to follow-up may affect the validity of the results.

CONCLUSION

Scarring is a frequent and disfiguring sequela of MPOX, particularly in patients with early skin symptoms. Prevention and close follow-up are crucial in mitigating these complications.

Impact of vaccination with third generation modified vaccinia Ankara and sexual behaviour on mpox incidence in men who have sex with men: analysis among participants of the ANRS-174 DOXYVAC trial

Background

Mpox was first reported in France on May 19 and third-generation live Modified Vaccinia Ankara (MVA-BN) vaccination of multiple-partner men who have sex with men (MSM) was recommended as of July 11, 2022. We assessed the impact of vaccination and of sexual behavior adopted during the epidemic period on mpox incidence in the ANRS-174-DOXYVAC trial enrolling MSM on HIV pre-exposure prophylaxis (PrEP) with history of sexually-transmitted infections (STI) in the previous year.

Methods

We compared pre-epidemic socio-behavioral characteristics and change in sexual behaviors after the onset of the epidemic of participants with mpox and mpox-free. Then we compared incidence rates of mpox per 1000 person-months (p-m) between May 9-July 10 (before vaccination of MSM, period-1) and July 11-September 20 2022 (after vaccination launch, period-2) and explored factors explaining the period effect using Poisson regression model.

Findings

472 MSM had data before and after May 9, 2022. Twenty percent had received smallpox vaccine during childhood. Mpox occurred in 77/472 participants (incidence 49.3 per 1000 p-m (95% CI 38.9-61.6)). MVA-BN vaccination roll-out was rapid, with 86% (341/398) of eligible participants having received at least one dose by September 20, 2022. Sexual behavior significantly changed before and after May 9, with a decrease in the proportion of mpox-free participants with >10 partners during last 3 months (45% vs 38%, p = 0.0035). Mpox incidence was 67.4 per 1000 p-m (95% CI 51.6-86.6) in period-1, and 24.4 per 1000 p-m (95% CI 13.9-39.6) in period-2, with an incidence rate ratio of 0.36 (95% CI 0.21-0.63). In multivariable Poisson regression model, only MVA-BN vaccination in 2022 remained significantly associated with mpox incidence, with a 99% risk reduction (95% CI 96.6-99.7).

Interpretation

In MSM on PrEP enrolled in the ANRS-174-DOXYVAC trial, rapid roll-out of MVA-BN vaccination was associated with a strong reduction in mpox incidence.

Funding

ANRS Maladies Infectieuses Emergentes (ANRS/MIE).

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.

Development and validation of the mpox stigma scale (MSS) and mpox knowledge scale (MKS)

BACKGROUND

Few validated brief scales are available to measure constructs that may hinder mpox-related prevention and care engagement, such as knowledge and stigma. Both are highly salient barriers to infectious disease care and disease understanding, precursors to evaluating one's risk and need to, for example, accept vaccination. To address this gap, we developed and validated the Mpox Stigma Scale (MSS) and Mpox Knowledge Scale (MKS).

METHODS

As part of a full-scale clinical trial, we offered an optional mpox survey to participants who self-identified as African American or Black, were 18-29 years old, and lived in Alabama, Georgia, or North Carolina (2023, N = 330). We calculated psychometric properties through confirmatory factor analyses (CFA) and applied Comparative Fit Index (CFI), Goodness of Fit Index (GFI), and Tucker-Lewis Index (TLI) values equal to or exceeding 0.90 and Root Mean Square Error of Approximation (RMSEA) and Standardized Root Mean Square Residual (SRMR) values less than 0.08 to determine adequate model fit. We computed internal reliability using Cronbach's alpha and calculated Pearson or Spearman correlation coefficients between the MSS and MKS and related variables.

RESULTS

For the MSS, CFA results showed that the one-factor model fit the data well (χ2(df = 5, N = 330) = 34.962, CFI = 0.97, GFI = 0.99, TLI = 0.94, RMSEA = 0.13, SRMR = 0.03). For the MKS, the one-factor model provided a good fit to the data (χ2(df = 6, N = 330) = 8.44, CFI = 0.99, GFI = 0.99, TLI = 0.95, RMSEA = 0.15, SRMR = 0.02). Cronbach's alphas were MSS = 0.91 and MKS = 0.83, suggesting good to excellent reliability. The MSS was correlated with the MKS (r = .55, p < .001), stigmatizing attitudes (r = .24, p < .001), attitudes towards mpox vaccination (r=-.12, p = .030), and worry about contracting mpox (r = .44, p < .001). The MKS was correlated with worry about contracting mpox (r = .30, p < .001) and mpox disclosure (r=-.16, p = .003).

CONCLUSIONS

The MSS and MKS are reliable and valid tools for public health practice, treatment and prevention research, and behavioral science. Further validation is warranted across populations and geographic locations.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05490329.

Discordant performance of mpox serological assays

BACKGROUND

Since July 23, 2022, global mpox cases reached 92,546, with over 31,000 in the United States. Asymptomatic carriage is a critical mechanism influencing the global dissemination of mpox. Seroprevalence studies are crucial for determining the epidemic's true burden, but uncertainties persist in serologic assay performance and how smallpox vaccination may influence assay interpretation.

OBJECTIVES

Our study aimed to assess the performance of several diagnostic assays among mpox-positive, vaccinated, and pre-outbreak negative control samples. This investigation sought to enhance our understanding and management of future mpox outbreaks.

STUDY DESIGN

Serum samples from 10 mpox-positive, five vaccinated uninfected, and 137 pre-outbreak controls were obtained for serological testing. The mpox-positive samples were obtained around 100 days post symptom onset, and vaccinated patients were sampled approximately 90 days post-vaccination. Multiple diagnostic assays were employed, including four commercial ELISAs (Abbexa, RayBioTech, FineTest, ProteoGenix) and a multiplex assay (MesoScale Diagnostics (MSD)) measuring five mpox and five smallpox antigens.

