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Viruses May 2024Vaccinia virus is the most successful vaccine in human history and functions as a protective vaccine against smallpox and monkeypox, highlighting the importance of... (Review)
Review
Vaccinia virus is the most successful vaccine in human history and functions as a protective vaccine against smallpox and monkeypox, highlighting the importance of ongoing research into vaccinia due to its genetic similarity to other emergent poxviruses. Moreover, vaccinia's ability to accommodate large genetic insertions makes it promising for vaccine development and potential therapeutic applications, such as oncolytic agents. Thus, understanding how superior immunity is generated by vaccinia is crucial for designing other effective and safe vaccine strategies. During vaccinia inoculation by scarification, the skin serves as a primary site for the virus-host interaction, with various cell types playing distinct roles. During this process, hematopoietic cells undergo abortive infections, while non-hematopoietic cells support the full viral life cycle. This differential permissiveness to viral replication influences subsequent innate and adaptive immune responses. Dendritic cells (DCs), key immune sentinels in peripheral tissues such as skin, are pivotal in generating T cell memory during vaccinia immunization. DCs residing in the skin capture viral antigens and migrate to the draining lymph nodes (dLN), where they undergo maturation and present processed antigens to T cells. Notably, CD8+ T cells are particularly significant in viral clearance and the establishment of long-term protective immunity. Here, we will discuss vaccinia virus, its continued relevance to public health, and viral strategies permissive to immune escape. We will also discuss key events and populations leading to long-term protective immunity and remaining key gaps.
Topics: Vaccinia virus; Humans; Immune Evasion; Animals; Vaccinia; Dendritic Cells; Virus Replication; Adaptive Immunity; CD8-Positive T-Lymphocytes
PubMed: 38932162
DOI: 10.3390/v16060870 -
Emerging Microbes & Infections Jun 2024The (OPXV) genus of the includes human pathogens variola virus (VARV), monkeypox virus (MPXV), vaccinia virus (VACV), and a number of zoonotic viruses. A number of...
The (OPXV) genus of the includes human pathogens variola virus (VARV), monkeypox virus (MPXV), vaccinia virus (VACV), and a number of zoonotic viruses. A number of Bcl-2-like proteins of VACV are involved in escaping the host innate immunity. However, little work has been devoted to the evolution and function of their orthologues in other OPXVs. Here, we found that MPXV protein P2, encoded by the gene, and P2 orthologues from other OPXVs, such as VACV protein N2, localize to the nucleus and antagonize interferon (IFN) production. Exceptions to this were the truncated P2 orthologues in camelpox virus (CMLV) and taterapox virus (TATV) that lacked the nuclear localization signal (NLS). Mechanistically, the NLS of MPXV P2 interacted with karyopherin α-2 (KPNA2) to facilitate P2 nuclear translocation, and competitively inhibited KPNA2-mediated IRF3 nuclear translocation and downstream IFN production. Deletion of the NLS in P2 or orthologues significantly enhanced IRF3 nuclear translocation and innate immune responses, thereby reducing viral replication. Moreover, deletion of NLS from N2 in VACV attenuated viral replication and virulence in mice. These data demonstrate that the NLS-mediated translocation of P2 is critical for P2-induced inhibition of innate immunity. Our findings contribute to an in-depth understanding of the mechanisms of OPXV P2 orthologue in innate immune evasion.
PubMed: 38916407
DOI: 10.1080/22221751.2024.2372344 -
Journal of Virology Jun 2024The reoccurrence of successive waves of SARS-CoV-2 variants suggests the exploration of more vaccine alternatives is imperative. Modified vaccinia virus Ankara (MVA) is...
