Comparison of lyophilized versus liquid modified vaccinia Ankara (MVA) formulations and subcutaneous versus intradermal routes of administration in healthy vaccinia-naïve subjects

Differences in Mpox and Vaccinia Immunity Induced by Non-Replicating and Replicating Vaccinia-Based Vaccines

Background: The recent global outbreak with clade IIb and the concurrent emergence of clade I mpox virus in Africa show that mpox is a challenging problem. MVA-BN induces low-level mpox-neutralizing antibody responses that wane rapidly. This study was conducted to compare the mpox immunity induced by a replication-competent smallpox vaccine and non-replicating MVA-BN. Methods: Stored sera (n = 302) and PBMCs (n = 244) collected pre-vaccination and at five post-vaccination time points in MVA-BN and six post-vaccination time points in Dryvax clinical trials were used. Antibody titers that neutralized at least 50% of mpox in cell culture were determined by the focus reduction neutralization test (FRNT) 50, and the mpox-specific T cell responses were measured using an IFN-γ ELISPOT assay. Results: The peak geometric fold rise (95% CI) (i.e., the maximum GMFR across all study visits) in the mpox FRNT50 for subcutaneous (SC) MVA-BN, intradermal (ID) MVA-BN, and Dryvax was 22.1 (8.3, 59.1), 18.5 (8.0, 43.1), and 245.8 (100.4, 601.6), respectively. The GMFR at day 180 post-vaccination for MVA-BN (SC), MVA-BN (ID), and Dryvax was 2.4, 2.7, and 64, respectively. The mean (95% CI) peak number of mpox-specific IFN-γ-producing SFCs was 127 (43.1, 238.3), 87.3 (46, 137), and 61.2 (44.3, 77.7) for MVA-BN (SC), MVA-BN (ID), and Dryvax, respectively. On day 180, the mean SFCs in the three groups decreased to 10.8 (-34.4, 3.8), 3.3 (-6.2, 18.6), and 2.2 (-9, 12.5), respectively. Conclusions: The peak mpox-neutralizing antibody titer was >10-fold lower in MVA-BN recipients compared to those who received a replication-competent smallpox vaccine, and the level at day 180 was >20 times lower in MVA-BN recipients. MVA-BN induced similar or higher T cell responses.

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.

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.

Next-Generation SARS-CoV-2 Vaccine Formulations and Alternative Routes of Administration

The development of SARS-CoV-2 next-generation vaccines with the potential for increased effectiveness, durability, breadth, and ability to decrease transmission are of public health importance. We highlight alternative routes of administration of next-generation SARS-CoV-2 vaccines such as mucosal and intradermal administration.

Mpox treatment evolution: past milestones, present advances, and future directions

An underestimated worldwide health concern, Monkeypox (Mpox) is becoming a bigger menace to the world's population. After smallpox was eradicated in 1970, Mpox was found in a rural region of Africa and quickly spread to other African countries. The etiological agent of the Mpox infection, the Mpox virus, is constantly evolving, and its capability for cross-species transmission led to a global outbreak in 2022 which led to several deaths throughout the world. This review aims to showcase the progressive treatment methods and emerging innovations in the diagnostic and prevention strategies for controlling Mpox. The clinical trial data for antiviral drugs were systematically collected and analyzed using statistical tests to determine the most effective antiviral treatment. Emerging viral protein inhibitors that are under investigation for Mpox treatment were also scrutinized in this review. Additionally, modern diagnostic methods, such as the Streamlined CRISPR On Pod Evaluation platform (SCOPE) and graphene quantum rods were reviewed, and the efficacy of mRNA vaccines with traditional smallpox vaccines used for Mpox were compared. The statistical analysis revealed that tecovirimat (TCV) is the most effective antiviral drug among the other evaluated drugs, showing superior efficacy in clinical trials. Similarly, mRNA vaccines offer greater effectiveness compared to conventional smallpox vaccines. Furthermore, emerging nanomedicine and herbal drug candidates were highlighted as potential future treatments for Mpox. The findings underscore the effectiveness of TCV in treating Mpox and highlight significant advancements in preventive treatments. The review also points to innovative approaches in vaccine technology and potential future therapies, including nanomedicine and herbal remedies, which may enhance Mpox management.

Optimizing Microneutralization and IFN-γ ELISPOT Assays to Evaluate Mpox Immunity

BACKGROUND

Available assays to measure pox virus neutralizing antibody titers are laborious and take up to 5 days. In addition, assays to measure T cell responses require the use of specific antigens, which may not be the same for all pox viruses. This study reports the development of robust assays for the measurement of mpox-specific neutralizing antibodies and IFN-γ-producing T-cell responses.

METHODS

Fourteen samples from 7 volunteers who received Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN) were used. The focused reduction neutralization test (FRNT) was performed using the mpox-specific A29 monoclonal antibody. Optimization and further development of FRNT were conducted using the plaque reduction neutralization test (PRNT) as the gold standard. The mpox-specific IFN-γ ELISPOT assay was optimized using different mpox antigen preparations. Results with pre-vaccination samples were compared with post-vaccination samples using the Wilcoxon matched-pairs test.

