Mpox vaccine and infection-driven human immune signatures: an immunological analysis of an observational study

Public antibodies: convergent signatures in human humoral immunity against pathogens

The human humoral immune system has evolved to recognize a vast array of pathogenic threats. This ability is primarily driven by the immense diversity of antibodies generated by gene rearrangement during B cell development. However, different people often produce strikingly similar antibodies when exposed to the same antigen-known as public antibodies. Public antibodies not only reflect the immune system's ability to consistently select for optimal B cells but can also serve as signatures of the humoral responses triggered by infection and vaccination. In this Minireview, we examine and compare public antibody identification methods, including the identification criteria used based on V(D)J gene usage and similarity in the complementarity-determining region three sequences, and explore the molecular features of public antibodies elicited against common pathogens, including viruses, protozoa, and bacteria. Finally, we discuss the evolutionary significance and potential applications of public antibodies in informing the design of germline-targeting vaccines, predicting escape mutations in emerging viruses, and providing insights into the process of affinity maturation. The ongoing discovery of public antibodies in response to emerging pathogens holds the potential to improve pandemic preparedness, accelerate vaccine design efforts, and deepen our understanding of human B cell biology.

T cell memory response to MPXV infection exhibits greater effector function and migratory potential compared to MVA-BN vaccination

In 2022, a global mpox outbreak occurred, and remains a concern today. The T cell memory response to MPXV (monkeypox virus) infection has not been fully investigated. In this study, we evaluate this response in convalescent and MVA-BN (Modified Vaccinia Ankara - Bavarian Nordic) vaccinated individuals using VACV-infected cells. Strong CD8+ and CD4+ T cell responses are observed, and T cell responses are biased towards viral early expressed proteins. We identify seven immunodominant HLA-A*02:01 restricted MPXV-specific epitopes and focus our detailed phenotypic and scRNAseq analysis on the immunodominant HLA-A*02:01-G5R18-26-specific CD8+ T cell response. While tetramer+CD8+ T cells share similar differentiation and activation phenotypes, T cells from convalescent individuals show greater cytotoxicity, migratory potential to site of infection and TCR clonal expansion. Our data suggest that effective functional profiles of MPXV-specific memory T cells induced by Mpox infection may have an implication on the long-term protective responses to future infection.

The impact of orthopoxvirus vaccination and Mpox infection on cross-protective immunity: a multicohort observational study

BACKGROUND

Cross-reactive immune memory responses to orthopoxviruses in humans remain poorly characterised despite their relevance for vaccine design and outbreak control. We aimed to assess the magnitude, specificity, and durability of cross-reactive immune responses elicited by smallpox vaccines and mpox virus infection.

METHODS

We did a multicohort observational study involving participants from the USA, Brazil, and Portugal across four groups: Dryvax (first-generation smallpox vaccine) recipients vaccinated 40-80 years ago, JYNNEOS (third-generation smallpox vaccine) recipients vaccinated within the past year, a cohort receiving both vaccines, and patients infected with clade IIb mpox. Samples were analysed for systemic and mucosal humoral responses, neutralising antibody titres, viral antigen structural analysis, and T-cell cross-reactivity to vaccina virus, cowpox virus, and mpox virus. Statistical analyses included correlation assessments and comparisons across cohorts to determine the magnitude, longevity, and breadth of immune responses.

FINDINGS

Between July 7, 2022, and Aug 3, 2023, 262 participants were recruited, resulting in analysis of 378 samples. Both first-generation and third-generation smallpox vaccines elicited vaccinia virus-reactive and mpox virus-reactive antibodies, with the strongest responses targeting the less conserved extracellular virion antigens B5 and A33. Despite high concentrations of anti-mpox virus antibodies in the plasma, cross-neutralisation activity correlated with viral antigenic distance. Higher neutralisation was observed for cowpox virus than for mpox virus, which has lower antigenic conservation with vaccina virus. Complement-mediated neutralisation enhanced mpox virus neutralisation, overcoming the limitations of antigenic distance. Dryvax recipients sustained vaccina virus neutralisation titres for over 80 years, whereas cross-reactive responses did not show this durability. JYNNEOS-induced responses waned within a year. T-cell cross-reactivity was long-lasting, detected up to 70 years after vaccination. Booster vaccinations augmented the magnitude, breadth, and longevity of cross-neutralising responses.

INTERPRETATION

Our findings highlight the potential combined role of antibody effector functions and T-cell memory in cross-protection against orthopoxviruses. Complement-mediated neutralisation enhances cross-protection, overcoming antigenic distance. These Fc-mediated functions, along with T-cell responses, contribute to effective and long-lasting immunity conferred by smallpox vaccines against other orthopoxviruses.

FUNDING

Yale University and Stavros Niarchos Foundation Institute for Global Infectious Disease.

Kinetics of the humoral and cellular immune response up to 1 year from mpox virus infection

OBJECTIVES

The immunological signature of mpox Clade IIb was described in the early stages of infection. We aimed to characterize the kinetics of both humoral and cellular immune responses against mpox from the onset of symptoms up to one year later.

METHODS

Sixty-nine patients with mpox infected with Clade IIb during the 2022 outbreak were included in a longitudinal study. Blood samples were collected during the first 3 weeks and 3-4 (T3-4M), 6-8 (T6-8M), and 12 months (T12M) after infection. Mpox-specific IgM, IgA, IgG, and neutralizing antibodies (nAbs) titres were measured by immunofluorescence assay and 50% plaque reduction neutralization test. Interferon-γ producing specific T-cells to Modified Vaccinia Ankara (MVA) peptides was assessed by ELISpot assay. CD4+ and CD8+ T-cells phenotypic markers (CD38/CD57/PD-1) were performed by flow cytometry.

RESULTS

All the humoral markers were detected as early as 4 days and peaked at week 2 (IgG) or 3 (IgM, IgA, nAbs) from symptoms onset. At T3-4M from onset, the antibody levels decreased, and IgM was detected in only one patient; IgA in 50% (13/26), IgG and nAbs in 92% (24/26) of participants. Further decreases in IgG and nAb mean titres were observed at 6-8M. At T12M, IgM, IgA, IgG, and nAbs were detected in 4 (2/47), 48 (23/47), 93 (44/47) and 78% (37/47) of patients, respectively. MVA-specific T-cell response was detected early in the acute phase of infection, peaked at T3M and are maintained until T12M.

DISCUSSION

These data provide evidence of persistence of humoral and cellular immune response 1 year after natural infection, suggesting the maintenance of adequate immune memory. Further study is needed to assess longer persistence of immunity and the cross-protection against different mpox clades.

Recent Advances in Mpox Epidemic: Global Features and Vaccine Prevention Research

Monkeypox (mpox) is a zoonotic disease (zoonose) caused by the monkeypox virus (MPXV). MPXV, a member of the Orthopoxviridae family, is categorized into two clades, Central Africa (I) and West Africa (II), each of which is further subdivided into subclades a and b. Clade I generally causes more serious illness and higher mortality rates, while Clade II results in milder illness. Historically, mpox epidemics were localized to specific regions and countries in Africa. Since 2022, the mpox epidemic, fueled by MPXV Clade IIb, has swiftly spread across various nations and regions, jeopardizing public health and safety. However, starting in 2024, Clade Ib gradually replaced Clade IIb. The notable genetic variation in Clade Ib may provide MPXV with new opportunities to evade the immune system and adapt to hosts. According to the World Health Organization (WHO), from 1 January 2022, to 24 November 2024, there were 117,663 confirmed cases and 2 probable cases, resulting in 263 deaths across 127 Member States in all six WHO regions. As of 9 January 2025, 12 countries outside Africa have reported imported MPXV Clade Ib cases, with secondary cases emerging in the United Kingdom, Germany, and China. Due to the incomplete development of a vaccine specifically for MPXV, the smallpox vaccine remains in use for preventing mpox or for emergency vaccination post-exposure. Therefore, the persistent spread of mpox is still a major concern, requiring greater awareness and vaccination efforts in populations at high risk. This paper aims to summarize the etiological characteristics, epidemic situation, and vaccine prevention efforts for mpox, offering a reference for managing this serious epidemic and ensuring effective scientific prevention and control.