RESULTS

Three commercial ELISA kits had low specificity (<50 %). The Proteogenix ELISA targeting the E8L antigen had a 94 % sensitivity and 87 % specificity. The E8L antigen on the MSD assay exhibited the greatest distinction between exposure groups, with 98 % sensitivity and 93 % specificity.

CONCLUSIONS

None of the assays could distinguish between mpox-positive and vaccinated samples. The MSD assay targeting the MPXV E8L antigen demonstrated the greatest differentiation between mpox-positive and pre-outbreak negative samples. Our findings underscore the imperative to identify sensitive and specific assays to monitor population-level mpox exposure and 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.

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.

Serologic responses to the MVA-based JYNNEOS mpox vaccine in a cohort of participants from the District of Columbia (D.C.)

We assessed early antibody responses after two doses of JYNNEOS (IMVANEX) mpox vaccine in the District of Columbia (D.C.) in persons at high risk for mpox without characteristic lesions or rash. Participants with PCR mpox negative specimens (oral swab, blood, and/or rectal swab) on the day of receipt of the first vaccine dose and who provided a baseline (day 0) serum sample and at least one serum sample at ∼28, ∼42-56 days, or 180 days post vaccination were included in this analysis. Orthopoxvirus (OPXV)-specific IgG and IgM ELISAs and neutralizing antibody titers were performed, and longitudinal serologic responses were examined. Based on participants' IgG and IgM antibody levels at baseline, they were categorized as naïve or non-naïve. Linear mixed effects regression models were conducted to determine if IgG antibody response over time varied by age, sex, HIV status, and route of administration for both naïve and non-naïve participants. Among both naïve and non-naïve participants IgG seropositivity rates increased until day 42-56, with 89.4 % of naïve and 92.1 % of non-naïve participants having detectable IgG antibodies. The proportion of naive participants with detectable IgG antibodies declined by day 180 (67.7 %) but remained high among non-naïve participants (94.4 %). Neutralizing antibody titers displayed a similar pattern, increasing initially post vaccination but declining by day 180 among naïve participants. There were no significant serologic response differences by age, sex, or HIV status. Serologic response did vary by route of vaccine administration, with those receiving a combination of intradermal and subcutaneous doses displaying significantly higher IgG values than those receiving both doses intradermally. These analyses provide initial insights into the immunogenicity of a two-dose JYNNEOS PEP regimen in individuals at high risk of mpox exposure in the United States.

Global prevalence and correlates of mpox vaccine acceptance and uptake: a systematic review and meta-analysis

BACKGROUND

Vaccination has been recommended as one of the most potent ways of controlling the mpox (formerly, monkeypox) outbreak, particularly among high-risk groups. Here, we evaluated the prevalence of mpox vaccine acceptance and uptake globally.

METHODS

We searched multiple databases for peer-reviewed studies published in English from May 2022 to 25th November 2023 that evaluated mpox vaccine acceptance and/or uptake. We fit a random-effects model meta-analysis to calculate the pooled mpox vaccine acceptance and uptake rates, with their 95% confidence intervals (CI) across population outcomes. We performed subgroup analyses among the six World Health Organization (WHO) regions (Africa [AFR], Region of the Americas [AMR], South-East Asia Region [SEAR], European Region [EUR], Eastern Mediterranean Region [EMR], and the Western Pacific Region [WPR]), as well as among select population subgroups.

RESULTS

Of the 2531 studies screened, 61 studies, with a cumulative sample size of 263,857 participants from 87 countries were eligible for inclusion. The overall vaccine acceptance and uptake rates were 59.7% and 30.9% globally. Acceptance and uptake rates among the LGBTQI+ community were 73.6% vs 39.8% globally, 60.9% vs. 37.1% in AMR, 80.9% vs. 50.0% in EUR, and 75.2% vs. 33.5% in WPR. Among PLHIV, vaccine acceptance and uptake rates were 66.4% vs. 35.7% globally, 64.0% vs. 33.9% in AMR, 65.1% vs. 27.0% in EUR, and 69.5% vs. 46.6% in WPR. Among healthcare workers, vaccination intention was 51.0% globally.

CONCLUSIONS

Tailored interventions are needed to bolster confidence in the mpox vaccine, maximize vaccine uptake, and increase vaccine access to close the gaps between acceptance and uptake especially among key populations residing in regions with low rates of acceptance and uptake.

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.

Pivoting COVID-19 Resources for an Equitable Mpox Vaccine Response in Louisiana

Introduction

The first case of mpox in Louisiana was identified 2 months ahead of Southern Decadence Festival in New Orleans, the largest LGBTQ+ Pride festival in the South. With mpox case numbers reflecting racial disparities, the objective was to mount an equitable vaccination response.

Methods

The Louisiana Department of Health rapidly pivoted its COVID-19 resources and strategies-specifically, using vaccine strike teams and mobile events, in-state vaccine redistribution through centralized warehousing and shipping support, and community partnerships-to now control mpox transmission. Here, the authors have evaluated state-based Immunization Information System data to examine whether the vaccination response was geographically and racially equitable. Geographic equity was measured by taking into account vaccine availability as well as uptake in areas with high Social Vulnerability Index.

Results

A total of 113 providers were enrolled in the vaccination program, and 96 mobile vaccination events were held in locations frequented by at-risk populations. Racial disparities among vaccine recipients decreased over time, and vaccine availability and uptake were equitable in areas with high Social Vulnerability Indices. However, Black, female, and Hispanic/Latinx patients had significantly higher risk of not completing the 2-dose series than their counterparts.

Conclusions

The mpox vaccination response in Louisiana was geographically equitable, though some demographic disparities remained.

Serological Evidence of Mpox Virus Infection During Peak Mpox Transmission in New York City, July to August 2022

BACKGROUND

The extent to which infections may have been undetected in an epicenter of the 2022 mpox outbreak is unknown.