RESULTS

Pre-vaccination and post-vaccination sera (n = 7) had FRNT50 (i.e., titers that inhibited at least 50% of the virus) of 109.1 ± 161.8 and 303.7 ± 402.8 (mean ± SD), respectively. Regression analysis of fold changes in FRNT50 and PRNT50 showed that the two assays closely agree (n = 25 tests on paired samples, R2 of 0.787). Using UV-inactivated mpox as an antigen, the number of IFN-γ spot-forming T cells (SFC) in pre-vaccination samples (16.13 ± 15.86, mean ± SD) was significantly lower than SFC in post-vaccination samples (172.9 ± 313.3, mean ± SD) with p = 0.0078.

CONCLUSIONS

Our newly developed microneutralization test has a good correlation with PRNT. UV-inactivated mpox is an appropriate antigen for the ELISPOT assay that measures mpox cross-reactive T cells. These assays will be useful in future mpox vaccine studies.

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

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

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.

Stigmatization and Preferences in Monkeypox Vaccine Regimens

A significant monkeypox (mpox) outbreak occurred in 2022, particularly involving sexual and gender minority (SGM) groups. Stigma and misperceptions have led to fear of being labeled a member of the SGM group when obtaining immunization for mpox. We hypothesized that the most recommended injection site, intradermal injection in the forearm, stresses stigmatization. We conducted an online survey in a medical center in Taiwan between May 2023 and June 2023 among adults who were going to receive the second preexposure vaccination. The questionnaire comprised questions about physical and psychological impacts of the first mpox vaccination and the preference for the second vaccination location and factors influencing the preference. A total of 2,827 individuals (98.4% male) completed the questionnaires. Intradermal injection in the forearm was related to greater physical and psychological impacts of local adverse events, especially discoloration. "Beauty," "scar," and "others' view" were the most significant factors influencing preference for vaccination regimens. Compared to intradermal injection in the forearm, subjects who cared about "others' views" were likely to prefer vaccination in the deltoid. The odds ratio for preferring intradermally injection in the deltoid over in the forearm was 1.88 (95% CI 1.38-2.56). The odds ratio for preferring subcutaneous injection in the deltoid over intradermally injection in the forearm was 1.69 (95% CI 1.23-2.32). The odds ratio for preferring intradermally injection in the deltoid regardless of the route over intradermally injection in the forearm was 2.11 (95% CI 1.53-2.92). This study demonstrated the adverse events of different mpox vaccination regimens and their association with stigma. Recognizing the factors affecting the preference for mpox vaccine regimens is crucial for easing the mental stress of vaccinee.

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.

Mpox: what sexual health physicians need to know?

Monkeypox virus (MPXV) is another zoonotic virus spilled over to the man and resulted in pandemic. World Health Organization declared it as a 'Public Health Emergency of International Concern (PHEIC) on July 22, 2022. Mpox affected over 95226 individuals among them claimed the lives of 185. Despite the fact that Mpox is generally mild and self-limited, immunocompromised people with low CD4 counts may experience severe disease course. Management of Mpox patients has three pillars. First symptomatic approach includes pain management, prophylaxis for secondary infections and when needed effective treatment of superinfections. Second, vaccines developed against smallpox can be used in preexposure or postexposure prophylaxis strategies against Mpox. Third, current antiviral options include tecovirimat, cidofovir and birincidofovir all of which have been recommended relying on experience from animal studies, clinical case reports or case series. Results of well-planned randomized control trials are not available. Occupational exposure to MPXV is especially a manageable risk for health care workers. Prevention of Mpox also requires risk communication with vulnerable population and their involvement in mitigation efforts.

JYNNEOS Vaccine Safety Surveillance During the 2022 Mpox Outbreak Using the Vaccine Adverse Event Reporting System and V-safe, United States, 2022 to 2023

BACKGROUND

In response to the 2022 mpox outbreak in the United States, people with higher potential for exposure to mpox were recommended to receive 2 doses of the JYNNEOS vaccine. Vaccine safety was monitored using 2 complementary systems.

METHODS

The Vaccine Adverse Event Reporting System (VAERS) is a passive surveillance system that accepts reports of adverse events after vaccination. VAERS is capable of rapidly identifying rare adverse events and unusual reporting patterns. Medical records were requested and reviewed for adverse events of special interest, including myocarditis. Adverse event reporting rates were calculated as the number of verified adverse event cases divided by the number of JYNNEOS doses administered. V-safe for mpox was a voluntary smartphone-based vaccine safety surveillance system that sent enrolled persons text messages linked to health surveys asking about reactions and health impact events occurring after vaccination.