Immunogenicity of MVA-BN vaccine deployed as mpox prophylaxis: a prospective, single-centre, cohort study and analysis of transcriptomic predictors of response

BACKGROUND

Since 2022, mpox has emerged as a global health threat, with two clades (I and II) causing outbreaks of international public health concern. The third generation smallpox vaccine modified vaccinia Ankara, manufactured by Bavarian Nordic (MVA-BN), has emerged as a key component of mpox prevention. To date, the immunogenicity of this vaccine, including determinants of response, has been incompletely described, especially when MVA-BN has been administered intradermally at a fifth of the registered dose (so-called fractionated dosing), as recommended as a dose-sparing strategy. The aim of this study was to explore the immunogenicity of MVA-BN and baseline determinants of vaccine response in an observational public-health response setting.

METHODS

We conducted a prospective cohort study and immunological analysis of responses to MVA-BN in patients attending a sexual health vaccination clinic in Oxford, UK. Blood samples were taken at baseline, day 14, and day 28 after first vaccine, and 28 and 90 days following a second vaccine. A subcohort had additional blood samples collected day 1 following their first vaccine (optional timepoint). We assessed IgG responses to mpox and vaccinia antigens using Luminex assay (MpoxPlex) using generalised linear mixed modelling, and T-cell responses using IFN-γ enzyme-linked immunospot and activation-induced marker assay. Associations between blood transcriptomic signatures (baseline, day 1) and immunogenicity were assessed using differential expression analysis and gene set enrichment methods.

FINDINGS

We recruited 34 participants between Dec 1, 2022 and May 3, 2023 of whom 33 received fractionated dosing. Of the 30 without previous smallpox vaccination, 14 (47%) seroconverted by day 28, increasing to 25 (89%) 90 days after second vaccination. However, individuals seronegative on day 28 had persistently lower responses compared with individuals seropositive on day 28 (numerically lower antibody responses to six of seven dynamic antigens in the MPoxPlex assay, p<0·05). Serological response on day 28 was positively associated with type I and II interferon signatures 1 day after vaccination (n=18; median module score 0·13 vs 0·06; p=1·1 × 10-⁶), but negatively associated with these signatures at baseline (normalised enrichment score -2·81 and -2·86, respectively).

INTERPRETATION

Baseline inflammatory states might inhibit MVA-BN serological immunogenicity by inhibiting the upregulation of MVA-induced innate immune signalling. If confirmed mechanistically, these insights could inform improved vaccination strategies against mpox in diverse geographic and demographic settings. Given the likelihood of vaccine supply limitations presently and in future outbreak settings, the utility of dose-sparing vaccine strategies as a general approach to maximising population benefit warrants further study.

FUNDING

UKRI via the UK Monkeypox Research Consortium, Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences, the Kennedy Trust for Rheumatology Research, the John Climax Donation, the Medical Research Council (UK), the Wellcome Trust, the Center for Cooperative Human Immunology (National Institutes of Health), and the National Institute for Health and Care Research Oxford Biomedical Research Centre.

Monkeypox Virus Infection Stimulates a More Robust and Durable Neutralizing Antibody Response Compared to Modified Vaccinia Virus Ankara Vaccination

Monkeypox virus (MPXV) has recently caused a global disease outbreak in humans. Differences in the neutralizing antibody response to vaccination versus MPXV infection remain poorly understood. Here, we examined the neutralization of MPXV and vaccinia virus by sera from a cohort of convalescent and vaccinated individuals at 1 and 8 months postexposure. Convalescent individuals displayed higher neutralizing antibody titers against MPXV than vaccinated and MPXV-naive persons at 1 month postexposure. Neutralizing antibody titers had waned significantly in both groups at 8 months. This study suggests that additional vaccine strategies are needed to elicit a durable humoral response and prevent breakthrough infections.

Assessment of MpoxPlex, a high-throughput and multiplexed immunoassay: a diagnostic accuracy study

BACKGROUND

In May, 2022, the first global outbreak of mpox (formerly known as monkeypox) occurred. In response, public health agencies in the UK have made smallpox vaccines available to individuals at the highest risk of infection. With mpox cases still being detected globally, novel tools are required to aid with diagnosis, serosurveillance, and the evaluation of immune responses following infection and immunisation with current and new vaccine candidates. Here, we describe the development of a multiplexed immunoassay, MpoxPlex, able to measure IgG responses to 12 Orthopoxvirus antigens concurrently and distinguish between responses to infection and vaccination.

METHODS

Using the Luminex (DiaSorin, Saluggia, Italy) platform, antibody responses to vaccinia virus (VACV) antigens B5, A27, and A33 and monkeypox virus (MPXV) antigens E8, B6, B2, M1, A27, A35, H3, A29, and A5 were assessed in serum from individuals after MPXV infection (n=24) and after vaccination (n=75) with modified VACV Ankara-Bavarian Nordic. Assay characteristics and cutoffs were calculated by fitting receiver operating characteristic curves to the median fluorescence intensities of these positive samples and negative samples that were run alongside (n=435). P values were calculated using non-parametric Mann-Whitney, Kruskal-Wallis, and Dunn's multiple comparisons tests.

FINDINGS

Using the results from a combination of eight antigens, we were able to distinguish samples as either post-vaccination or post-infection from negative samples with a sensitivity of 98% and a specificity of 95%. IgG responses to MPXV antigen A27 were able to distinguish post-MPXV infection with a sensitivity of 88% and a specificity of 97%. VACV antigen A27 and MPXV antigens A29 and A5 provided little diagnostic advantage.

INTERPRETATION

With additional benefits over current serological assays, we believe this assay will provide substantial insight into the current global outbreak of mpox. MpoxPlex shows use for both serosurveillance and immunological studies of vaccination and infection.

FUNDING

Grant-in-aid funding to the Emerging Pathogen Serology Group at Porton Down, UK Health Security Agency.

Identification of neutralizing nanobodies protecting against poxvirus infection

An outbreak of mpox has triggered concerns regarding the adequacy of intervention strategies. Passive immunity conferred by neutralizing antibodies exhibits potential in the prophylaxis and treatment of orthopoxvirus infections. Despite this, the investigations of effective antibody therapeutics have been hindered by the varied nature of orthopoxvirus envelope proteins and the intricate mechanisms underpinning viral invasion. Our study involves the production of six mpox virus (MPXV) envelope proteins, which are relatively conservative and considered to play a role in the neutralization process. We employed a synthetic nanobody (Nb) library to derive a broad array of specific Nbs against these viral proteins. We identified a cross-reactive Nb, termed M1R-01, which targets the M1R protein and effectively neutralizes both vaccinia virus (VACV) and MPXV. Notably, the M1R-01-based antibody strategy provided optimal protection against a lethal VACV challenge in mice. Additionally, we determined the crystal structure of the M1R-Nb complex, uncovering novel binding attributes of M1R-01 and detailed conformational epitope information. This work provides a promising candidate for the therapy and prophylaxis of orthopoxvirus infections.

Development and validation of a quantitative Orthopoxvirus immunoassay to evaluate and differentiate serological responses to Mpox infection and vaccination

BACKGROUND

The Mpox outbreak, caused by Monkeypox virus (MPXV), underscores the need for a serological assay to assess Mpox immunity. Modified Vaccinia Ankara (MVA) vaccine, an attenuated vaccinia virus (VACV), is authorised for Mpox prevention. We aimed to develop a quantitative immunoassay to differentiate infection- and vaccination-induced immunity and explore serological responses to Mpox infection and vaccination.