METHODS

A serosurvey (July and August 2022) assessed the seroprevalence and correlates of mpox infection among a diverse sample of asymptomatic patients with no prior mpox diagnoses and no known histories of smallpox or mpox vaccination. We present seropositivity stratified by participant characteristics collected via survey.

RESULTS

Two-thirds of 419 participants were cismen (281 of 419), of whom 59.1% (166 of 281) reported sex with men (MSM). The sample also included 109 ciswomen and 28 transgender/gender nonconforming/nonbinary individuals. Overall seroprevalence was 6.4% (95% confidence interval [CI], 4.1%-8.8%); 3.7% among ciswomen (95% CI, 1.0%-9.1%), 7.0% among cismen with only ciswomen partners (95% CI, 2.0%-11.9%), and 7.8% among MSM (95% CI, 3.7%-11.9%). There was little variation in seroprevalence by race/ethnicity, age group, HIV status, or number of recent sex partners. No participants who reported close contact with mpox cases were seropositive. Among participants without recent mpox-like symptoms, 6.3% were seropositive (95% CI, 3.6%-9.0%).

CONCLUSIONS

Approximately 1 in 15 vaccine-naive people in our study had antibodies to mpox during the height of the NYC outbreak, indicating the presence of asymptomatic infections that could contribute to ongoing transmission.

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.

Addressing mpox at a Frontline Community Health Center: Lessons for the Next Outbreak

The 2022 mpox (formerly monkeypox) outbreak affected predominantly men who have sex with men (MSM), likely through sexual transmission, which resulted in institutions specializing in sexual health being at the frontlines of the mpox outbreak. Fenway Health in Boston serves close to 10 000 MSM annually, which includes more than 2400 MSM who are living with HIV and 3320 MSM with active HIV preexposure prophylaxis (PrEP) prescriptions. We report on the programs implemented and changes to clinical practice at Fenway Health during the mpox outbreak. Fenway Health diagnosed its first case of mpox in June 2022 and treated this patient with tecovirimat. In early July 2022, Fenway Health administered its first dose of the Jynneos vaccine under the Emergency Use Authorization for protection against mpox. As of October 6, 2022, 69 people had tested positive for the mpox virus at Fenway Health. Among the 69 people who tested positive, 43 (62.3%) self-identified as male, with the remaining not reporting a sex or gender identity, and 40 (58.0%) reported their sexual orientation as gay or bisexual. Twenty-five people (36.2%) were treated with tecovirimat. As of October 30, 2022, Fenway Health had administered 6376 doses of the Jynneos vaccine. The programmatic changes involved in rollout and scale-up of vaccination, treatment, and community outreach services at Fenway Health during the 2022 mpox outbreak that we describe here could inform strategies to address subsequent outbreaks.

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.

Mpox vaccination and treatment: a systematic review

The Human monkeypox virus (mpox) belongs to the Poxviridae family, characterized by double-stranded DNA. A 2022 outbreak, notably prevalent among men who have sex with men, was confirmed by the World Health Organization. To understand shifting prevalence patterns and clinical manifestations, we conducted a systematic review of recent animal and human studies. We comprehensively searched PubMed, Scopus, Web of Science, Cochrane Library, and Clinicaltrials.gov, reviewing 69 relevant articles from 4,342 screened records. Our analysis highlights Modified Vaccinia Ankara - Bavarian Nordic (MVA-BN)'s potential, though efficacy concerns exist. Tecovirimat emerged as a prominent antiviral in the recent outbreak. However, limited evidence underscores the imperative for further clinical trials in understanding and managing monkeypox.

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.

Intriguing insight into unanswered questions about Mpox: exploring health policy implications and considerations

The 2022 multi-country Monkeypox (Mpox) outbreak has added concerns to scientific research. However, unanswered questions about the disease remain. These unanswered questions lie in different aspects, such as transmission, the affected community, clinical presentations, infection and prevention control and treatment and vaccination. It is imperative to address these issues to stop the spread and transmission of disease. We documented unanswered questions with Mpox and offered suggestions that could help put health policy into practice. One of those questions is why gay, bisexual or other men who have sex with men (gbMSM) are the most affected community, underscoring the importance of prioritizing this community regarding treatment, vaccination and post-exposure prophylaxis. In addition, destigmatizing gbMSM and implementing community-based gbMSM consultation and action alongside ethical surveillance can facilitate other preventive measures such as ring vaccination to curb disease transmission and track vaccine efficacy. Relevant to that, vaccine and drug side effects have implied the questionability of their use and stimulated the importance of health policy development regarding expanded access and off-label use, expressing the need for safe drug and vaccine development manufacturing. The possibility of reverse zoonotic has also been raised, thus indicating the requirement to screen not only humans, but also their related animals to understand the real magnitude of reverse zoonosis and its potential risks. Implementing infection prevention and control measures to stop the virus circulation at the human-animal interface that includes One Health approach is essential.

Effectiveness of Modified Vaccinia Ankara-Bavaria Nordic Vaccination in a Population at High Risk of Mpox: A Spanish Cohort Study

BACKGROUND

With more than 7500 cases reported since April 2022, Spain has experienced the highest incidence of mpox in Europe. From 12 July onward, the modified vaccinia Ankara-Bavaria Nordic (MVA-BN) smallpox vaccine was offered as pre-exposure prophylaxis for those receiving pre-exposure prophylaxis for human immunodeficiency virus (HIV-PrEP). Our aim was to assess the effectiveness of 1 dose of MVA-BN vaccine as pre-exposure prophylaxis against mpox virus (MPXV) infection in persons on HIV-PrEP.

METHODS

National retrospective cohort study between 12 July and 12 December 2022. Individuals aged ≥18 years receiving HIV-PrEP as of 12 July with no previous MPXV infection or vaccination were eligible. Each day, we matched individuals receiving a first dose of vaccine and unvaccinated controls of the same age and region. We used a Kaplan-Meier estimator, calculated risk ratios (RR) and vaccine effectiveness (VE = [1 - RR]x100).