RESULTS

There were 1,207,056 JYNNEOS doses administered in the United States. VAERS received 1927 reports for JYNNEOS. The myocarditis reporting rate per million doses was 2.69 after dose 1 and 8.64 after dose 2. V-safe had 213 participants complete at least one health survey. Rates of injection site and systemic reactions were similar in the first week after dose 1 and dose 2.

CONCLUSIONS

JYNNEOS vaccine safety surveillance findings from VAERS and v-safe did not identify any unexpected safety concerns. The VAERS reporting rate for myocarditis was similar to previously published population background rates.

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.

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.

Cross-Country Discrepancies in Monkeypox Vaccine Hesitancy Among Postgraduate and Undergraduate Medical Students

BACKGROUND

Medical students hold significant importance, as they represent the future of healthcare provision. This study aimed to explore psychological antecedents towards the monkeypox (mpox) vaccines among postgraduate and undergraduate medical students across countries.

METHODS

A cross-sectional survey was conducted among medical students aged 18 years old and above in 7 countries; Egypt, Romania, Malaysia, and Yemen, Iraq, India, and Nigeria. We used social media platforms between September 27 and November 4, 2022. An anonymous online survey using the 5C scale was conducted using snowball and convenience Sampling methods to assess the 5 psychological antecedents of vaccination (i.e., confidence, constraints, complacency, and calculation, as well as collective responsibility).

RESULTS

A total of 2780 participants were recruited. Participants' median age was 22 years and 52.1% of them were males. The 5C psychological antecedents of vaccination were as follows: 55% were confident about vaccination, 10% were complacent, 12% experienced constraints, and 41% calculated the risk and benefit. Lastly, 32% were willing to be vaccinated for the prevention of infection transmission to others. The Country was a significant predictor of confidence, complacency, having constraints, and calculation domains (P < 0.001). Having any idea about the mpox vaccine was linked to 1.6 times higher odds of being more confident [OR = 1.58 (95% CI, 1.26-1.98), P < 0.001] Additionally, living in a rural area significantly increased complacency [OR = 1.42 (95% CI, 1.05-1.95), P = 0.024] as well as having anyone die from mpox [OR = 3.3 (95% CI, 1.64-6.68), P < 0.001]. Education level was associated with increased calculation [OR = 2.74 (95% CI, 1.62-4.64), P < 0.001]. Moreover, being single and having no chronic diseases significantly increased the calculation domain [OR = 1.40 (95% CI, 1.06-1.98), P = 0.02] and [OR = 1.54 (95% CI, 1.10-2.16), P = 0.012] respectively. Predictors of collective responsibility were age 31-45 years [OR = 2.89 (95% CI, 1.29-6.48), P = 0.01], being single [OR = 2.76 (95% CI, 1.94 -3.92), P < 0.001], being a graduate [OR = 1.59 (95% CI (1.32-1.92), P < 0.001], having no chronic disease [OR = 2.14 (95% CI, 1.56-2.93), P < 0.001], and not knowing anyone who died from mpox [OR = 2.54 (95% CI, 1.39-4.64), P < 0.001), as well as living in a middle-income country [OR = 0.623, (95% CI, 0.51-0.73), P < 0.001].

CONCLUSIONS

This study underscores the multifaceted nature of psychological antecedents of vaccination, emphasizing the impact of socio-demographic factors, geographic location, and awareness, as well as previous experiences on individual attitudes and collective responsibility towards vaccination.

Dry and liquid formulations of IBT-V02, a novel multi-component toxoid vaccine, are effective against Staphylococcus aureus isolates from low-to-middle income countries

Staphylococcus aureus is the leading cause of skin and soft tissue infections (SSTIs) in the U.S. as well as more serious invasive diseases, including bacteremia, sepsis, endocarditis, surgical site infections, osteomyelitis, and pneumonia. These infections are exacerbated by the emergence of antibiotic-resistant clinical isolates such as methicillin-resistant S. aureus (MRSA), highlighting the need for alternatives to antibiotics to treat bacterial infections. We have previously developed a multi-component toxoid vaccine (IBT-V02) in a liquid formulation with efficacy against multiple strains of Staphylococcus aureus prevalent in the industrialized world. However, liquid vaccine formulations are not compatible with the paucity of cold chain storage infrastructure in many low-to-middle income countries (LMICs). Furthermore, whether our IBT-V02 vaccine formulations are protective against S. aureus isolates from LMICs is unknown. To overcome these limitations, we developed lyophilized and spray freeze-dried formulations of IBT-V02 vaccine and demonstrated that both formulations had comparable biophysical attributes as the liquid formulation, including similar levels of toxin neutralizing antibodies and protective efficacy against MRSA infections in murine and rabbit models. To enhance the relevancy of our findings, we then performed a multi-dimensional screen of 83 S. aureus clinical isolates from LMICs (e.g., Democratic Republic of Congo, Palestine, and Cambodia) to rationally down-select strains to test in our in vivo models based on broad expression of IBT-V02 targets (i.e., pore-forming toxins and superantigens). IBT-V02 polyclonal antisera effectively neutralized toxins produced by the S. aureus clinical isolates from LMICs. Notably, the lyophilized IBT-V02 formulation exhibited significant in vivo efficacy in various preclinical infection models against the S. aureus clinical isolates from LMICs, which was comparable to our liquid formulation. Collectively, our findings suggested that lyophilization is an effective alternative to liquid vaccine formulations of our IBT-V02 vaccine against S. aureus infections, which has important implications for protection from S. aureus isolates from LMICs.