METHODS

We evaluated an electrochemiluminescence assay targeting IgG to 10 MPXV and 3 VACV antigens in plasma from adults in a cohort study with previous Mpox, MVA-vaccination, or historical controls. Sensitivity and specificity to distinguish i) seropositive versus naive and ii) infection- versus vaccination-induced seropositivity were determined using ROC curves. Antibody kinetics were analysed with generalised additive models.

FINDINGS

Eight of the thirteen IgG antibodies showed significant titre differences across groups identifying three key antigens: MPXVB6R, MPXVA27L, and VACVB5. A VACVB5 IgG titre of 0.082 IgG normalised units (nu) offered 74% (95% CI: 59-82%) sensitivity and 81% (73-96%) specificity for previous antigen exposure (infection or vaccine). For infection alone, an MPXVB6R IgG titre of 0.075 IgGnu provided 89% (82-98%) sensitivity and 94% (86-100%) specificity. To differentiate infection from vaccination-induced seropositivity, the sum of MPXVA27L IgG and the B6R/VACVB5 ratio provided 89% (80-96%) sensitivity and 80% (74-84%) specificity. VACVB5 IgG titres declined over time, with higher titres post-Mpox than post-vaccination (p < 0.0001).

INTERPRETATION

This assay demonstrates high sensitivity and specificity in quantifying and differentiating between antibody responses to Mpox infection and vaccination. Post-Mpox antibody responses were higher than post-vaccination, though both waned over time.

FUNDING

Health Research Board (MONKEYVAX-2022-1), University College Dublin School of Medicine.

Short-Lived Neutralizing Antibody Responses to Monkeypox Virus in Smallpox Vaccine-Naive Persons after JYNNEOS Vaccination

JYNNEOS, a third-generation smallpox vaccine, is integral to monkeypox virus (MPXV) control efforts, but the durability of this modified vaccinia Ankara-Bavarian Nordic (MVA-BN) vaccine's effectiveness is undefined. We optimized and used a plaque reduction neutralization test (PRNT) with authentic clade IIa MPXV and vaccinia virus to assess antibody responses over 12 months in 8 donors vaccinated with 2 doses of JYNNEOS. One donor previously received the ACAM2000 vaccine; 7 donors were smallpox vaccine-naive. IgG responses of the donors to vaccinia virus (L1, B5, and A33) or MPXV (E8, H3, A35) antigens and PRNT titers to both viruses peaked at 8 weeks postvaccination and waned rapidly thereafter in naive donors. MPXV PRNT titers were especially low; no naive donors demonstrated 90% plaque reduction. These data indicate a need for improved correlates of MPXV immunity to enable MVA-BN durability studies, given that recent clinical data support MVA-BN vaccine efficacy against MPXV despite low antibody responses.

Characterization and comparison of immunity against MPXV for individuals infected with MPXV or vaccinated with modified vaccinia Ankara vaccines

The 2022 Mpox virus (MPXV) outbreak revitalized questions about immunity against MPXV and vaccinia-based vaccines (VAC-V), but studies are limited. We analyzed immunity against MPXV in individuals infected with MPXV or vaccinated with the licensed modified vaccinia Ankara (MVA) Bavarian Nordic or an experimental MVA-HIVB vaccine. The frequency of neutralizing antibody responders was higher among MPXV-infected individuals than MVA vaccinees. Both MVA vaccines induced similar and strong humoral responses. Similarly, we show a higher frequency and magnitude (5-fold) of T cell responses, mainly mediated by CD8+ T cells, against a peptide pool containing selected sequences from MPXV, variola, and VAC-V in MPXV-infected individuals than MVA vaccinees. We describe a hierarchy of cross-reactive T cell responses against 5 peptide pools that are highly homologous between VAC-V and MPXV 2022, with the highest frequency of responders against MVA-121L and MVA-018L proteins. Both vaccines stimulated a notable frequency of polyfunctional CD4+ and CD8+ T cell responses, with a subset of CD4+ T cells showing a mixed cytokine profile. Finally, we found that smallpox vaccination in childhood positively affected humoral but not T cell vaccine responses, whereas these responses were not affected in people living with HIV. These findings contribute to deciphering and monitoring the profile of immunity to MPXV and MVA. In the context of a potential threat of the reemergence of smallpox following bioterrorism, the diversification and availability of potent vaccines is crucial. The comparable immunogenicity of both MVA vaccines emphasizes the potential utility of MVA-HIVB as a valuable new tool for controlling MPXV outbreaks.

Monkeypox: A comprehensive review on mutation, transmission, pathophysiology, and therapeutics

Monkeypox virus (MPXV) is the causative agent of the monkeypox (Mpox) disease, belongs to the Orthopoxvirus genus of the Poxviridae family. Due to the recent re-emergence of Mpox in 2024, this is the second time when the World Health Organization (WHO) declared Mpox as a Public Health Emergency of International Concern (PHEIC). This review intends to offer an in-depth analysis of Mpox, including its key characteristics, epidemiological, mutation, pathophysiology, transmission, and therapeutics. The infection of MPXV is a lethal threat to children, pregnant women, and immunocompromised individuals. However, we can prevent the infection by proper precautions including hygiene practices and minimizing exposure to infected individuals or animals. Multivalent mRNA vaccines, antibody-based immunotherapy, and combination drug therapies have all shown significant effectiveness in treating Mpox infection. In addition to addressing antivirals and drug resistance, the review also explores potential targets for vaccine and drug development, as well as the use of animal models for studying MPXV. Because of multiple mutational events, Mpox began exhibiting drug resistance. Overall, this review will contribute significantly to advancing the development of new vaccines and drug options for combating emerging Mpox.

Approaches to Next-Generation Capripoxvirus and Monkeypox Virus Vaccines

Globally, there are two major poxvirus outbreaks: mpox, caused by the monkeypox virus, and lumpy skin disease, caused by the lumpy skin disease virus. While vaccines for both diseases exist, there is a need for improved vaccines. The original vaccines used to eradicate smallpox, which also protect from the disease now known as mpox, are no longer acceptable. This is mainly due to the risk of serious adverse events, particularly in HIV-positive people. The next-generation vaccine for mpox prevention is modified vaccinia Ankara, which does not complete the viral replication cycle in humans and, therefore, has a better safety profile. However, two modified vaccinia Ankara immunizations are needed to give good but often incomplete protection, and there are indications that the immune response will wane over time. A better vaccine that induces a long-lived response with only one immunization is desirable. Another recently available smallpox vaccine is LC16m8. While LC16m8 contains replicating vaccinia virus, it is a more attenuated vaccine than the original vaccines and has limited side effects. The commonly used lumpy skin disease vaccines are based on attenuated lumpy skin disease virus. However, an inactivated or non-infectious vaccine is desirable as the disease spreads into new territories. This article reviews novel vaccine approaches, including mRNA and subunit vaccines, to protect from poxvirus infection.

Current advances and challenges in mpox vaccine development: a global landscape

Given the surge in mpox outbreaks in 2022 and the advancements in domestic and international vaccine research, the effectiveness of smallpox vaccines in providing cross-protection against mpox remains crucial. Having learned from the COVID-19 pandemic, it is significant to continue evaluating existing vaccines to ensure their safety and efficacy. Developing new vaccines for widespread use against mpox and its emerging strains also serves as a preventive strategy in the ongoing battle against this dynamic infection. Here's an opportunity to control human-to-human transmission, give short deadlines, and avoid vaccine disparity. Public health systems must take decisive action to prevent the global spread of mpox, particularly among vulnerable groups. This action should include strengthening global surveillance, improving vaccine access, and ensuring equitable distribution, particularly in resource-poor settings, to prevent future outbreaks. This review aims to assess recent advancements and barriers in mpox vaccine development, emphasizing cross-protection and equitable vaccine distribution in resource-poor settings.