RESULTS

We included 5660 matched pairs, with a median follow-up of 62 days (interquartile range, 24-97). Mpox cumulative incidence was 5.6 per 1000 (25 cases) in unvaccinated and 3.5 per 1000 (18 cases) in vaccinated. No effect was found during days 0-6 post-vaccination (VE, -38.3; 95% confidence interval [CI], -332.7 to 46.4), but VE was 65% at ≥7 days (95% CI, 22.9 to 88.0) and 79% at ≥14 days (95% CI, 33.3 to 100.0) post-vaccination.

CONCLUSIONS

One dose of MVA-BN vaccine offered protection against mpox in most-at-risk population shortly after the vaccination. Further studies need to assess the VE of a second dose and the duration of protection over time.

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.

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".

Mpox in people living with HIV

PURPOSE OF REVIEW

The 2022 global outbreak of mpox disproportionally affected people with HIV (PWH). We review the data on the presentation, treatment, and prevention of mpox in PWH.

RECENT FINDINGS

Most PWH with mpox had a mild and self-limiting illness, no different to people without HIV. A higher rate of rectal symptoms has been reported among PWH and those with advanced HIV disease were at higher risk of severe disease, hospitalization, and death. Treatment with antivirals was widely used in hospitalized patients without any randomized control trial data to support its use and without any data specifically in PWH. Use of smallpox vaccines to prevent mpox is safe in PWH regardless of CD4+ cell count. There is limited data on efficacy in those with lower CD4+ cell count and on long-term protective efficacy.

SUMMARY

PWH should be offered vaccination against mpox in line with national guidelines. PWH should be individually risk-assessed for severe mpox, based on their CD4+ cell count and co-morbidities and ideally recruited into treatment trials to build an evidence base on efficacy. HIV and other sexually transmitted infection testing should be offered to all people diagnosed with mpox.

Mpox in people with past infection or a complete vaccination course: a global case series

BACKGROUND

Since May, 2022, a large global outbreak of human mpox (formerly known as monkeypox) has predominantly affected men who have sex with men. The strain responsible, Clade IIb, has mutated substantially from precursors originating from the 2017-18 outbreak in Nigeria. Immunity to smallpox, another orthopoxvirus, via previous infection or vaccination provides lifelong immunity. However, since the 2022 mpox outbreak, recent clusters were described in individuals with presumed immunity through recent infection or vaccination. We aim to describe the epidemiological and clinical characteristics of mpox in individuals with past infection or vaccination to improve the understanding of this disease in the setting of previous immunity.

METHODS

In this global case series, international collaborators from nine countries provided data on individuals with PCR-confirmed mpox after documented previous infection or vaccination between May 11, 2022, and June 30, 2023. We excluded cases that could not confirm vaccination status or cases with partial immunisation or any doses received before the current multi-national mpox outbreak (cutoff date May 1, 2022). Data were collected via a case report spreadsheet that reported on dates of infection and vaccination, route of immunisation, demographic characteristics, clinical findings, HIV status, concomitant sexually transmitted infections, and markers of disease severity (mpox severity score system). We describe case epidemiology, clinical course, and mpox severity scores; all analyses were descriptive.

FINDINGS

We report mpox infections in 37 gay and bisexual men who have sex with men: seven individuals had mpox reinfections, 29 individuals had mpox infections that occurred after two appropriately spaced Modified Vaccinia Ankara-Bavarian Nordic vaccine courses, and one individual had an infection that met the criteria for both reinfection and infection after vaccination. The median age of individuals was 36 years (IQR 30-45; range 21-58). Those with natural immunity after initial infection had a shorter disease course with less mucosal disease upon reinfection than with their initial infection. Infections post-vaccination were characterised by few lesions, little mucosal disease, and minimal analgesia requirements; two people received oral tecovirimat. Overall, there were no deaths, no bacterial superinfections, and all individuals were managed in the ambulatory clinic with one hospital admission for a necrotising neck lesion.

INTERPRETATION

The epidemiology of people with mpox reinfection or infection post-vaccination was similar to other published cohorts during the 2022 outbreak-predominantly young, sexually active gay and bisexual men who have sex with men. Clinical features and outcomes of repeat infection and infection after vaccination appear to be less clinically severe than those described in 2022 case literature. Specifically, compared with the 2022 case series, these individuals in the present study had fewer confluent lesions, less mucosal involvement, reduced analgesia requirement, and fewer admissions. Natural immunity and vaccine-induced immunity are not fully protective against mpox infection. However, in this small series both disease duration and severity appear to be reduced.

FUNDING

None.

No evidence of asymptomatic monkeypox infection in a highly sexually active MSM population in Austria

BACKGROUND

The 2022 outbreak of monkeypox virus (MPXV) revealed new transmission routes. Incidence declined sharply in September 2022, and it remains unclear whether MPXV is circulating in asymptomatic individuals because of increased immunity.

OBJECTIVES

Our study aimed to assesss the number of asymtomatic MPXV carriers in individuals at high risk for STI.

METHODS

We analysed anal samples from asymptomatic highly sexually active men who have sex with men for the presence of MPXV.

RESULTS

We detected a high number of concomitant sexually transmitted infections but did not find a single sample with MPXV.

CONCLUSIONS

Our results indicate that the general recommendation to implement screening for MPXV is not currently justified.

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.

Strategic and scientific contributions of human challenge trials for vaccine development: facts versus fantasy

The unprecedented speed of delivery of SARS-CoV-2 pandemic vaccines has redefined the limits for all vaccine development. Beyond the aspirational 100-day timeline for tomorrow's hypothetical pandemic vaccines, there is a sense of optimism that development of other high priority vaccines can be accelerated. Early in the COVID-19 pandemic, an intense and polarised academic and public discourse arose concerning the role of human challenge trials for vaccine development. A case was made for human challenge trials as a powerful tool to establish early proof-of-concept of vaccine efficacy in humans, inform vaccine down selection, and address crucial knowledge gaps regarding transmission, pathogenesis, and immune protection. We review the track record of human challenge trials contributing to the development of vaccines for 19 different pathogens and discuss relevant limitations, barriers, and pitfalls. This Review also highlights opportunities for efforts to broaden the scope and boost the effects of human challenge trials, to accelerate all vaccine development.