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.

Comparison of the immunogenicity and protective efficacy of ACAM2000, MVA, and vectored subunit vaccines for Mpox in rhesus macaques

The 2022-2023 mpox outbreak triggered vaccination efforts using smallpox vaccines that were approved for mpox, including modified vaccinia Ankara (MVA; JYNNEOS), which is a safer alternative to live replicating vaccinia virus (ACAM2000). Here, we compare the immunogenicity and protective efficacy of JYNNEOS by the subcutaneous or intradermal routes, ACAM2000 by the percutaneous route, and subunit Ad35 vector-based L1R/B5R or L1R/B5R/A27L/A33R vaccines by the intramuscular route in rhesus macaques. All vaccines provided robust protection against high-dose intravenous mpox virus challenge with the current outbreak strain, with ACAM2000 providing near complete protection and JYNNEOS and Ad35 vaccines providing robust but incomplete protection. Protection correlated with neutralizing antibody responses as well as L1R/M1R- and B5R/B6R-specific binding antibody responses, although additional immune responses likely also contributed to protection. This study demonstrates the protective efficacy of multiple vaccine platforms against mpox virus challenge, including both current clinical vaccines and vectored subunit vaccines.

How the Orthodox Features of Orthopoxviruses Led to an Unorthodox Mpox Outbreak: What We've Learned, and What We Still Need to Understand

Orthopoxviruses have repeatedly confounded expectations in terms of the clinical illness they cause and their patterns of spread. Monkeypox virus (MPXV), originally characterized in the late 1950s during outbreaks among captive primates, has been recognized since the 1970s to cause human disease (mpox) in West and Central Africa, where interhuman transmission has largely been associated with nonsexual, close physical contact. In May 2022, a focus of MPXV transmission was detected, spreading among international networks of gay, bisexual, and other men who have sex with men. The outbreak grew in both size and geographic scope, testing the strength of preparedness tools and public health science alike. In this article we consider what was known about mpox before the 2022 outbreak, what we learned about mpox during the outbreak, and what continued research is needed to ensure that the global public health community can detect, and halt further spread of this disease threat.

Underdetected dispersal and extensive local transmission drove the 2022 mpox epidemic

The World Health Organization declared mpox a public health emergency of international concern in July 2022. To investigate global mpox transmission and population-level changes associated with controlling spread, we built phylogeographic and phylodynamic models to analyze MPXV genomes from five global regions together with air traffic and epidemiological data. Our models reveal community transmission prior to detection, changes in case reporting throughout the epidemic, and a large degree of transmission heterogeneity. We find that viral introductions played a limited role in prolonging spread after initial dissemination, suggesting that travel bans would have had only a minor impact. We find that mpox transmission in North America began declining before more than 10% of high-risk individuals in the USA had vaccine-induced immunity. Our findings highlight the importance of broader routine specimen screening surveillance for emerging infectious diseases and of joint integration of genomic and epidemiological information for early outbreak control.

Adverse Reactions After Intradermal Vaccination With JYNNEOS for Mpox in Korea

In response to the Mpox domestic epidemic, South Korea initiated a nationwide vaccination program in May 2023, administering a 0.1 mL intradermal dose of JYNNEOS (Modified Vaccinia Ankara vaccine, Bavarian Nordic) to a high-risk group. To investigate the adverse reactions after intradermal JYNNEOS vaccination, an anonymous online survey was conducted at the National Medical Center from May 22 to July 31, 2023. Overall, 142 individuals responded. Over 80% of the respondents reported local reactions of predominantly mild severity. The predominant local reactions were pruritus, redness, and swelling; their incidence rates after the first dose were 66.2%, 48.1%, and 49.4%, respectively; the corresponding rates after the second dose were 69.2%, 60.6%, and 53.8%. Fewer respondents reported systemic symptoms. The most common systemic symptom was fatigue, the incidence rates of which after the first and second doses were 37.7% and 24.6%, respectively. Overall, the intradermally administered JYNNEOS vaccine appeared well tolerated.

Update on Mpox: What the Primary Care Clinician Should Know

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

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.

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.