Urogenital Manifestations in Mpox (Monkeypox) Infection: A Comprehensive Review of Epidemiology, Pathogenesis, and Therapeutic Approaches

Monkeypox (mpox), caused by mpox virus (MPXV) infection, reemerged in 2022 and still raises concerns globally. Abundant clinical data indicate that mpox is a sexually transmitted infection and that the urogenital system is the most frequently involved system in mpox, which deserves more attention. Penile lesions are the most common presentation, followed by urethritis. Acute urine retention and acute kidney injury are relatively rare but also highly crucial. Currently, the majority of the urogenital lesions are considered complications secondary to MPXV infection and the common immunosuppression in mpox patients. However, such viewpoints should be treated carefully due to the lack of understanding of the basic mpox pathology. Here, we briefly and comprehensively review the current evidence concerning urogenital lesions caused by mpox, including epidemiology, clinical features, pathogenesis, and therapeutic approaches to provide a preliminary reference for clinicians in future clinical practice.

Assessing healthcare workers’ knowledge and confidence in the diagnosis, management and prevention of Monkeypox

BACKGROUND

Monkeypox (Mpox), is a disease of global public health concern, as it does not affect only countries in western and central Africa.

AIM

To assess Burundi healthcare workers (HCWs)s’ level of knowledge and confidence in the diagnosis and management of Mpox.

METHODS

We conducted a cross-sectional study via an online survey designed mainly from the World Health Organization course distributed among Burundi HCWs from June-July 2023. The questionnaire comprises 8 socioprofessional-related questions, 22 questions about Mpox disease knowledge, and 3 questions to assess confidence in Mpox diagnosis and management. The data were analyzed via SPSS software version 25.0. A P value < 0.05 was considered to indicate statistical significance.

RESULTS

The study sample comprised 471 HCWs who were mainly medical doctors (63.9%) and nurses (30.1%). None of the 22 questions concerning Mpox knowledge had at least 50% correct responses. A very low number of HCWs (17.4%) knew that Mpox has a vaccine. The confidence level to diagnose (21.20%), treat (18.00%) or prevent (23.30%) Mpox was low among HCWs. The confidence level in the diagnosis of Mpox was associated with the HCWs’ age (P value = 0.009), sex (P value < 0.001), work experience (P value = 0.002), and residence (P value < 0.001). The confidence level to treat Mpox was significantly associated with the HCWs’ age (P value = 0.050), sex (P value < 0.001), education (P value = 0.033) and occupation (P value = 0.005). The confidence level to prevent Mpox was associated with the HCWs’ education (P value < 0.001), work experience (P value = 0.002), residence (P value < 0.001) and type of work institution (P value = 0.003).

CONCLUSION

This study revealed that HCWs have the lowest level of knowledge regarding Mpox and a lack of confidence in the ability to diagnose, treat or prevent it. There is an urgent need to organize continuing medical education programs on Mpox epidemiology and preparedness for Burundi HCWs. We encourage future researchers to assess potential hesitancy toward Mpox vaccination and its associated factors.

Long-Lasting Protection and Dose Optimization of MPXV Polyvalent Mpox mRNA Vaccines Against Lethal Vaccinia Virus Challenge in Mice

The outbreak of clade II monkeypox virus (MPXV) and the additional outbreak in Central Africa of clade I virus from 2023 have attracted worldwide attention. The development of a scalable and effective vaccine against the ongoing epidemic of mpox is urgently needed. We previously constructed two bivalent MPXV mRNA vaccines, LBA (B6R-A29L) and LAM (A35R-M1R), and a quadrivalent mRNA vaccine, LBAAM (B6R-A35R-A29L-M1R). These vaccines at a 20 µg dose could induce potential MPXV antigen-specific immune responses and provide protection against lethal VACV challenge. Compared with the individual bivalent mRNA vaccines, the two quadrivalent vaccines LBAAM and LBA& LAM displayed superior protective effects. To characterize these vaccines further, we monitored long-term immunity and protection as long as 28 weeks after initial immunization and optimized the immunization dosages to decrease the cost of production for future clinical use. Our results demonstrated that both the bivalent MPXV mRNA vaccine LAM (A35R-M1R) and the two tetravalent vaccines LBAAM and LBA& LAM could elicit long-lasting antigen-specific IgG antibodies as well as neutralizing antibodies against VACV and MPXV. They all provided complete protection against VACV challenge until 28 weeks post prime immunization. Moreover, the immunogenicity and protective efficacy of the two tetravalent vaccines (LBAAM and LBA& LAM) are dose dependent, and even the low-dose (1 µg) vaccine could provide sufficient protection against lethal VACV challenge. These results provide valuable clues for the further production of MPXV mRNA vaccines for use in humans.

Programmable Macrophage Vesicle Based Bionic Self-Adjuvanting Vaccine for Immunization against Monkeypox Virus

The emergence of monkeypox has become a global health threat after the COVID-19 pandemic. Due to the lack of available specifically treatment against MPV, developing an available vaccine is thus the most prospective and urgent strategy. Herein, a programmable macrophage vesicle based bionic self-adjuvanting vaccine (AM@AEvs-PB) is first developed for defending against monkeypox virus (MPV). Based on MPV-related antigen-stimulated macrophage-derived vesicles, the nanovaccine is constructed by loading the mature virion (MV)-related intracellular protein (A29L/M1R) and simultaneously modifying with the enveloped virion (EV) antigen (B6R), enabling them to effectively promote antigen presentation and enhance adaptive immune through self-adjuvant strategy. Owing to the synergistic properties of bionic vaccine coloaded MV and EV protein in defensing MPV, the activation ratio of antigen-presenting cells is nearly four times than that of single antigen in the same dose, resulting in stronger immunity in host. Notably, intramuscular injection uptake of AM@AEvs-PB demonstrated vigorous immune-protective effects in the mouse challenge attempt, offering a promising strategy for pre-clinical monkeypox vaccine development.

A pox on all our houses: a missing component in the global mpox response is equity

The global health community has had more than a decade to develop pandemic preparedness programmes and apply lessons learnt to new disease outbreaks. Mpox has now been declared a global public health emergency, but the response appears to be missing important elements of equity, focusing instead on diagnosis and surveillance. This approach leaves vulnerable populations in countries grappling with the outbreak without the preventive and treatment services they need. Based on our experiences managing the current mpox outbreak in Burundi, we outline some limitations of ongoing response strategies and advocate for the adoption of core principles that emphasise an equitable approach. These strategies include: community partnerships; care provided across the spectrum of disease; gender-informed services; sensitive community education; and promotion of community cohesion. Although funding and implementing these activities is ultimately the responsibility of governments, additional support might be needed also from non-governmental organisations, especially in settings characterised by conflict and fledgling health systems where the current mpox outbreak is centred.

Reactogenicity and Immunogenicity Against MPXV of the Intradermal Administration of Modified Vaccinia Ankara Compared to the Standard Subcutaneous Route

BACKGROUND

The recent resurgence of mpox in central Africa has been declared a new public health emergency of international concern (PHEIC) requiring coordinated international responses. Vaccination is a priority to expand protection and enhance control strategies, but the vaccine's need exceeds the currently available doses. Intradermal (ID) administration of one-fifth of the standard modified vaccinia Ankara (MVA-BN) dose was temporarily authorized during the 2022 PHEIC. Studies conducted before 2022 provided evidence about the humoral response against the vaccinia virus (VACV) after vaccination but not against the mpox virus (MPXV). Moreover, no data are available on the T-cell response elicited by MVA-BN administered subcutaneously or intradermally.