Clinical review of human mpox

BACKGROUND

Historically, human mpox was predominantly a zoonotic disease occurring more frequently in rural children in Africa and characterized by a largely self-limiting febrile centrifugal monomorphic rash illness. However, the 2022 mpox global outbreak has shown that the disease is changing in many ways, including sustained human-to-human transmission via sexual contact, novel clinical presentations, and adverse associations between mpox and advanced HIV.

OBJECTIVES

The aim of this paper is to review the traditional and emerging clinical aspects of human mpox and provide updated information on the clinical course and outcome of the disease.

SOURCES

We searched electronic databases including PubMed and Google Scholar and identified relevant published literature on mpox.

CONTENT

The clinical presentation of human mpox is influenced by the route of infectious exposure, the strain and dose of the infecting virus, and the host immune system. Exposure to the virus can result in sub-clinical or clinical diseases of variable severity. Infections caused by clade I viral strains are more severe than class IIa and IIb strains, which are associated with a milder febrile rash illness, and with anogenital skin lesions in clade IIb infections. Most cases of mpox recover entirely within 2-4 weeks after onset of illness and a few develop skin-related sequelae. Overall, people with advanced HIV infection, children <5 years of age, and pregnant women may present with more severe disease and higher case fatalities.

IMPLICATIONS

The continued endemicity of the classical mpox in Africa, the emergence of a new clinical form of the disease during the 2022 global outbreak, and the adverse associations between advanced HIV and mpox have implications for the surveillance, clinical diagnosis, and management of human mpox.

Acceptance and timeliness of post-exposure vaccination against mpox in high-risk contacts, Amsterdam, the Netherlands, May-July 2022

BACKGROUND

May 2022, several countries reported mpox outbreaks among men-who-have-sex-with-men. In the Netherlands, high-risk contacts were offered the third-generation smallpox vaccine as post-exposure-prophylaxis (PEP) within 4 but maximum 14 days after exposure. We investigated their PEP acceptance, timeliness of uptake and development of mpox for the region of the Public Health Service (PHS) Amsterdam.

METHODS

High-risk contacts identified during 20 May-22 July 2022 were included. Contacts were followed-up 21 days after exposure and classified as: no patient (no mpox symptoms or orthopoxvirus PCR-negative) or mpox patient (clinically suspected mpox or orthopoxvirus PCR-positive). We calculated time intervals between date of last exposure and first PHS consultation, PEP administration, and symptom onset.

RESULTS

Two-hundred-ninety contacts were at high-risk of mpox predominantly due to sexual and/or direct skin-skin contact (212/290, 73 %). First PHS consultation was a median of 5 (IQR 3, 7) days after exposure, at which point 26/290 (9 %) contacts were ineligible for PEP. 84 % (223/264) of contacts eligible for PEP, received PEP within a median of 6 (IQR 3, 8) days after exposure. Of 282 contacts (missing outcome n = 8) 38 (14 %) developed mpox a median of 7 (IQR 5, 12) days after exposure, of whom 50 % (19/38) developed mpox before their first PHS consultation. Among contacts eligible for PEP, 2/38 (5 %) unvaccinated and 16/218 (7 %) vaccinated contact developed mpox.

CONCLUSIONS

PEP acceptance among contacts of mpox patients was high. However, PEP timeliness was inadequate. Half of contacts received PEP 6 or more days after exposure, and half of contacts who developed mpox had an onset prior to their first PHS consultation. Estimating PEP vaccine effectiveness is problematic due to the timeliness of PEP and the time it takes to generate vaccine-induced immunity. It is important to assess how PEP timeliness may improve and to promote pre-exposure vaccination to control mpox outbreaks.

Systematic Review on the Efficacy, Effectiveness, Safety, and Immunogenicity of Monkeypox Vaccine

BACKGROUND

The variation in the reported vaccine safety and effectiveness could contribute to the high rates of vaccine hesitancy among the general population and healthcare workers in areas where monkeypox (mpox) is circulating. In this review, our objective was to evaluate the safety, immunogenicity, effectiveness, and efficacy of the mpox vaccines.

METHODS

An extensive search for articles across multiple databases was performed, including searching six databases (PubMed Central, PubMed Medline, Scopus, Web of Science, Cochrane, ProQuest), two pre-print databases (European PMC Preprint and MedRxiv), and Google Scholar.

RESULTS

A total of 4290 citations were retrieved from the included databases. Following the removal of duplicates and the initial screening of records, a total of 36 studies were included into the analysis. Additionally, we identified five more studies through manual searches, resulting in a total of 41 eligible articles for qualitative synthesis. The study findings revealed that mpox vaccines demonstrate the ability to generate adequate antibodies; however, their effectiveness may decrease over time, exhibiting varying safety profiles. Most of the included studies consistently reported substantial levels of effectiveness and efficacy against mpox. Interestingly, the number of vaccine doses administered was found to influence the degree of immunogenicity, subsequently impacting the overall effectiveness and efficacy of the vaccines. Furthermore, we found that smallpox vaccines exhibited a form of cross-protection against mpox.

CONCLUSIONS

Vaccines can be used to prevent mpox and effectively control its spread.