UNLABELLED
The reoccurrence of successive waves of SARS-CoV-2 variants suggests the exploration of more vaccine alternatives is imperative. Modified vaccinia virus Ankara (MVA) is a virus vector exhibiting excellent safety as well as efficacy for vaccine development. Here, a series of recombinant MVAs (rMVAs) expressing monomerized or trimerized S proteins from different SARS-CoV-2 variants are engineered. Trimerized S expressed from rMVAs is found predominantly as trimers on the surface of infected cells. Remarkably, immunization of mice with rMVAs demonstrates that S expressed in trimer elicits higher levels of binding IgG and IgA, as well as neutralizing antibodies for matched and mismatched S proteins than S in the monomer. In addition, trimerized S expressed by rMVA induces enhanced cytotoxic T-cell responses than S in the monomer. Importantly, the rMVA vaccines expressing trimerized S exhibit superior protection against a lethal SARS-CoV-2 challenge as the immunized animals all survive without displaying any pathological conditions. This study suggests that opting for trimerized S may represent a more effective approach and highlights that the MVA platform serves as an ideal foundation to continuously advance SARS-CoV-2 vaccine development.
IMPORTANCE
MVA is a promising vaccine vector and has been approved as a vaccine for smallpox and mpox. Our analyses suggested that recombinant MVA expressing S in trimer (rMVA-ST) elicited robust cellular and humoral immunity and was more effective than MVA-S-monomer. Importantly, the rMVA-ST vaccine was able to stimulate decent cross-reactive neutralization against pseudoviruses packaged using S from different sublineages, including Wuhan, Delta, and Omicron. Remarkably, mice immunized with rMVA-ST were completely protected from a lethal challenge of SARS-CoV-2 without displaying any pathological conditions. Our results demonstrated that an MVA vectored vaccine expressing trimerized S is a promising vaccine candidate for SARS-CoV-2 and the strategy might be adapted for future vaccine development for coronaviruses.
PubMed: 38874361
DOI: 10.1128/jvi.00521-24 -
American Journal of Kidney Diseases :... Jun 2024Monkeypox (mpox) is an orthopoxviral zoonotic disease with a similar, but less severe, clinical presentation as smallpox. However, immunocompromised patients such as...
Monkeypox (mpox) is an orthopoxviral zoonotic disease with a similar, but less severe, clinical presentation as smallpox. However, immunocompromised patients such as solid organ transplant recipients are at higher risk of developing severe forms of the disease. Herein, we describe the case of a 43 years-old female kidney transplant recipient that manifested severe skin ulcers alongside nodular lung opacities and pleural effusion attributed directly to the Monkeypox virus. Notwithstanding the initiation of early treatment with tecovirimat, a satisfactory response was not achieved until a reduction in immunosuppression to everolimus monotherapy, coupled with the transition to cidofovir for antiviral treatment. In conclusion, mpox has the potential to produce a severe form of systemic infection in individuals who have undergone solid organ transplantation, demanding a meticulous approach involving sequential antiviral treatment and modifications to immunosuppressive regimens in order to achieve complete healing.
PubMed: 38866126
DOI: 10.1053/j.ajkd.2024.06.001 -
Journal of Infection and Public Health Jul 2024Poxviruses comprise a group of large double-stranded DNA viruses and are known to cause diseases in humans, livestock animals, and other animal species. The Mpox virus...
Formulation of next-generation polyvalent vaccine candidates against three important poxviruses by targeting DNA-dependent RNA polymerase using an integrated immunoinformatics and molecular modeling approach.
BACKGROUND
Poxviruses comprise a group of large double-stranded DNA viruses and are known to cause diseases in humans, livestock animals, and other animal species. The Mpox virus (MPXV; formerly Monkeypox), variola virus (VARV), and volepox virus (VPXV) are among the prevalent poxviruses of the Orthopoxviridae genera. The ongoing Mpox infectious disease pandemic caused by the Mpox virus has had a major impact on public health across the globe. To date, only limited repurposed antivirals and vaccines are available for the effective treatment of Mpox and other poxviruses that cause contagious diseases.
METHODS
The present study was conducted with the primary goal of formulating multi-epitope vaccines against three evolutionary closed poxviruses i.e., MPXV, VARV, and VPXV using an integrated immunoinformatics and molecular modeling approach. DNA-dependent RNA polymerase (DdRp), a potential vaccine target of poxviruses, has been used to determine immunodominant B and T-cell epitopes followed by interactions analysis with Toll-like receptor 2 at the atomic level.