METHODS

We compare the two vaccine administration routes according to reactogenicity (n = 943) and immunogenicity (n = 225) of vaccine recipients attending INMI Spallanzani hospital during the 2022 vaccination campaign in Rome, Italy.

RESULTS

We found that the ID route elicited higher titers of MPXV-specific IgG (mean difference of 0.26 log2, p = 0.05) and nAbs (0.24 log2, p = 0.08) than the subcutaneous (SC) route one month after the complete vaccination cycle. At the same time, no evidence for a difference in cellular response was found.

CONCLUSIONS

MVA-BN was globally well tolerated despite higher reactogenicity for the ID than the SC route, especially for the reactions at the local injection site. The ID dose-sparing strategy was proven safe and immunogenic and would make vaccination available to more people. Our data support the current WHO recommendation of using the ID route in low-medium-income countries (LMIC), although response data in people infected with the new 1b clade are urgently needed.

Evaluation of a multiplexed immunoassay for assessing long-term humoral immunity Orthopoxviruses

BACKGROUND

The 2022 Monkeypox virus (MPXV) global outbreak boosted development of multiple serological assays to aid understanding of Mpox immunology.

OBJECTIVES

The study aimed to assess a multiplexed solid-phase electrochemiluminescence immunoassay (Meso Scale Discovery (MSD)) for simultaneous detection of antibodies against MPXV, including A35, E8 and M1 antigens, along with corresponding Vaccina Virus (VACV) homologues and demonstrate its accuracy in assessing antibody titres post-vaccination and infection.

METHODS

Assay performance was assessed for simultaneous detection of antibodies against MPXV and corresponding VACV antigens. Sensitivity and specificity were evaluated with paediatric negatives (n = 215), pre- and post-IMVANEX vaccinated (n = 80), and MPXV (Clade IIb, n = 39) infected serum samples.

RESULTS

The assay demonstrated high specificity (75.68 % (CI: 69.01-81.29) - 95.98 % (CI:92.54-97.87)) and sensitivity (62.11 % (CI:52.06-71.21) - 98.59 % (CI:92.44 %-99.93 %)) depending on the Orthopoxvirus antigen. Preferential binding was observed between MPXV-infected individuals and MPXV antigens, while vaccinated individuals exhibited increased binding to VACV antigens. These results highlight differential binding patterns between antigen homologues in related viruses.

CONCLUSION

Overall, this assay demonstrates high sensitivities in detecting antibodies for multiple relevant MPXV and VACV antigens post-infection and post-vaccination, indicating its utility in understanding immune responses to Orthopoxviruses in current and future outbreaks and evaluating the immunogenicity of new-generation Mpox-specific vaccinations.

MVA-BN vaccine effectiveness: A systematic review of real-world evidence in outbreak settings

BACKGROUND

Mpox is a disease endemic to Central and West Africa. It caused outbreaks in non-endemic countries, mainly in 2022. The endemic Democratic Republic of Congo is currently experiencing its largest outbreak yet. The vaccine Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN) is approved for active immunization against mpox and smallpox. Since the outbreak in 2022, real-world studies have assessed MVA-BN's vaccine effectiveness (VE) against mpox, and this systematic literature review aims to summarize the most current evidence.

METHODS

Medline (via PubMed), Embase, and LILACS were searched, as well as grey literature sources and publications' bibliographies to identify observational studies published between 1/Jan/2022 and 28/Feb/2024 that estimate the VE of MVA-BN against mpox or provide risk measures that allow calculation of these VE estimates. Data were presented descriptively in tables and text; the methodological quality of included records was assessed using NHLBI/NIH quality assessment tools.

RESULTS

The literature search identified 16 records that fit the inclusion criteria. The studies took place in high-income countries and were heterogeneous in design, setting, and definition of at-risk populations. MVA-BN VE estimates against mpox infection were assessed. Where the study population was exclusively or primarily those receiving pre-exposure prophylactic vaccination, the adjusted VE estimates ranged from 35 % to 86 % (n = 8 studies) for one dose and from 66 % to 90 % (n = 5) for two doses. Where only post-exposure prophylactic vaccination was assessed, adjusted VE estimates were reported for one dose only at 78 % and 89 % (n = 2). Additionally, MVA-BN reduced the risk of mpox-related hospitalization in one study and the severity of mpox clinical manifestations in two studies.

CONCLUSIONS

Despite heterogeneity in study design, setting, and at-risk populations, the reported VE estimates against mpox infection demonstrated the effectiveness of one or two doses of MVA-BN in the context of an outbreak across multiple countries.

Navigating monkeypox: identifying risks and implementing solutions

Monkeypox is a zoonotic disease caused by the orthopox virus, a double-stranded DNA virus that belongs the Poxviridae virus family. It is known to infect both animals (especially monkeys and rodents) and humans and causes a rash similar to smallpox. Humans can become infected with monkeypox virus (MPXV) when they get in close contact with infected animals (zoonotic transmission) or other infected people (human-human transmission) through their body fluids such as mucus, saliva, or even skin sores. Frequently observed symptoms of this disease include fever, headaches, muscle aches, and a rash that initially looks like a tiny bump before becoming a lump that is filled with fluid. Monkeypox symptoms also include an incubation period of 5-21 days, divided into prodromal and eruption phases. Several contributing factors, such as smallpox vaccine discontinuation, widespread intake of infected animal products as a source of protein, and high population density, amongst others, have been linked to an increase in the frequency of monkeypox outbreaks. The best course of action for diagnosing individuals who may be suffering from active monkeypox is to collect a sample of skin from the lesion and perform PCR molecular testing. Monkeypox does not presently have a specific therapy; however, supportive care can assist in managing symptoms, such as medication to lower body temperature and pain. Three major orthopoxvirus vaccines have been approved to serve as a preventive measure against monkeypox: LC16, JYNNEOS, and ACAM2000. The discovery that the monkeypox outbreak is communicable both among humans and within a population has sparked new public health worries on the possibility of the outbreak of another viral pandemic. Research and studies are still being conducted to gain a deeper understanding of this zoonotic viral disease. This review is therefore focused on deciphering monkeypox, its etiology, pathogenesis, transmission, risk factors, and control.

Mpox-Specific Immune Responses Elicited by Vaccination or Infection in People With HIV

In the recent mpox outbreak, people with human immunodeficiency virus (PWH) were at high risk both for contracting infection and for a more severe disease course. We studied cellular and humoral immune responses elicited by mpox infection (n = 5; n = 3 PWH) or smallpox vaccination (n = 17; all PWH) in a cohort of men who have sex with men. All PWH were successfully treated, with stable CD4 counts and undetectable HIV viral loads. Eleven of 17 vaccinated individuals had received childhood smallpox vaccination. In this group of individuals, both 2-dose modified vaccinia Ankara (MVA) vaccination and natural infection evoked mpox-specific immune responses mediated by B cells as well as CD4 and CD8 T cells. This study improves our understanding of smallpox vaccination-mediated cross-reactivity to other orthopox viruses, and long-lasting durability of childhood smallpox vaccination-mediated immune responses, including in PWH.

Comparison of Waning Antibody Responses After Natural Monkeypox Virus Infection and Mpox Vaccination Beyond 6 Months in South Korea

Natural Monkeypox virus infection induced significantly higher neutralizing antibody titers than Jynneos vaccination, with similar antibody decay rates beyond 6 months. Jynneos recipients with prior smallpox vaccination showed antibody levels comparable to mpox convalescents.

The monkeypox virus-host interplays

Monkeypox virus (MPXV) is a DNA virus belonging to the Orthopoxvirus genus within the Poxviridae family which can cause a zoonotic infection. The unexpected non-endemic outbreak of mpox in 2022 is considered as a new global threat. It is imperative to take proactive measures, including enhancing our understanding of MPXV's biology and pathogenesis, and developing novel antiviral strategies. The host immune responses play critical roles in defensing against MPXV infection while the virus has also evolved multiple strategies for immune escape. This review summarizes the biological features, antiviral immunity, immune evasion mechanisms, pathogenicity, and prevention strategies for MPXV.