A Review of the Past, Present, and Future of the Monkeypox Virus: Challenges, Opportunities, and Lessons from COVID-19 for Global Health Security

Monkeypox, a rare but significant zoonotic and orthopoxviral disease, has garnered increasing attention due to its potential for human-to-human transmission and its recent resurgence in multiple countries throughout Europe, North America, and Oceania. The disease has emerged as a novel threat to the global health systems that are still striving to recover from the major shocks of the COVID-19 pandemic. The unusual manifestation of the illness highlights a substantial knowledge deficit and necessitates the immediate development of a public health action strategy, considering the epidemiological differences observed in the ongoing outbreak and the appearance of cases in non-endemic nations. This literature review aims to synthesize existing knowledge on monkeypox, encompassing its historical context, etiology, epidemiology, surveillance, prevention, transmission, clinical presentation, diagnosis, treatments, and recent outbreak. Particular attention is given to both advances and gaps in our understanding of monkeypox, and we point toward future directions for research and intervention efforts as pertains to vaccine development and distribution. Lastly, we will also review the recent outbreak through a sociopolitical lens as relates to decision-making strategies, especially given the lessons learned from COVID-19.

Characteristics of Mpox Infections in Louisiana in the 2022 Outbreak

The 2022 outbreak of mpox in Louisiana was limited to just >300 cases, perhaps an unexpected outcome given the state's high rates of HIV and other sexually transmitted infections (STIs). We aimed to describe the local outbreak within two health centers in the New Orleans region, partnering with the Louisiana Department of Health to offer additional statewide data. We reviewed charts of persons testing positive for mpox in New Orleans from July to November 2022 at two local health centers that together accounted for half of local cases. We abstracted data on HIV status, immune function [CD4 count, viral load (VL)], antiretroviral therapy regimen, symptoms and severity of infection, vaccination status, and whether tecovirimat was administered. We present local data relative to statewide data (July 2022-January 2023). Of 103 individuals in our network for whom charts were reviewed, 96 (93%) identified as male, 52 (50%) were Black, and 69 (67%) had HIV, including 12 (17%) with uncontrolled HIV (CD4 < 200 cells/mm3 or VL >200 copies/mL). The most common presenting symptoms were rash (n = 71, 69%), fever (n = 36, 35%), and rectal pain (n = 33, 32%). Of six (6%) patients hospitalized, four (67%) were persons with HIV (PWH). Two were hospitalized for severe mpox infection with >100 lesions at presentation; both were PWH, and one had uncontrolled infection. Across the state, 307 cases have been identified and 24 have been hospitalized. Of those hospitalized, 18 (75%) were PWH, including 9 (50%) with uncontrolled HIV. The demographic data from Louisiana, a state with high prevalence of STIs and HIV/AIDS, are consistent with prior reports describing the 2022 mpox outbreak. Our results contribute to accumulating data on the severity of infection in individuals with HIV-related immunocompromise.

Efficacy of smallpox vaccines against Mpox infections in humans

The Mpox virus (MPXV) is endemic in certain countries in Central and West Africa, where several mammalian species, especially rodents, are natural reservoirs. However, the MPXV can infect nonhuman primates and cause zoonotic infections in humans after close contact with an infected animal. Human-to-human transmission of MPXV can also occur through direct close contact with an infected individual or infected materials. In May 2022 an initial cluster of human Mpox cases was identified in the UK, with the first case confirmed in a patient who had recently travelled to Nigeria. The infection subsequently spread via human-to-human transmission within the UK and Mpox cases began to appear in many other countries around the world where the MPXV is not endemic. No specific treatments for MPXV infection in humans are available. However, data from studies undertaken in Zaire in the 1980s revealed that those with a history of smallpox vaccination during the global smallpox eradication campaign also had good cross-protection against MPXV infection. However, the vaccines used during the global eradication campaign are no longer available. During the 2022 global Mpox outbreak over a million doses of the Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN) smallpox vaccine were offered either as pre or postexposure prophylaxis to those at high risk of MPXV infection. Here, we review what has been learned about the efficacy of smallpox vaccines in reducing the incidence of MPXV infections in high-risk close contacts.

Development of a novel serological assay for the detection of mpox infection in vaccinated populations

In 2022 the World Health Organization declared a Public Health Emergency for an outbreak of mpox, the zoonotic Orthopoxvirus (OPV) affecting at least 104 nonendemic locations worldwide. Serologic detection of mpox infection is problematic, however, due to considerable antigenic and serologic cross-reactivity among OPVs and smallpox-vaccinated individuals. In this report, we developed a high-throughput multiplex microsphere immunoassay using a combination of mpox-specific peptides and cross-reactive OPV proteins that results in the specific serologic detection of mpox infection with 93% sensitivity and 98% specificity. The New York State Non-Vaccinia Orthopoxvirus Microsphere Immunoassay is an important tool to detect subclinical mpox infection and understand the extent of mpox spread in the community through retrospective analysis.

Real-world effectiveness of monkeypox vaccines: a systematic review

A systematic review was conducted to investigate and understand the real-world effectiveness of smallpox vaccines against mpox during 2022 outbreaks. The effectiveness of MVA-BN was estimated to be 87% [95% confidence interval (CI): 84–90%] for one-dose and 89% (95% CI: 78–100%) for two-dose vaccination. The next-generation vaccines are recommended for future preparedness.

Update on Mpox: a brief narrative review

Mpox (formerly Monkeypox), a neglected tropical disease once confined to Central and West Africa, emerged as a global epidemic outbreak in May, 2022 with 87,529 cases reported as of May, 23, 2023. It predominantly affected men (96.2%) who have sex with men (84-100%), although other transmission routes have been reported, including occupational exposure and vertical transmission. Concomitant HIV infection has been recorded in 21-46.9% and pre-exposure prophylaxis against HIV infection has been reported in 11-57% of published cases. The current outbreak clinical presentation differs from endemic cases with prodromal symptoms that could be absent: the number of lesions is generally low, with skin lesions predominantly localised in the ano-genital areas and frequent lesions present in different stages of progression (i.e., asynchronous). Asymptomatic Mpox infection can occur in 1.8-6.5% of at-risk subjects. People living with HIV with severe immunodeficiency (less than 100 CD4+ lymphocytes per microliter) are at risk of more severe clinical manifestations and death. According to a systematic review and meta-analysis, the hospitalisation rate is around 6% and the observed case-fatality rate is less than 0.1%. Tecovirimat is the drug of choice for treating severe cases although there is no evidence of efficacy from randomised controlled trials. Immunization with a live non-replicating vaccine (JYNNEOS) effectively reduces the disease's incidence.