Current Status of Vaccine Development for Monkeypox Virus

Monkeypox virus (MPXV) of poxviridae family causes a zoonotic disease called monkeypox (Mpox). MPXV cases have a fatality ratio ranging from 0 to 11% globally and have been more prevalent in children. There are three generations of smallpox vaccines that protect against MPXV. First and second generation of the vaccinia virus (VACV) vaccine protects MPXV. However, various adverse side effects were associated with the first and second generations of vaccines. In contrast, the Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN) replication-incompetent vaccine shows fewer adverse effects and a significant amount of neutralizing antibodies in mammalian cells. A third-generation Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN) was approved to prevent Mpox in 2019. Recently, MVA-BN-based Imvanex, Imvamune, and JYNNEOS vaccines have also been administered against MPXV. Globally, the World Health Organization (WHO) declared a global health emergency in May 2022 due to increased MPXV cases. Various computational studies have also designed a multi-epitope-based vaccine against the MPXV. In the multi-epitope-based vaccine, different epitopes like B-cell, Cytotoxic T Lymphocyte (CTL), CD8+, and CD4+ epitopes were derived from MPXV proteins. Further, these epitopes were linked with the help of various linkers to design a multi-epitope vaccine against MPXV. In summary, we have provided an overview of the current status of the vaccine against MPXV.

Early underdetected dissemination across countries followed by extensive local transmission propelled the 2022 mpox epidemic

The World Health Organization declared mpox a public health emergency of international concern in July 2022. To investigate global mpox transmission and population-level changes associated with controlling spread, we built phylogeographic and phylodynamic models to analyze MPXV genomes from five global regions together with air traffic and epidemiological data. Our models reveal community transmission prior to detection, changes in case-reporting throughout the epidemic, and a large degree of transmission heterogeneity. We find that viral introductions played a limited role in prolonging spread after initial dissemination, suggesting that travel bans would have had only a minor impact. We find that mpox transmission in North America began declining before more than 10% of high-risk individuals in the USA had vaccine-induced immunity. Our findings highlight the importance of broader routine specimen screening surveillance for emerging infectious diseases and of joint integration of genomic and epidemiological information for early outbreak control.

Antigen-loaded flagellate bacteria for enhanced adaptive immune response by intradermal injection

Since the skin limits the distribution of intradermal vaccines, a large number of dendritic cells in the skin cannot be fully utilized to elicit a more effective immune response. Here, we loaded the antigen to the surface of the flagellate bacteria that was modified by cationic polymer, thus creating antigen-loaded flagellate bacteria (denoted as 'FB-Ag') to overcome the skin barrier and perform the active delivery of antigen in the skin. The FB-Ag showed fast speed (∼0.2 μm s-1) and strong dendritic cell activation capabilities in the skin model in vitro. In vivo, the FB-Ag promoted the spread of antigen in the skin through active movement, increased the contact between Intradermal dendritic cells and antigen, and effectively activated the internal dendritic cells in the skin. In a mouse of pulmonary metastatic melanoma and in mice bearing subcutaneous melanoma tumor, the FB-Ag effectively increased antigen-specific therapeutic efficacy and produced long-lasting immune memory. More importantly, the FB-Ag also enhanced the level of COVID-19 specific antibodies in the serum and the number of memory B cells in the spleen of mice. The movement of antigen-loaded flagellate bacteria to overcome intradermal constraints may enhance the activation of intradermal dendritic cells, providing new ideas for developing intradermal vaccines.

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.

Effectiveness of the Modified Vaccinia Ankara Vaccine Against Mpox in Men Who Have Sex With Men: A Retrospective Cohort Analysis, Seattle, Washington

Background

Data on modified Vaccinia Ankara (MVA) vaccine effectiveness against mpox in real-world settings are limited.

Methods

We performed a retrospective cohort analysis using Cox proportional hazards regression to estimate the association between vaccination and laboratory-confirmed mpox incidence. Study subjects included all men who have sex with men seen in a sexual health clinic in Seattle, Washington, between 1 January 2020 and 31 December 2022. Subjects' receipt of vaccine and diagnosis with mpox were ascertained from public health vaccine registry and surveillance data. Analyses were adjusted for demographic factors, human immunodeficiency virus (HIV) status, and sexual risk behaviors.

Results

The incidence of mpox per 100 person-years was 8.83 among patients with 0 doses, 3.32 among patients with 1 dose, and 0.78 among patients with 2 doses of MVA vaccine. Mpox diagnosis was significantly associated with age category 30-39 and 40-51 years, HIV positivity, syphilis diagnosis in the prior year, >10 sex partners in the last year, and having a clinic visit in the last year. In the multivariate model adjusting for these factors, vaccine effectiveness was 81% for 1 dose and 83% for 2 doses.

Conclusions

These data support the effectiveness of the MVA vaccine-including a single dose of the vaccine-in preventing mpox disease and highlight the appropriateness of risk factor-based prioritization of immunization early in the epidemic. The durability of MVA vaccine-induced immunity is unknown, and at-risk persons should receive 2 doses of MVA.

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.