Multi-organ clinical manifestations of Mpox: an umbrella review of systematic reviews

BACKGROUND

Mpox is a severe viral zoonosis that has emerged as a public health concern due to its potential for human-to-human transmission and severe illness. Understanding its clinical manifestations is crucial for effective management and control. Several systematic reviews have assessed various manifestations of Mpox. This umbrella review synthesizes evidence on Mpox's manifestations across different organ systems.

METHOD

We conducted an umbrella review, adhering to Joanna Briggs Institute (JBI) methodology and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, focusing on systematic reviews of Mpox manifestations. We performed a literature search up to 25th September 2023, in databases like PubMed, Embase, and Web of Science. We included systematic reviews of observational studies, case reports, case series, or RCTs reporting any manifestations of Mpox in humans, focusing on a global scope. AMSTAR 2 was used to evaluate the quality of systematic reviews, and data has been synthesized in narrative and tabular manners.

RESULTS

A total of 25 systematic reviews were included, uncovering diverse manifestations of Mpox, such as cutaneous, cardiovascular, oral, ophthalmic, gastrointestinal, respiratory, and pregnancy-related. Cutaneous manifestations (up to 100%) were the most prevalent, featuring lesions and rashes. Constitutional symptoms of viral illness were reported in ~ 60% to > 85% of the cases. Significant respiratory symptoms were present in ~ 50% of cases overall. Headaches were the leading neurological symptom present in > 30%. Symptoms of gastrointestinal involvement ranged from 39% (oral lesions) with decreasing frequency to low diarrhea at ~ 5%, with proctitis percentages ranging from high teens to mid-twenties. Ophthalmic manifestations (6% but with wide variations among studies). Many primary studies included in the systematic reviews consisted of case reports and case series. A wide range of manifestations across different organ systems was observed. Negative outcomes for pregnancies were reported, but evidence is limited. Adverse cardiovascular and neurological outcomes were identified, though only a few studies provided insights into these findings.

CONCLUSION

Mpox exhibits diverse manifestations, impacting multiple organ systems, with substantial variations. The findings highlight the importance of ongoing, nuanced, and region-specific research and management strategies for Mpox. The reliance on case reports and series underscores the need for more high-quality, long-term studies to deepen our understanding and management of this significant public health concern.

Rational design and computational evaluation of a multi-epitope vaccine for monkeypox virus: Insights into binding stability and immunological memory

Multi-epitope vaccines strategically tackle rapidly mutating viruses by targeting diverse epitopes from different proteins, providing a comprehensive and adaptable immune protection approach for enhanced coverage against various viral variants. This research employs a comprehensive approach that includes the mapping of immune cells activating epitopes derived from the six structural glycoproteins (A29L, A30L, A35R, L1R, M1R, and E8L) of Monkeypox virus (Mpox). A total of 7 T-cells-specific epitopes, 13 B-cells-specific epitopes, and 5 IFN-γ activating epitopes were forecasted within these glycoproteins. The selection process focused on epitopes indicating high immunogenicity and favorable binding affinity with multiple MHC alleles. Following this, a vaccine has been formulated by incorporating the chosen epitopes, alongside adjuvants (PADRE peptide) and various linkers (EAAAK, GPGPG, and AAY). The physicochemical properties and 3D structure of the multi-epitope hybrid vaccine were analysed for characterization. MD simulations were employed to predict the binding stability between the vaccine and various pathogen recognition receptors such as TLRs (TLR1, TLR2, TLR4, and TLR6), as well as both class I and II MHC, achieved through hydrogen bonding and hydrophobic interactions. Through in silico cloning and immune simulation, it was observed that the multi-epitopes vaccine induced a robust memory immune response upon booster doses, forecasting protective immunity upon viral challenge. This protective immunity was characterized by the production of IgM + IgG antibodies, along with release of inflammatory cytokines like IFN-γ, and IL12, and the activation of various immune cells. This study offers valuable insights into the potential of a multi-epitope vaccine targeting the Mpox virus.

Characterization of the Monkeypox Virus [MPX]-Specific Immune Response in MPX-Cured Individuals Using Whole Blood to Monitor Memory Response

BACKGROUND

Monkeypox (Mpox) is a zoonotic disease caused by monkeypox virus (MPXV), an Orthopoxvirus (OPXV). Since we are observing the first MPXV outbreak outside the African continent, the general population probably does not have a pre-existing memory response for MPXV but may have immunity against the previous smallpox vaccine based on a live replicating Vaccinia strain (VACV). Using a whole blood platform, we aim to study the MPXV- T-cell-specific response in Mpox-cured subjects.

METHODS

We enrolled 16 subjects diagnosed with Mpox in the previous 3-7 months and 15 healthy donors (HD) with no recent vaccination history. Whole blood was stimulated overnight with MPXV and VACV peptides to elicit CD4 and CD8 T-cell-specific responses, which were evaluated by ELISA and multiplex assay.

RESULTS

Mpox-cured subjects showed a significant IFN-γ T-cell response to MPXV and VACV. Besides IFN-γ, IL-6, IP-10, IL-8, IL-2, G-CSF, MCP-1, MIP1-α, MIP-1β, IL-1Rα, and IL-5 were significantly induced after specific stimulation compared to the unstimulated control. The specific response was mainly induced by the CD4 peptides MPX-CD4-E and VACV-CD4.

CONCLUSIONS

We showed that MPXV-specific responses have a mixed Th1- and Th2-response in a whole blood platform assay, which may be useful for monitoring the specific immunity induced by vaccination or infection.

Immune responses associated with mpox viral clearance in men with and without HIV in Spain: a multisite, observational, prospective cohort study

BACKGROUND

Since the emergence of the global mpox outbreak in May, 2022, more than 90 000 cases have been diagnosed across 110 countries, disproportionately affecting people with HIV. The durability of mpox-specific immunity is unclear and reinfections have been reported. We aimed to compare mpox immune responses up to 6 months after diagnosis in participants with and without HIV and assess their effect on disease severity and viral clearance dynamics.

METHODS

This study was embedded within a prospective, observational, multicentre cohort study of viral clearance dynamics among people with mpox in Spain (MoViE). We included women and men aged 18 years or older, who had signs of mpox, and reported having symptom onset within the previous 10 days at the moment of mpox diagnosis from three sex clinics of the Barcelona metropolitan area. Samples from skin ulcers were collected weekly to estimate the time to clear monkeypox virus (MPXV) from skin lesions. Blood samples were taken at diagnosis, 29, 91, and 182 days later for immune analysis. This included quantifying IgG and IgA against three mpox antigens by ELISA, evaluating in-vitro neutralisation, and characterising mpox-specific T-cell responses using interferon γ detecting enzyme-linked immunospot (ELISpot) assay and multiparametric flow cytometry.

FINDINGS

Of the 77 originally enrolled participants, we included 33 participants recruited between July 19, and Oct 6, 2022. Participants without HIV (19 [58%] participants) and participants with HIV (14 [42%] participants) had similar clinical severity and time to MPXV clearance in skin lesions. Participants with HIV had a CD4+ T-cell count median of 777 cells per μL (IQR 484-1533), and 11 (78%) of 14 were virally suppressed on antiretroviral therapy. Nine (27%) of 33 participants were age 49 years or older. 15 (45%) of 33 participants were originally from Spain, and all participants were men. Early humoral responses, particularly concentrations and breadth of IgG and IgA, were associated with milder disease and faster viral clearance. Orthopoxvirus-specific T cells count was also positively correlated with MPXV clearance. Antibody titres declined more rapidly in participants with HIV, but T-cell responses against MPXV were sustained up to day 182 after diagnosis, regardless of HIV status.