RESULTS
Three multi-epitope vaccine constructs, namely DdRp_MPXV (V1), DdRp_VARV (V2), and DdRp_VPXV (V3) were designed. These vaccine constructs were found to be antigenic, non-allergenic, non-toxic, and soluble with desired physicochemical properties. Protein-protein docking and interaction profiling analysis depicts a strong binding pattern between the targeted immune receptor TLR2 and the structural models of the designed vaccine constructs, and manifested a number of biochemical bonds (hydrogen bonds, salt bridges, and non-bonded contacts). State-of-the-art all-atoms molecular dynamics simulations revealed highly stable interactions of vaccine constructs with TLR2 at the atomic level throughout the simulations on 300 nanoseconds. Additionally, the outcome of the immune simulation analysis suggested that designed vaccines have the potential to induce protective immunity against targeted poxviruses.
CONCLUSIONS
Taken together, formulated next-generation polyvalent vaccines were found to have good efficacy against closely related poxviruses (MPXV, VARV, and VPXV) as demonstrated by our extensive immunoinformatics and molecular modeling evaluations; however, further experimental investigations are still needed.
Topics: Viral Vaccines; Poxviridae; Computational Biology; Epitopes, T-Lymphocyte; DNA-Directed RNA Polymerases; Models, Molecular; Animals; Humans; Poxviridae Infections; Epitopes, B-Lymphocyte; Molecular Docking Simulation; Immunoinformatics
PubMed: 38865776
DOI: 10.1016/j.jiph.2024.102470 -
The Journal of General Virology Jun 2024Increased human-to-human transmission of monkeypox virus (MPXV) is cause for concern, and antibodies directed against vaccinia virus (VACV) are known to confer...
Increased human-to-human transmission of monkeypox virus (MPXV) is cause for concern, and antibodies directed against vaccinia virus (VACV) are known to confer cross-protection against Mpox. We used 430 serum samples derived from the Scottish patient population to investigate antibody-mediated cross-neutralization against MPXV. By combining electrochemiluminescence immunoassays with live-virus neutralization assays, we show that people born when smallpox vaccination was routinely offered in the United Kingdom have increased levels of antibodies that cross-neutralize MPXV. Our results suggest that age is a risk factor of Mpox infection, and people born after 1971 are at higher risk of infection upon exposure.
Topics: Humans; Antibodies, Viral; Smallpox Vaccine; Adult; Middle Aged; Monkeypox virus; Young Adult; Antibodies, Neutralizing; Mpox (monkeypox); Female; Adolescent; Aged; Male; Cross Protection; Scotland; Age Factors; Neutralization Tests; Child; Vaccination; Smallpox; Child, Preschool; Cross Reactions; Aged, 80 and over
PubMed: 38861287
DOI: 10.1099/jgv.0.001999 -
Journal of Medical Virology Jun 2024Since May 2022, several countries outside of Africa experienced multiple clusters of monkeypox virus (MPXV)-associated disease. In the present study, anti-MPXV and...
Since May 2022, several countries outside of Africa experienced multiple clusters of monkeypox virus (MPXV)-associated disease. In the present study, anti-MPXV and anti-vaccinia virus (VACV) neutralizing antibody responses were evaluated in two cohorts of subjects from the general Italian population (one half born before the WHO-recommended end of smallpox vaccination in 1980, the other half born after). Higher titers (either against MPXV or VACV) were observed in the cohort of individuals born before the interruption of VACV vaccination. An association between VACV and MPXV antibody levels was observed, suggesting that the smallpox vaccination may confer some degree of cross-protection against MPXV infection. Results from this study highlight low levels of immunity toward the assessed Orthopoxviruses, especially in young adults, advocating the introduction of a VACV- or MPXV-specific vaccine in case of resurgence of monkeypox disease outbreaks.