Lessons Learned from the U.S. Public Health Response to the 2022 mpox Outbreak

In mid-2022, an mpox outbreak occurred in the United States and more than 100 countries, disproportionately affecting men who have sex with men (MSM). Initially, the U.S. public health system failed to deploy tests, treatment, and vaccines effectively. Key federal policy changes in August 2022, along with risk reduction among many MSM, led to a steady reduction in new diagnoses by December 2022. Mpox outbreaks occurred among MSM in Chicago and France in May 2023, and vaccination rates remain low. This perspective analyzes the U.S. response to the 2022 outbreak, and it identifies the lessons learned that may guide mpox management moving forward.

Assessing the generation of tissue resident memory T cells by vaccines

Vaccines have been a hugely successful public health intervention, virtually eliminating many once common diseases of childhood. However, they have had less success in controlling endemic pathogens including Mycobacterium tuberculosis, herpesviruses and HIV. A focus on vaccine-mediated generation of neutralizing antibodies, which has been a successful approach for some pathogens, has been complicated by the emergence of escape variants, which has been seen for pathogens such as influenza viruses and SARS-CoV-2, as well as for HIV-1. We discuss how vaccination strategies aimed at generating a broad and robust T cell response may offer superior protection against pathogens, particularly those that have been observed to mutate rapidly. In particular, we consider here how a focus on generating resident memory T cells may be uniquely effective for providing immunity to pathogens that typically infect (or become reactivated in) the skin, respiratory mucosa or other barrier tissues.

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.

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.

The prospective outcome of the monkeypox outbreak in 2022 and characterization of monkeypox disease immunobiology

A new threat to global health re-emerged with monkeypox's advent in early 2022. As of November 10, 2022, nearly 80,000 confirmed cases had been reported worldwide, with most of them coming from places where the disease is not common. There were 53 fatalities, with 40 occurring in areas that had never before recorded monkeypox and the remaining 13 appearing in the regions that had previously reported the disease. Preliminary genetic data suggest that the 2022 monkeypox virus is part of the West African clade; the virus can be transmitted from person to person through direct interaction with lesions during sexual activity. It is still unknown if monkeypox can be transmitted via sexual contact or, more particularly, through infected body fluids. This most recent epidemic's reservoir host, or principal carrier, is still a mystery. Rodents found in Africa can be the possible intermediate host. Instead, the CDC has confirmed that there are currently no particular treatments for monkeypox virus infection in 2022; however, antivirals already in the market that are successful against smallpox may mitigate the spread of monkeypox. To protect against the disease, the JYNNEOS (Imvamune or Imvanex) smallpox vaccine can be given. The spread of monkeypox can be slowed through measures such as post-exposure immunization, contact tracing, and improved case diagnosis and isolation. Final Thoughts: The latest monkeypox epidemic is a new hazard during the COVID-19 epidemic. The prevailing condition of the monkeypox epidemic along with coinfection with COVID-19 could pose a serious condition for clinicians that could lead to the global epidemic community in the form of coinfection.

Emerging pharmacological strategies for treating and preventing mpox

INTRODUCTION

Since May 2022, there have been nearly 87,000 documented cases of mpox worldwide, with 119 deaths. Pharmacological interventions for mpox include the MVA-BN smallpox vaccine, tecovirimat, cidofovir, its pro-drug brincidofovir, and vaccinia immune globulin intravenous (VIGIV).

AREAS COVERED

The literature search and information gathering for this review included the PubMed database focusing on mpox and monkeypox, in combination with tecovirimat, brincidofovir, cidofovir, VIGIV, and smallpox vaccine. WHO.int, CDC.gov, FDA.gov, and ClinicalTrials.gov websites were accessed for the most recent information on the mpox outbreak. Mechanisms for deployment and access to treatment including expanded access, emergency use, and clinical trials will be discussed. Treatment outcomes with safety data will be presented.

EXPERT OPINION

The vaccine as a preventive measure, along with numerous treatment options, largely controlled the outbreak, although deployment of each could be improved upon to hasten and broaden access. More widespread coverage by the vaccine is necessary to prevent future resurgence of mpox. Tecovirimat has emerged as a safe frontline treatment for mpox, while brincidofovir use has been limited by safety concerns. VIGIV and cidofovir should be reserved for the most severe cases in which other options are not fully effective.

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.).

Critical Elements of an Mpox Vaccination Model at the Largest Public Health Hospital System in the United States

In the spring of 2022, mpox spread to non-endemic countries, including the United States. In New York City (NYC), vaccine demand grew as quickly as case counts. With the leadership of the Regional Emerging Special Pathogens Treatment Center (RESPTC) at NYC Health and Hospitals/Bellevue (NYC H+H)-part of the largest public hospital system in the United States-an innovative vaccination model was established that overcame challenges involving health inequities, inadequate access, and lack of vaccine uptake, to successfully administer JYNNEOS vaccines to over 12,000 patients. Transmission has slowed since its peak in August 2022, which has been attributed to successful vaccination campaigns, infection-induced immunity, and behavioral changes among those at highest risk; however, a Centers for Disease Control and Prevention (CDC) assessment released on 4 April 2023 suggests jurisdictions with low vaccination levels (<35%) remain at risk for an mpox resurgence. Here, we summarize the critical aspects of our mpox vaccination model in NYC, which include integration into routine clinical care, prioritization of health equity, and reutilization of COVID-19 vaccination systems, to provide valuable insights for healthcare institutions as we move into the next stage of this ongoing outbreak.

