Mpox mRNA-1769 vaccine inhibits orthopoxvirus replication at intranasal, intrarectal, and cutaneous sites of inoculation.

We previously reported that mice immunized twice with a lipid nanoparticle vaccine comprising four monkeypox viral mRNAs raised neutralizing antibodies and antigen-specific T cells and were protected against a lethal intranasal challenge with vaccinia virus (VACV). Here we demonstrated that the mRNA vaccine also protects mice against intranasal and intraperitoneal infections with monkeypox virus and bioluminescence imaging showed that vaccination greatly reduces or prevents VACV replication and spread from intranasal, rectal, and dermal inoculation sites. A single vaccination provided considerable protection that was enhanced by boosting for at least 4 months.

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

In 2022, mpox virus (MPXV) spread worldwide, causing 99,581 mpox cases in 121 countries. Modified vaccinia Ankara (MVA) vaccine use reduced disease in at-risk populations but failed to deliver complete protection. Lag in manufacturing and distribution of MVA resulted in additional MPXV spread, with 12,000 reported cases in 2023 and an additional outbreak in Central Africa of clade I virus.

Protection from SARS-CoV-2 Variants by MVAs expressing matched or mismatched S administered intranasally to mice.

SARS-CoV-2 vaccines prevent severe disease but are less efficient in averting infection and transmission of variant strains, making it imperative to explore ways of enhancing protection. Use of inbred mice expressing the human SARS-CoV-2 receptor facilitates such investigations. We employed recombinant MVAs (rMVAs) expressing modified S of several SARS-CoV-2 strains and compared their ability to neutralize variants, bind S proteins and protect K18-hACE2 mice against SARS-CoV-2 challenge when administered intramuscularly or intranasally.

Inhibition of vaccinia virus L1 N-myristoylation by the host N-myristoyltransferase inhibitor IMP-1088 generates non-infectious virions defective in cell entry.

We have recently shown that the replication of rhinovirus, poliovirus and foot-and-mouth disease virus requires the co-translational N-myristoylation of viral proteins by human host cell N-myristoyltransferases (NMTs), and is inhibited by treatment with IMP-1088, an ultrapotent small molecule NMT inhibitor. Here, we examine the importance of N-myristoylation during vaccinia virus (VACV) infection in primate cells and demonstrate the anti-poxviral effects of IMP-1088. N-myristoylated proteins from VACV and the host were metabolically labelled with myristic acid alkyne during infection using quantitative chemical proteomics.

Intranasal inoculation of an MVA-based vaccine induces IgA and protects the respiratory tract of hACE2 mice from SARS-CoV-2 infection.

Current vaccines have greatly diminished the severity of the COVID-19 pandemic, even though they do not entirely prevent infection and transmission, likely due to insufficient immunity in the upper respiratory tract. Here, we compare intramuscular and intranasal administration of a live, replication-deficient modified vaccinia virus Ankara (MVA)-based Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) spike (S) vaccine to raise protective immune responses in the K18-hACE2 mouse model. Using a recombinant MVA expressing firefly luciferase for tracking, live imaging revealed luminescence of the respiratory tract of mice within 6 h and persisting for 3 d following intranasal inoculation, whereas luminescence remained at the site of intramuscular vaccination.

Interferon α/β Decoy Receptor Encoded by a Variant in the Dryvax Smallpox Vaccine Contributes to Virulence and Correlates with Severe Vaccine Side Effects.

Although providing long-lasting immunity, smallpox vaccination was associated with local and systemic reactions and rarely with severe complications, including progressive vaccinia and postvaccinia encephalitis. As the Dryvax smallpox vaccine consists of a population of variants, we investigated a particularly pathogenic isolate called clone 3 (CL3). Virus replication was monitored by inserting the gene encoding firefly luciferase (Luc) into the genomes of CL3 and ACAM2000, the second-generation smallpox vaccine derived from a less virulent clone.

One or two injections of MVA-vectored vaccine shields hACE2 transgenic mice from SARS-CoV-2 upper and lower respiratory tract infection.

Modified vaccinia virus Ankara (MVA) is a replication-restricted smallpox vaccine, and numerous clinical studies of recombinant MVAs (rMVAs) as vectors for prevention of other infectious diseases, including COVID-19, are in progress. Here, we characterize rMVAs expressing the S protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Modifications of full-length S individually or in combination included two proline substitutions, mutations of the furin recognition site, and deletion of the endoplasmic retrieval signal.

MVA Vector Vaccines Inhibit SARS CoV-2 Replication in Upper and Lower Respiratory Tracts of Transgenic Mice and Prevent Lethal Disease.

Replication-restricted modified vaccinia virus Ankara (MVA) is a licensed smallpox vaccine and numerous clinical studies investigating recombinant MVAs (rMVAs) as vectors for prevention of other infectious diseases have been completed or are in progress. Two rMVA COVID-19 vaccine trials are at an initial stage, though no animal protection studies have been reported. Here, we characterize rMVAs expressing the S protein of CoV-2.

Characterisation of fasted state gastric and intestinal fluids collected from children.

Fundamental knowledge about the composition of intestinal fluids in paediatric populations is currently unavailable. This study aimed to characterise gastric and intestinal fluid from paediatric populations. Gastric and intestinal fluid samples were obtained during routine clinical endoscopy from paediatric patients at a large teaching hospital.

Mutations Near the N Terminus of Vaccinia Virus G9 Protein Overcome Restrictions on Cell Entry and Syncytium Formation Imposed by the A56/K2 Fusion Regulatory Complex.