Mpox: an updated review of dermatological manifestations in the current outbreak

Mpox is a disease caused by a double-stranded DNA orthopoxvirus discovered in 1958. In 2022, an outbreak on an unprecedented scale marked its transition from neglected, zoonotic disease circulating almost exclusively within African borders to sexually transmitted infection (STI) of international concern. Although phylogenetic evidence suggests progressive evolution from the strain associated with the 2018 outbreak in Nigeria, epidemiological links with previous cases have still not been completely elucidated. Clinically, mpox presents with systemic symptoms, such as fever, headache, malaise and a characteristic cutaneous eruption, similar to that of cognate viruses (e.g. smallpox). Mpox pseudopustules evolve through several stages, including umbilication and crusting, and resolve in the span of 2-3 weeks. The hallmarks that set the 2022 outbreak apart from classic mpox were a disproportionate number of cases occurring in men who have sex with men, an often localized cutaneous picture and a significant burden in terms of concomitant STIs. Investigations into the disease pathogenesis, related immune response, clinical and dermoscopic features, in addition to studies aimed at defining novel management strategies, have advanced mpox knowledge considerably. Herein, recent findings on mpox are reviewed, with a keen focus on dermatological manifestations and their implications in the current diagnostic scenario, reinforcing the pivotal role of dermatologists in managing suspect cases and preventing further spread of the contagion.

Immunogenicity and Safety of Modified Vaccinia Ankara (MVA) Vaccine-A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Prevention of mpox has become an important public health interest. We aimed to evaluate the safety and immunogenicity of the Modified Vaccinia Ankara (MVA) vaccine. We conducted a systematic review and meta-analysis of randomized-controlled trials (RCTs) comparing MVA versus no intervention, placebo, or another vaccine. Outcomes included safety and immunogenicity outcomes. We also performed a systematic review of RCTs evaluating various MVA regimens. Fifteen publications were included in the quantitative meta-analysis. All but one (ACAM2000) compared MVA with placebo. We found that cardiovascular adverse events following two MVA doses were significantly more common compared to placebo (relative risk [RR] 4.07, 95% confidence interval [CI] 1.10-15.10), though serious adverse events (SAEs) were not significantly different. Following a single MVA dose, no difference was demonstrated in any adverse event outcomes. Seroconversion rates were significantly higher compared with placebo after a single or two doses. None of the RCTs evaluated clinical effectiveness in preventing mpox. This meta-analysis provides reassuring results concerning the immunogenicity and safety of MVA. Further studies are needed to confirm the immunogenicity of a single dose and its clinical effectiveness. A single vaccine dose may be considered according to vaccine availability, with preference for two doses.

Clinical Features, Antiviral Treatment, and Patient Outcomes: A Systematic Review and Comparative Analysis of the Previous and the 2022 Mpox Outbreaks

BACKGROUND

This study aims to comparatively analyze clinical features, treatment, and patient outcomes between the previous and the 2022 mpox (monkeypox) outbreaks.

METHODS

Five bibliographic databases were searched for studies reporting clinical features, management, and patient outcomes of mpox. Systematic review and meta-analysis were performed.

RESULTS

In total, 73 studies were included in the systematic review, of which 33 studies were subjected to meta-analysis. Previous outbreaks substantially affected children, whereas the 2022 outbreak primarily affected male adults, of which 94.66% (95% confidence interval [CI], 88.03-98.95) were men who have sex with men. Furthermore, 72.47% (95% CI, 51.04-89.71) reported high-risk sexual activity and the overall human immunodeficiency virus (HIV) prevalence was 37.65% (95% CI, 30.09-45.50). Skin lesions remain the typical symptom; however, their anatomic distribution differed. Systemic manifestations were common, but rectal pain was unique to the 2022 outbreak. The estimated overall fatality during past outbreaks in Africa was 4.61% (95% CI, 2.39%-7.35%), whereas 6.34% (95% CI, 3.35%-10.10%) of patients from the 2022 outbreak required hospitalization. Antiviral treatment, in particular tecovirimat, has been prescribed for a subset of patients, but the efficacy remains inconclusive.

CONCLUSIONS

These findings are important for better understanding the disease and guiding adequate response to mpox outbreaks.

Mpox and HIV: a Narrative Review

PURPOSE OF REVIEW

We reviewed the available literature on mpox in People with HIV (PWH). We highlight special considerations of mpox infection related to epidemiology, clinical presentation, diagnostic and treatment considerations, prevention, and public health messaging in PWH.

RECENT FINDINGS

During the 2022 mpox outbreak, PWH were disproportionally impacted worldwide. Recent reports suggest that the disease presentation, management, and prognosis of these patients, especially those with advanced HIV disease, can widely differ from those without HIV-associated immunodeficiency. Mpox can often be mild and resolve on its own in PWH with controlled viremia and higher CD4 counts. However, it can be severe, with necrotic skin lesions and protracted healing; anogenital, rectal, and other mucosal lesions; and disseminated organ systems involvement. Higher rates of healthcare utilization are seen in PWH. Supportive, symptomatic care and single or combination mpox-directed antiviral drugs are commonly used in PWH with severe mpox disease. Data from randomized clinical control trials on the efficacy of therapeutic and preventive tools against mpox among PWH are needed to better guide clinical decisions.