Short-term Adverse Events Following Immunization With Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN) Vaccine for Mpox

This study uses data collected by Australia’s vaccine safety surveillance system to examine the adverse event profile of the modified vaccinia Ankara–Bavarian Nordic vaccine.

Preclinical evaluation of performance, safety and usability of VAX-ID®, a novel intradermal injection device

The recent SARS-Cov2 pandemic and mpox health emergency have led to renewed interest in intradermal vaccination due to its dose sparing potential. Indeed, intradermal vaccination is particularly of interest for use in mass vaccination campaigns, pandemic preparedness programs, and/or for vaccines that are expensive or in short supply. Moreover, the rich immune network in the skin makes it an attractive target not only for prophylactic vaccination, but also for therapeutic vaccination, like immunotherapy and (dendritic) cell-based therapies. The aim of the current paper was to provide an overview of preclinical data generated with VAX-ID®, a novel intradermal drug delivery device, to allow assessing it performance, safety and usability. The device can overcome challenges seen with the Mantoux technique whereby the needle needs to be inserted under a shallow angle. Various parameters of VAX-ID® were evaluated, including dead-space volume, dose accuracy, penetration depth & liquid deposit in piglets, as well as usability by healthcare professionals. The device has shown to have a low dead volume and a high dose accuracy. Importantly, the device performed successful injections at a predefined depth into the dermis with a high safety profile as confirmed by visual and histological evaluation in piglets. Moreover, the device was rated as easy to use by healthcare professionals. The combined preclinical performance and usability findings indicate that VAX-ID® can provide reliable, standardized and accurate drug delivery in the dermal layer of the skin with a high ease of use. The device offers a solution for injection of various prophylactic as well as therapeutic vaccines.

T helper 1 effector memory CD4+ T cells protect the skin from poxvirus infection

Poxvirus infections of the skin are a recent emerging public health concern, yet the mechanisms that mediate protective immunity against these viral infections remain largely unknown. Here, we show that T helper 1 (Th1) memory CD4+ T cells are necessary and sufficient to provide complete and broad protection against poxvirus skin infections, whereas memory CD8+ T cells are dispensable. Core 2 O-glycan-synthesizing Th1 effector memory CD4+ T cells rapidly infiltrate the poxvirus-infected skin microenvironment and produce interferon γ (IFNγ) in an antigen-dependent manner, causing global changes in gene expression to promote anti-viral immunity. Keratinocytes express IFN-stimulated genes, upregulate both major histocompatibility complex (MHC) class I and MHC class II antigen presentation in an IFNγ-dependent manner, and require IFNγ receptor (IFNγR) signaling and MHC class II expression for memory CD4+ T cells to protect the skin from poxvirus infection. Thus, Th1 effector memory CD4+ T cells exhibit potent anti-viral activity within the skin, and keratinocytes are the key targets of IFNγ necessary for preventing poxvirus infection of the epidermis.

Effectiveness of JYNNEOS Vaccine Against Diagnosed Mpox Infection - New York, 2022

In 2022, an international Monkeypox virus outbreak, characterized by transmission primarily through sexual contact among gay, bisexual, and other men who have sex with men (MSM), resulted in 375 monkeypox (mpox) cases in the state of New York outside of New York City (NYC).*^,† The JYNNEOS vaccine (Modified Vaccinia Ankara vaccine, Bavarian Nordic), licensed by the U.S. Food and Drug Administration (FDA) against mpox as a 2-dose series, with doses administered 4 weeks apart,^§ was deployed in a national vaccination campaign.^¶ Before this outbreak, evidence to support vaccine effectiveness (VE) against mpox was based on human immunologic and animal challenge studies (1-3). New York State Department of Health (NYSDOH) conducted a case-control study to estimate JYNNEOS VE against diagnosed mpox in New York residents outside of NYC, using data from systematic surveillance reporting. A case-patient was defined as a man aged ≥18 years who received a diagnosis of mpox during July 24-October 31, 2022. Contemporaneous control patients were men aged ≥18 years with diagnosed rectal gonorrhea or primary syphilis and a history of male-to-male sexual contact, without mpox. Case-patients and control patients were matched to records in state immunization systems. JYNNEOS VE was estimated as 1 - odds ratio (OR) x 100, and JYNNEOS vaccination status (vaccinated versus unvaccinated) at the time of diagnosis was compared, using conditional logistic regression models that adjusted for week of diagnosis, region, patient age, and patient race and ethnicity. Among 252 eligible mpox case-patients and 255 control patients, the adjusted VE of 1 dose (received ≥14 days earlier) or 2 doses combined was 75.7% (95% CI = 48.5%-88.5%); the VE for 1 dose was 68.1% (95% CI = 24.9%-86.5%) and for 2 doses was 88.5% (95% CI = 44.1%-97.6%). These findings support recommended 2-dose JYNNEOS vaccination consistent with CDC and NYSDOH guidance.