The entry/fusion complex (EFC) consists of 11 conserved proteins embedded in the membrane envelope of mature poxvirus particles. Poxviruses also encode proteins that localize in cell membranes and negatively regulate superinfection and syncytium formation. The vaccinia virus (VACV) A56/K2 fusion regulatory complex associates with the G9/A16 EFC subcomplex, but functional support for the importance of this interaction was lacking.

Preparation of Cell Cultures and Vaccinia Virus Stocks.

The culturing of cell lines used with vaccinia virus, both as monolayer and in suspension, is described. The preparation of chick embryo fibroblasts (CEF) is presented for use in the production of the highly attenuated and host range-restricted modified vaccinia virus Ankara (MVA) strain of vaccinia virus. Protocols for the preparation, titration, and trypsinization of vaccinia virus stocks, as well as viral DNA preparation and virus purification methods are also included.

Preparation of Cell Cultures and Vaccinia Virus Stocks.

The culturing of cell lines used with vaccinia virus, both as monolayer and in suspension, is described. The preparation of chick embryo fibroblasts (CEF) is presented for use in the production of the highly attenuated and host range-restricted modified vaccinia virus Ankara (MVA) strain of vaccinia virus. Protocols for the preparation, titration, and trypsinization of vaccinia virus stocks, as well as viral DNA preparation and virus purification methods are also included.

Preparation of Cell Cultures and Vaccinia Virus Stocks.

The culturing of cell lines used with vaccinia virus, both as monolayer and in suspension, is described. The preparation of chick embryo fibroblasts (CEF) is presented for use in the production of the highly attenuated and host range-restricted modified vaccinia virus Ankara (MVA) strain of vaccinia virus. Protocols for the preparation, titration, and trypsinization of vaccinia virus stocks, as well as viral DNA preparation and virus purification methods are also included.

Comparative live bioluminescence imaging of monkeypox virus dissemination in a wild-derived inbred mouse (Mus musculus castaneus) and outbred African dormouse (Graphiurus kelleni).

Monkeypox virus belongs to the orthopoxvirus genus, infects rodents and monkeys in Africa, produces a smallpox-like zoonotic disease in humans, and has the potential for global spread and exploitation for bioterrorism. Several small animal models for studying monkeypox virus pathogenesis have been investigated. The African dormouse is a candidate natural host but is outbred and no immunological reagents exist.

Duplication of the A17L locus of vaccinia virus provides an alternate route to rifampin resistance.

Unlabelled: Specific gene duplications can enable double-stranded DNA viruses to adapt rapidly to environmental pressures despite the low mutation rate of their high-fidelity DNA polymerases. We report on the rapid positive selection of a novel vaccinia virus genomic duplication mutant in the presence of the assembly inhibitor rifampin. Until now, all known rifampin-resistant vaccinia virus isolates have contained missense mutations in the D13L gene, which encodes a capsid-like scaffold protein required for stabilizing membrane curvature during the early stage of virion assembly.

Susceptibility of the wild-derived inbred CAST/Ei mouse to infection by orthopoxviruses analyzed by live bioluminescence imaging.

Classical inbred mice are extensively used for virus research. However, we recently found that some wild-derived inbred mouse strains are more susceptible than classical strains to monkeypox virus. Experiments described here indicated that the 50% lethal dose of vaccinia virus (VACV) and cowpox virus (CPXV) were two logs lower in wild-derived inbred CAST/Ei mice than classical inbred BALB/c mice, whereas there was little difference in the susceptibility of the mouse strains to herpes simplex virus.

Reverse genetics analysis of poxvirus intermediate transcription factors.

Vaccinia virus transcription is regulated in three stages. An intermediate transcription factor, comprised of virus-encoded polypeptides A8 and A23, was previously identified by in vitro analyses. To investigate its role, we engineered cells that stably expressed both subunits and complemented the replication of A8 and A23 deletion mutant viruses.

Duration of etanercept treatment and reasons for discontinuation in a cohort of juvenile idiopathic arthritis patients.

Objective: Since 2004, juvenile idiopathic arthritis (JIA) patients treated with etanercept and/or MTX have been monitored in the British Society for Paediatric and Adolescent Rheumatology Biologics and New Drug Register. Here, we report the duration of etanercept use for the first 5 years of the register and reasons for discontinuation.

Methods: Disease subtype and activity, comorbidity, treatment efficacy and safety data were recorded.

Design and evaluation of multi-gene, multi-clade HIV-1 MVA vaccines.

Recombinant modified vaccinia virus Ankara (rMVA) expressing HIV-1 genes are promising vaccine candidates. Toward the goal of conducting clinical trials with one or a cocktail of recombinant viruses, four rMVAs expressing env and gag-pol genes from primary HIV-1 isolates representing predominant subtypes from Kenya, Tanzania, Uganda, and Thailand (A, C, D, and CRF01_AE, respectively) were constructed. Efficient expression, processing, and function of Env and Gag were demonstrated.

Elucidating and minimizing the loss by recombinant vaccinia virus of human immunodeficiency virus gene expression resulting from spontaneous mutations and positive selection.

While characterizing modified vaccinia virus recombinants (rMVAs) containing human immunodeficiency virus env and gag-pol genes, we detected nonexpressing mutants by immunostaining individual plaques. In many cases, the numbers of mutants increased during successive passages, indicating strong selection pressure. This phenomenon provided an opportunity to investigate the formation of spontaneous mutations in vaccinia virus, which encodes its own cytoplasmic replication system, and a challenge to reduce the occurrence of mutations for vaccine production.