Topics: Humans; Antibodies, Neutralizing; Antibodies, Viral; Male; Adult; Female; Smallpox Vaccine; Italy; Monkeypox virus; Young Adult; Seroepidemiologic Studies; Middle Aged; Vaccination; Vaccinia virus; Mpox (monkeypox); Adolescent; Smallpox; Cross Protection; Aged; Cohort Studies; Child
PubMed: 38860589
DOI: 10.1002/jmv.29728 -
Current Opinion in Ophthalmology Jun 2024To highlight the clinical features of mpox with an emphasis on ocular manifestations and to review treatment options for this re-emerging infectious disease.
PURPOSE OF REVIEW
To highlight the clinical features of mpox with an emphasis on ocular manifestations and to review treatment options for this re-emerging infectious disease.
RECENT FINDINGS
Ocular involvement of mpox varies by clade. The most recent 2022 outbreak appears to be associated with fewer conjunctivitis cases compared to previous outbreaks. However, the ocular findings occurring during this newly emerging clade can be visually threatening and include cases of keratitis, rapidly progressing scleritis, and necrotizing periorbital rashes.
SUMMARY
Ocular mpox is an important clinical feature of systemic mpox virus (MPXV) infection. Heightened clinical suspicion allows for a timely diagnosis and the initiation of antiviral treatment, when appropriate. Randomized clinical trials for mpox systemic and ocular treatment efficacy are lacking. Prior clinical experience with smallpox and in-vitro mpox data support the use of systemic antivirals such as tecovirimat, cidofovir, brincidofovir and topical use of trifluridine in ocular mpox management, though treatment-resistant infection can occur and portend a poor prognosis.
PubMed: 38847744
DOI: 10.1097/ICU.0000000000001066 -
Veterinary Medicine International 2024This review delves into the historical context, current epidemiological landscape, genomics, and pathobiology of monkeypox virus (MPXV). Furthermore, it elucidates the... (Review)
Review
This review delves into the historical context, current epidemiological landscape, genomics, and pathobiology of monkeypox virus (MPXV). Furthermore, it elucidates the present vaccination status and strategies to curb the spread of monkeypox. Monkeypox, caused by the known as MPXV, is a zoonotic ailment. MPXV can be transmitted from person to person through respiratory droplets during prolonged face-to-face interactions. While many cases of monkeypox are self-limiting, vulnerable groups such as young children, pregnant women, and immunocompromised individuals may experience severe manifestations. Diagnosis predominantly relies on clinical presentations, complemented by laboratory techniques like RT-PCR. Although treatment is often not required, severe cases necessitate antiviral medications like tecovirimat, cidofovir, and brincidofovir. Vaccination, particularly using the smallpox vaccine, has proven instrumental in outbreak control, exhibiting an efficacy of at least 85% against mpox as evidenced by data from Africa. Mitigating transmission requires measures like wearing surgical masks, adequately covering skin lesions, and avoiding handling wild animals.
PubMed: 38836166
DOI: 10.1155/2024/8839830 -
Infectious Medicine Jun 2024In 2022, just before the COVID-19 pandemic ended, many countries noticed a viral monkeypox outbreak. Monkeypox virus, a zoonotic pathogen, causes a febrile illness in... (Review)
Review
In 2022, just before the COVID-19 pandemic ended, many countries noticed a viral monkeypox outbreak. Monkeypox virus, a zoonotic pathogen, causes a febrile illness in humans and resembles smallpox. Prevention strategies encompass vaccination, strict infection control measures, and avoiding contact with infected persons. As monkeypox and related poxviruses continue to pose challenges, ongoing surveillance, early diagnosis, prompt isolation, and effective control measures are crucial for limiting transmission and mitigating the impact of outbreaks on public health. This review provides valuable insights into the evolution of the monkeypox virus and its various modes of transmission, including postmortem transmission, and offers an overall perspective on the guidelines issued by the Government of India to prevent and effectively control the spread of this disease.
PubMed: 38827561
DOI: 10.1016/j.imj.2024.100105