Evaluation of mpox vaccine dose-sparing strategies

The spring-summer 2022 mpox outbreak had over 50,000 cases globally, most of them in gay, bisexual, and other men who have sex with men (MSM). In response to vaccine shortages, several countries implemented dose-sparing vaccination strategies, stretching a full-dose vaccine vial into up to five fractional-dose vaccines. Recent studies have found mixed results regarding the effectiveness of the mpox vaccine, raising the question of the utility of dose-sparing strategies. We used an age- and risk-stratified mathematical model of an urban MSM population in the United States with ∼12% high-risk MSM to evaluate potential benefits from implementing dose-sparing vaccination strategies in which a full dose is divided into 3.5 fractional doses. We found that results strongly depend on the fractional-dose vaccine effectiveness (VE) and vaccine supply. With very limited vaccines available, enough to protect with a full dose approximately one-third of the high-risk population, dose-sparing strategies are more beneficial provided that fractional doses preserved at least 40% of full-dose effectiveness (34% absolute VE), projecting 13% (34% VE) to 70% (68% absolute VE) fewer infections than full-dose strategies. In contrast, if vaccine supply is enough to cover the majority of the high-risk population, dose-sparing strategies can be outperformed by full-dose strategies. Scenarios in which fractional dosing was 34% efficacious resulted in almost three times more infections than full dosing. Our analysis suggests that when mpox vaccine supply is limited and fractional-dose vaccination retains moderate effectiveness, there are meaningful health benefits from providing a smaller dose to a larger number of people in the high-risk population. These findings should inform the public-health response to future mpox outbreaks.

Mpox in the United States: Current implications for public health nursing

In 2022, mpox, an orthopoxvirus first isolated in 1958 in cynomolgus monkeys, became a global public health threat. While the virus can be communicated through skin-to-skin contact from any infected person to non-infected person, most cases in the United States have been in gay and bisexual men. Consequently, early public health and community-based efforts concentrated on reducing infections in this population. This article explores current mpox case count epidemiologic data and trends. In addition, vaccination indications, contraindications, adverse events, and national administration data are provided along with directions for nurses and other clinicians moving forward in the outbreak.

A compilation answering 50 questions on monkeypox virus and the current monkeypox outbreak

The current monkeypox disease (MPX) outbreak constitutes a new threat and challenge for our society. With more than 55,000 confirmed cases in 103 countries, World Health Organization declared the ongoing MPX outbreak a Public Health Emergency of International Concern (PHEIC) on July 23, 2022. The current MPX outbreak is the largest, most widespread, and most serious since the diagnosis of the first case of MPX in 1970 in the Democratic Republic of the Congo (DRC), a country where MPX is an endemic disease. Throughout history, there have only been sporadic and self-limiting outbreaks of MPX outside Africa, with a total of 58 cases described from 2003 to 2021. This figure contrasts with the current outbreak of 2022, in which more than 55,000 cases have been confirmed in just 4 months. MPX is, in most cases, self-limiting; however, severe clinical manifestations and complications have been reported. Complications are usually related to the extent of virus exposure and patient health status, generally affecting children, pregnant women, and immunocompromised patients. The expansive nature of the current outbreak leaves many questions that the scientific community should investigate and answer in order to understand this phenomenon better and prevent new threats in the future. In this review, 50 questions regarding monkeypox virus (MPXV) and the current MPX outbreak were answered in order to provide the most updated scientific information and to explore the potential causes and consequences of this new health threat.

Monkeypox virus: A review

While monkeypox was previously found in Africa, the bulk of occurrences in the present outbreak are being reported in many countries. It is not yet known how this outbreak began, and as the COVID-19 crisis begins to abate, numerous nations throughout the world are now contending with a novel outbreak. Monkeypox is a transmissible virus between animals and humans, belonging to the Orthopoxvirus genus of the Poxviridae family. In the 1970s, cases of monkeypox began increasing due to the cessation of vaccination against smallpox, which drew international attention. The virus was named monkeypox because it was first observed in macaque monkeys. It is thought to be transmitted by several different rodents and small mammals, though the origin of the virus is not known. Monkeypox, while occasionally transmitted from one human to another, can be disseminated through the inhalation of droplets or through contact with the skin lesions of an infected individual. Unfortunately, there is no definitive cure for monkeypox; however, supportive care can be offered to ameliorate its symptoms. In severe cases, medications like tecovirimat may be administered. However, there are no established guidelines for symptom management in monkeypox cases. In this article we have discussed about different aspects of monkeypox including viral structure, transmission, replication, clinical manifestations, vaccination, treatment and current prevalence in the world to understand it better and give insight to the future studies.