INTERPRETATION

Higher breadth and magnitude of B-cell and T-cell responses are important in facilitating local viral clearance, limiting mpox dissemination, and reducing disease severity in individuals with preserved immune system. Antibodies appear to contribute to early viral control and T-cell responses are sustained over time, which might contribute to milder presentations during reinfection.

FUNDING

Fundació Lluita contra les Infeccions, IrsiCaixa, and Consorcio Centro de Investigación Biomédica en Red, Instituto de Salud Carlos III, Ministerio de Ciencia, Innovación e Universidades.

Profiling of viral load, antibody and inflammatory response of people with monkeypox during hospitalization: a prospective longitudinal cohort study in China

BACKGROUND

The dynamics of viral shedding and the specific humoral response against monkeypox virus (MPXV) have not been well characterized in patients across their disease course during hospitalisation. The aim of this study was to determine the viral load and the levels of antibodies against MPXV using longitudinal paired-collected samples from hospitalized patients.

METHODS

Patients who were hospitalised with mpox were recruited at Beijing Ditan Hospital Capital Medical University in China between June 2 and September 23, 2023. Paired samples, including samples from skin lesions, the oropharynx, saliva, faeces, urine, plasma, and serum, were serially collected at days 1, 3, 7, and 14 after admission until discharge. Not all of the patients had samples obtained at all of the timepoints. All the samples were analysed via quantitative PCR. Virus isolation was performed by using clinical samples and Vero cells. The presence of IgM, IgA, IgG, and neutralising antibodies (NAbs) against MPXV was evaluated. The first collected plasma sample was taken when the patient was hospitalised, and the levels of cytokines and chemokines were measured in the sample. The demographic data, smallpox vaccination status, history of known exposure to MPVX, HIV status and other clinical data were collected using a standard case report form.

FINDINGS

A total of 510 specimens were serially collected from 39 recruited people with mpox. Among all the samples, the skin lesions had the highest viral DNA detection rates and viral loads, and the saliva samples had the second highest rates and viral loads. One day before discharge, 85% of the dry scrabs (median Ct 28.2, range 19.0-38.3) and 70% of the saliva samples (median Ct 32.4, range 24.5-38.1) were positive for viral DNA, Of which, 23.1% of dry scrabs were positive in viral culture. The rate of viral DNA detection in the oropharyngeal, saliva, and faecal samples decreased with time, while the rates in the plasma, serum, and urine samples increased quickly before 10 days post symptom onset (PSO). The median days of appearance of MPXV-IgM, MPXV-IgA, MPXV-IgG, and NAb were at 8 (interquartile range [IQR] 7-9), 9 (7-10), 12 (9-15), and 12 (9-15) PSO, respectively. The IgM, IgA, IgG, and NAb titres increased with time. Between days 11 and 21 PSO, the NAb titres were lower in people living with HIV (PWH) than in people living without HIV (PWOH). Increased NAb titres were associated with decreased viral loads in the saliva (r = 0.28, p = 0.025), faeces (r = 0.35, p = 0.021), plasma (r = 0.30, p = 0.0044), and serum samples (r = 0.37, p = 0.001). Compared with PWOH, PWH had higher plasma levels of MIP-1α, MIP-1β, G-CSF, IL-4, and FGF-basic.

INTERPRETATION

The high positive viral culture rate of clinical samples of patients when they are discharged from the hospital indicates that effective public health management strategies are needed for people with mpox. The low NAb titres and high levels of cytokines in PWH shows that earlier treatment is needed to control inflammation in high-risk populations.

FUNDING

National Natural Science Foundation of China, Chinese Academy of Medical Sciences, Fundamental Research Funds for the Central Universities for Peking Union Medical College, National Key R&D Program of China.

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.

Enhanced Immune Responses in Mice by Combining the Mpox Virus B6R-Protein and Aluminum Hydroxide-CpG Vaccine Adjuvants

Novel adjuvants and innovative combinations of adjuvants (Adjuvant Systems) have facilitated the development of enhanced and new vaccines against re-emerging and challenging pathogenic microorganisms. Nonetheless, the efficacy of adjuvants is influenced by various factors, and the same adjuvant may generate entirely different immune responses when paired with different antigens. Herein, we combined the MPXV-B6R antigen with BC02, a novel adjuvant with proprietary technology, to assess its capability to induce both cellular and humoral immunity in mouse models. Mice received two intramuscular injections of B6R-BC02, which resulted in the production of MPXV-specific IgG, IgG1, and IgG2a antibodies. Additionally, it elicited strong MPXV-specific Th1-oriented cellular immunity and persistent effector memory B-cell responses. The advantages of BC02 were further validated, including rapid initiation of the immune response, robust recall memory, and sustained immune response induction. Although the potential of immunized mice to produce serum-neutralizing antibodies against the vaccinia virus requires further improvement, the exceptional performance of BC02 as an adjuvant for the MPXV-B6R antigen has been consistently demonstrated.

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.

Third-generation smallpox vaccines induce low-level cross-protecting neutralizing antibodies against Monkeypox virus in laboratory workers

Due to the discontinuation of routine smallpox vaccination after its eradication in 1980, a large part of the human population remains naïve against smallpox and other members of the orthopoxvirus genus. As a part of biosafety personnel protection programs, laboratory workers receive prophylactic vaccinations against diverse infectious agents, including smallpox. Here, we studied the levels of cross-protecting neutralizing antibodies as well as total IgG induced by either first- or third-generation smallpox vaccines against Monkeypox virus, using a clinical isolate from the 2022 outbreak. Serum neutralization tests indicated better overall neutralization capacity after vaccination with first-generation smallpox vaccines, compared to an attenuated third-generation vaccine. Results obtained from total IgG ELISA, however, did not show higher induction of orthopoxvirus-specific IgGs in first-generation vaccine recipients. Taken together, our results indicate a lower level of cross-protecting neutralizing antibodies against Monkeypox virus in recipients of third-generation smallpox vaccine compared to first-generation vaccine recipients, although total IgG levels were comparable.

Longitudinal viral shedding and antibody response characteristics of men with acute infection of monkeypox virus: a prospective cohort study

Understanding of infection dynamics is important for public health measures against monkeypox virus (MPXV) infection. Herein, samples from multiple body sites and environmental fomites of 77 acute MPXV infections (HIV co-infection: N = 42) were collected every two to three days and used for detection of MPXV DNA, surface protein specific antibodies and neutralizing titers. Skin lesions show 100% positivity rate of MPXV DNA, followed by rectum (88.16%), saliva (83.78%) and oropharynx (78.95%). Positivity rate of oropharynx decreases rapidly after 7 days post symptom onset (d.p.o), while the rectum and saliva maintain a positivity rate similar to skin lesions. Viral dynamics are similar among skin lesions, saliva and oropharynx, with a peak at about 6 d.p.o. In contrast, viral levels in the rectum peak at the beginning of symptom onset and decrease rapidly thereafter. 52.66% of environmental fomite swabs are positive for MPXV DNA, with highest positivity rate (69.89%) from air-conditioning air outlets. High seropositivity against A29L (100%) and H3L (94.74%) are detected, while a correlation between IgG endpoint titers and neutralizing titers is only found for A29L. Most indexes are similar between HIV and Non-HIV participants, while HIV and rectitis are associated with higher viral loads in rectum.