Demographic Disparities in Mpox Vaccination Series Completion, by Route of Vaccine Administration - California, August 9, 2022-March 31, 2023

In August 2022, the Food and Drug Administration authorized JYNNEOS vaccine (modified vaccinia Ankara vaccine, Bavarian Nordic), a 2-dose series used for the prevention of Monkeypox virus infection, to be administered via a dose-sparing intradermal route, in addition to the previously authorized subcutaneous route. The California Department of Public Health investigated whether demographic disparities in vaccination series completion varied by route of administration of the recipient's first dose. Among California residents who received their first dose during August 9, 2022-March 31, 2023, a total of 59.8% received a second dose. Series completion was highest among non-Hispanic White persons (64.1%), persons aged ≥65 years (72.6%), and adults with male sex assignment at birth (62.1%); series completion was lowest among non-Hispanic Black or African American persons (51.3%), persons aged 18-24 years (42.9%), and adults assigned female sex at birth (42.8%). When the first dose was received by subcutaneous administration, overall series completion was 58.8% compared with 60.2% when the first dose was administered intradermally. Odds of series completion across all race and ethnicity groups, persons aged 18-64 years, community health conditions, and persons assigned male sex at birth were not greater when the first dose was administered subcutaneously compared with intradermally. Intradermal use of JYNNEOS vaccine did not lower overall 2-dose series completion rates. Continued efforts are needed to ensure persons at risk for Monkeypox virus infection receive both recommended doses.

Characteristics of Mpox Vaccine Recipients Among a Sample of Men Who Have Sex With Men With Presumed Exposure to Mpox

ABSTRACT

Mpox vaccination is recommended for persons exposed to or at risk for mpox. Approximately 25% of an online sample of men who have sex with men (MSM) with presumed mpox exposure were vaccinated (≥1 dose). Vaccination was higher among younger MSM, MSM concerned about mpox, or MSM reporting sexual risk behaviors. Incorporating mpox vaccination into routine sexual health care and increasing 2-dose vaccination uptake is essential to preventing mpox acquisition, improving MSM sexual health, and averting future mpox outbreaks.

Vaccine Effectiveness of JYNNEOS against Mpox Disease in the United States

BACKGROUND

In the United States, more than 30,000 cases of mpox (formerly known as monkeypox) had occurred as of March 1, 2023, in an outbreak disproportionately affecting transgender persons and gay, bisexual, and other men who have sex with men. In 2019, the JYNNEOS vaccine was approved for subcutaneous administration (0.5 ml per dose) to prevent mpox infection. On August 9, 2022, an emergency use authorization was issued for intradermal administration (0.1 ml per dose); however, real-world effectiveness data are limited for either route.

METHODS

We conducted a case-control study based on data from Cosmos, a nationwide Epic electronic health record (EHR) database, to assess the effectiveness of JYNNEOS vaccination in preventing medically attended mpox disease among adults. Case patients had an mpox diagnosis code or positive orthopoxvirus or mpox virus laboratory result, and control patients had an incident diagnosis of human immunodeficiency virus (HIV) infection or a new or refill order for preexposure prophylaxis against HIV infection between August 15, 2022, and November 19, 2022. Odds ratios and 95% confidence intervals were estimated from conditional logistic-regression models, adjusted for confounders; vaccine effectiveness was calculated as (1 - odds ratio for vaccination in case patients vs. controls) × 100.

RESULTS

Among 2193 case patients and 8319 control patients, 25 case patients and 335 control patients received two doses (full vaccination), among whom the estimated adjusted vaccine effectiveness was 66.0% (95% confidence interval [CI], 47.4 to 78.1), and 146 case patients and 1000 control patients received one dose (partial vaccination), among whom the estimated adjusted vaccine effectiveness was 35.8% (95% CI, 22.1 to 47.1).

CONCLUSIONS

In this study using nationwide EHR data, patients with mpox were less likely to have received one or two doses of JYNNEOS vaccine than control patients. The findings suggest that JYNNEOS vaccine was effective in preventing mpox disease, and a two-dose series appeared to provide better protection. (Funded by the Centers for Disease Control and Prevention and Epic Research.).

Predictors of Mpox vaccine uptake among sexual and gender minority young adults living in Illinois: Unvaccinated vs. double vs. single dose vaccine recipients

INTRODUCTION

The 2022 global outbreak of Monkeypox virus (Mpox), which has primarily spread through the sexual networks of sexual and gender minority (SGM) individuals, has introduced new public health challenges. While an efficacious Mpox vaccine is in active circulation, few Mpox vaccine studies have examined its uptake among SGM groups. The aims of this study were to investigate (a) the prevalence of Mpox vaccine uptake among SGM and (b) the contextual, Mpox-disease specific, and Mpox-vaccine specific factors associated with Mpox vaccine among SGM.

METHODS

We conducted a cross-sectional survey in Illinois, USA in September 2022; 320 young SGM completed self-administered questionnaires. Multinomial logistic regression was used to assess the contextual, Mpox-disease specific, and Mpox-vaccine specific factors associated with Mpox vaccine uptake. Adjusted Odds Ratios (aORs) and 95 % Confidence Intervals (CI) are reported.

RESULTS

Approximately 50 % of the SGM participants included in this study had received at least their first dose of the Mpox vaccine. Multinomial regression analysis showed that individuals who had recently experienced food insecurity, had higher degrees of fear of social rejection due to Mpox acquisition, and were more Mpox-vaccine hesitant were more likely to be unvaccinated. Conversely, knowing people who have contracted Mpox, having higher formal educational attainment, having higher degrees of Mpox-related internalized heterosexism, and being more concerned about one's safety regarding Mpox morbidity were more likely to be double-dosers.

CONCLUSION

Approximately 50 % of the SGMs included in this study received at least their first dose of the Mpox vaccine; however, only one-quarter of participants completed the recommended 2-dose Mpox regimen. Our findings indicate that socioeconomic stability, fear of social rejection due to disease acquisition, and Mpox-specific vaccine hesitancy may be important structural targets to consider when developing vaccine-uptake prevention and intervention strategies tailored to the needs of sexual and gender minorities.