CGO-ensemble: Chaos game optimization algorithm-based fusion of deep neural networks for accurate Mpox detection

The rising global incidence of human Mpox cases necessitates prompt and accurate identification for effective disease control. Previous studies have predominantly delved into traditional ensemble methods for detection, we introduce a novel approach by leveraging a metaheuristic-based ensemble framework. In this research, we present an innovative CGO-Ensemble framework designed to elevate the accuracy of detecting Mpox infection in patients. Initially, we employ five transfer learning base models that integrate feature integration layers and residual blocks. These components play a crucial role in capturing significant features from the skin images, thereby enhancing the models' efficacy. In the next step, we employ a weighted averaging scheme to consolidate predictions generated by distinct models. To achieve the optimal allocation of weights for each base model in the ensemble process, we leverage the Chaos Game Optimization (CGO) algorithm. This strategic weight assignment enhances classification outcomes considerably, surpassing the performance of randomly assigned weights. Implementing this approach yields notably enhanced prediction accuracy compared to using individual models. We evaluate the effectiveness of our proposed approach through comprehensive experiments conducted on two widely recognized benchmark datasets: the Mpox Skin Lesion Dataset (MSLD) and the Mpox Skin Image Dataset (MSID). To gain insights into the decision-making process of the base models, we have performed Gradient Class Activation Mapping (Grad-CAM) analysis. The experimental results showcase the outstanding performance of the CGO-ensemble, achieving an impressive accuracy of 100% on MSLD and 94.16% on MSID. Our approach significantly outperforms other state-of-the-art optimization algorithms, traditional ensemble methods, and existing techniques in the context of Mpox detection on these datasets. These findings underscore the effectiveness and superiority of the CGO-Ensemble in accurately identifying Mpox cases, highlighting its potential in disease detection and classification.

A Case of Varicella Zoster and Mpox Coinfection in a Patient Living With HIV

ABSTRACT

We present a case of recurrent, cutaneous mpox with coinfection of disseminated varicella zoster in an immunocompromised patient with poorly controlled HIV. This case demonstrates the importance of maintaining a high index of suspicion for mpox despite prior infection and vaccination, as suboptimal immune response is possible in immunocompromised patients, and also noting the potential for coinfection necessitating timely diagnosis and appropriate testing.

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".

nf-core/airrflow: an adaptive immune receptor repertoire analysis workflow employing the Immcantation framework

Adaptive Immune Receptor Repertoire sequencing (AIRR-seq) is a valuable experimental tool to study the immune state in health and following immune challenges such as infectious diseases, (auto)immune diseases, and cancer. Several tools have been developed to reconstruct B cell and T cell receptor sequences from AIRR-seq data and infer B and T cell clonal relationships. However, currently available tools offer limited parallelization across samples, scalability or portability to high-performance computing infrastructures. To address this need, we developed nf-core/airrflow, an end-to-end bulk and single-cell AIRR-seq processing workflow which integrates the Immcantation Framework following BCR and TCR sequencing data analysis best practices. The Immcantation Framework is a comprehensive toolset, which allows the processing of bulk and single-cell AIRR-seq data from raw read processing to clonal inference. nf-core/airrflow is written in Nextflow and is part of the nf-core project, which collects community contributed and curated Nextflow workflows for a wide variety of analysis tasks. We assessed the performance of nf-core/airrflow on simulated sequencing data with sequencing errors and show example results with real datasets. To demonstrate the applicability of nf-core/airrflow to the high-throughput processing of large AIRR-seq datasets, we validated and extended previously reported findings of convergent antibody responses to SARS-CoV-2 by analyzing 97 COVID-19 infected individuals and 99 healthy controls, including a mixture of bulk and single-cell sequencing datasets. Using this dataset, we extended the convergence findings to 20 additional subjects, highlighting the applicability of nf-core/airrflow to validate findings in small in-house cohorts with reanalysis of large publicly available AIRR datasets. nf-core/airrflow is available free of charge, under the MIT license on GitHub (https://github.com/nf-core/airrflow). Detailed documentation and example results are available on the nf-core website at (https://nf-co.re/airrflow).

Mpox (formerly monkeypox): pathogenesis, prevention, and treatment

In 2022, a global outbreak of Mpox (formerly monkeypox) occurred in various countries across Europe and America and rapidly spread to more than 100 countries and regions. The World Health Organization declared the outbreak to be a public health emergency of international concern due to the rapid spread of the Mpox virus. Consequently, nations intensified their efforts to explore treatment strategies aimed at combating the infection and its dissemination. Nevertheless, the available therapeutic options for Mpox virus infection remain limited. So far, only a few numbers of antiviral compounds have been approved by regulatory authorities. Given the high mutability of the Mpox virus, certain mutant strains have shown resistance to existing pharmaceutical interventions. This highlights the urgent need to develop novel antiviral drugs that can combat both drug resistance and the potential threat of bioterrorism. Currently, there is a lack of comprehensive literature on the pathophysiology and treatment of Mpox. To address this issue, we conducted a review covering the physiological and pathological processes of Mpox infection, summarizing the latest progress of anti-Mpox drugs. Our analysis encompasses approved drugs currently employed in clinical settings, as well as newly identified small-molecule compounds and antibody drugs displaying potential antiviral efficacy against Mpox. Furthermore, we have gained valuable insights from the process of Mpox drug development, including strategies for repurposing drugs, the discovery of drug targets driven by artificial intelligence, and preclinical drug development. The purpose of this review is to provide readers with a comprehensive overview of the current knowledge on Mpox.

Neutralization Determinants on Poxviruses

Smallpox was a highly contagious disease caused by the variola virus. The disease affected millions of people over thousands of years and variola virus ranked as one of the deadliest viruses in human history. The complete eradication of smallpox in 1980, a major triumph in medicine, was achieved through a global vaccination campaign using a less virulent poxvirus, vaccinia virus. Despite this success, the herd immunity established by this campaign has significantly waned, and concerns are rising about the potential reintroduction of variola virus as a biological weapon or the emergence of zoonotic poxviruses. These fears were further fueled in 2022 by a global outbreak of monkeypox virus (mpox), which spread to over 100 countries, thereby boosting interest in developing new vaccines using molecular approaches. However, poxviruses are complex and creating modern vaccines against them is challenging. This review focuses on the structural biology of the six major neutralization determinants on poxviruses (D8, H3, A27, L1, B5, and A33), the localization of epitopes targeted by neutralizing antibodies, and their application in the development of subunit vaccines.

Comparative Epidemiological Assessment of Monkeypox Infections on a Global and Continental Scale Using Logistic and Gompertz Mathematical Models

The monkeypox virus (MPXV) has caused an unusual epidemiological scenario-an epidemic within a pandemic (COVID-19). Despite the inherent evolutionary and adaptive capacity of poxviruses, one of the potential triggers for the emergence of this epidemic was the change in the status of orthopoxvirus vaccination and eradication programs. This epidemic outbreak of HMPX spread worldwide, with a notable frequency in Europe, North America, and South America. Due to these particularities, the objective of the present study was to assess and compare cases of HMPX in these geographical regions through logistic and Gompertz mathematical modeling over one year since its inception. We estimated the highest contagion rates (people per day) of 690, 230, 278, and 206 for the world, Europe, North America, and South America, respectively, in the logistic model. The equivalent values for the Gompertz model were 696, 268, 308, and 202 for the highest contagion rates. The Kruskal-Wallis Test indicated different means among the geographical regions affected by HMPX regarding case velocity, and the Wilcoxon pairwise test indicated the absence of significant differences between the case velocity means between Europe and South America. The coefficient of determination (R2) values in the logistic model varied from 0.8720 to 0.9023, and in the Gompertz model, they ranged from 0.9881 to 0.9988, indicating a better fit to the actual data when using the Gompertz model. The estimated basic reproduction numbers (R0) were more consistent in the logistic model, varying from 1.71 to 1.94 in the graphical method and from 1.75 to 1.95 in the analytical method. The comparative assessment of these mathematical modeling approaches permitted the establishment of the Gompertz model as the better-fitting model for the data and the logistic model for the R0. However, both models successfully represented the actual HMPX case data. The present study estimated relevant epidemiological data to understand better the geographic similarities and differences in the dynamics of HMPX.

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.