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We assessed the humoral and cellular response to the fourth BNT162b2 mRNA COVID-19 vaccine dose in patients with CLL. A total of 67 patients with CLL and 85 age matched controls tested for serologic response and pseudo-neutralization assay. We also tested the functional T-cell response by interferon gamma (IFNγ) to spike protein in 26 patients. Two weeks after the fourth vaccine antibody serologic response was evident in 37 (55.2%) patients with CLL, 20 /22 (91%) of treatment naïve, and 9/32 (28%) patients with ongoing therapy, compared with 100% serologic response in age matched controls. The antibody titer increased by 10-fold in patients with CLL, however, still 88-folds lower than age matched controls. Predictors of better chances of post fourth vaccination serologic response were previous positive serologies after second, third, and pre-fourth vaccination, neutralizing assay, and treatment naïve patients. T-cell response improved from 42.3% before the fourth vaccine to 84.6% 2 weeks afterwards. During the time period of 3 months after the fourth vaccination, 14 patients (21%) developed COVID-19 infection, all recovered uneventfully. Our data demonstrate that fourth SARS-CoV-2 vaccination improves serologic response in patients with CLL to a lesser extent than healthy controls and induces functional T-cell response.

Since the emergence of the original SARS-CoV-2, several variants were described, raising questions as to the ability of recently developed vaccine platforms to induce immunity and provide protection against these variants. Here, we utilized the K18-hACE2 mouse model to show that VSV-ΔG-spike vaccination provides protection against several SARS-CoV-2 variants: alpha, beta, gamma, and delta. We show an overall robust immune response, regardless of variant identity, leading to reduction in viral load in target organs, prevention of morbidity and mortality, as well as prevention of severe brain immune response, which follows infection with various variants. Additionally, we provide a comprehensive comparison of the brain transcriptomic profile in response to infection with different variants of SARS-CoV-2 and show how vaccination prevents these disease manifestations. Taken together, these results highlight the robust VSV-ΔG-spike protective response against diverse SARS-CoV-2 variants, as well as its promising potential against newly arising variants.

rVSV-ΔG-SARS-CoV-2-S is a clinical stage (Phase 2) replication competent recombinant vaccine against SARS-CoV-2. To evaluate the safety profile of the vaccine, a series of non-clinical safety, immunogenicity and efficacy studies were conducted in four animal species, using multiple doses (up to 108 Plaque Forming Units/animal) and dosing regimens. There were no treatment-related mortalities or any noticeable clinical signs in any of the studies. Compared to unvaccinated controls, hematology and biochemistry parameters were unremarkable and no adverse histopathological findings. There was no detectable viral shedding in urine, nor viral RNA detected in whole blood or serum samples seven days post vaccination. The rVSV-ΔG-SARS-CoV-2-S vaccination gave rise to neutralizing antibodies, cellular immune responses, and increased lymphocytic cellularity in the spleen germinal centers and regional lymph nodes. No evidence for neurovirulence was found in C57BL/6 immune competent mice or in highly sensitive type I interferon knock-out mice. Vaccine virus replication and distribution in K18-human Angiotensin-converting enzyme 2-transgenic mice showed a gradual clearance from the vaccination site with no vaccine virus recovered from the lungs. The nonclinical data suggest that the rVSV-ΔG-SARS-CoV-2-S vaccine is safe and immunogenic. These results supported the initiation of clinical trials, currently in Phase 2. Supplementary Information The online version contains supplementary material available at 10.1007/s00204-021-03214-w.

Virus-induced CNS diseases impose a considerable human health burden worldwide. For many viral CNS infections, neither antiviral drugs nor vaccines are available. In this study, we examined whether the synthesis of glycosphingolipids, major membrane lipid constituents, could be used to establish an antiviral therapeutic target. We found that neuroinvasive Sindbis virus altered the sphingolipid levels early after infection in vitro and increased the levels of gangliosides GA1 and GM1 in the sera of infected mice. The alteration in the sphingolipid levels appears to play a role in neuroinvasive Sindbis virus replication, as treating infected cells with UDP-glucose ceramide glucosyltransferase (UGCG) inhibitors reduced the replication rate. Moreover, the UGCG inhibitor GZ-161 increased the survival rates of Sindbis-infected mice, most likely by reducing the detrimental immune response activated by sphingolipids in the brains of Sindbis virus-infected mice. These findings suggest a role for glycosphingolipids in the host immune response against neuroinvasive Sindbis virus and suggest that UGCG inhibitors should be further examined as antiviral therapeutics for viral infections of the CNS.

The current monkeypox virus global spread and lack of data regarding clinical specimens’ infectivity call for examining virus infectivity, and whether this correlates with results from PCR, the available diagnostic tool. We show strong correlation between viral DNA amount in clinical specimens and virus infectivity toward BSC-1 cell line. Moreover, we define a PCR threshold value (Cq ≥ 35, ≤ 4,300 DNA copies/mL), corresponding to negative viral cultures, which may assist risk-assessment and decision-making regarding protective-measures and guidelines for patients with monkeypox.

In light of the alarming global spread of Monkeypox and the lack of data regarding virus infectivity in clinical specimens, we examined virus infectivity and its correlation with PCR results, the currently available diagnostic tool. Due to the high risk of Monkeypox virus infection, only a limited number of approved BSL-3 laboratories employed with vaccinated staff, including ourselves, are capable of determining Monkeypox virus infectivity. We show strong correlation between viral DNA content and virus infectivity in clinical specimens. Moreover, we define a PCR threshold value which correspond to non-infectious virus, and suggest that our data can be translated into informed decision-making regarding risk assessment, protective measures and guidelines for Monkeypox patients.

The COVID-19 pandemic caused by SARS-CoV-2 imposes an urgent need for rapid development of an efficient and cost-effective vaccine, suitable for mass immunization. Here, we show the development of a replication competent recombinant VSV-∆G-spike vaccine, in which the glycoprotein of VSV is replaced by the spike protein of SARS-CoV-2. In-vitro characterization of this vaccine indicates the expression and presentation of the spike protein on the viral membrane with antigenic similarity to SARS-CoV-2. A golden Syrian hamster in-vivo model for COVID-19 is implemented. We show that a single-dose vaccination results in a rapid and potent induction of SARS-CoV-2 neutralizing antibodies. Importantly, vaccination protects hamsters against SARS-CoV-2 challenge, as demonstrated by the abrogation of body weight loss, and alleviation of the extensive tissue damage and viral loads in lungs and nasal turbinates. Taken together, we suggest the recombinant VSV-∆G-spike as a safe, efficacious and protective vaccine against SARS-CoV-2., Here, the authors generate a replication-competent VSV based vaccine expressing SARS-CoV-2 spike protein and show protection in the hamster model with one dose. Analysis of the antibody response in mice shows induction of neutralizing antibodies and suggests a desirable Th1-biased response to the vaccine.

Both monogenic diseases and viral infections can manifest in a broad spectrum of clinical phenotypes that range from asymptomatic to lethal, suggesting that other factors modulate disease severity. Here, we examine the interplay between the genetic neuronopathic Gaucher’s disease (nGD), and neuroinvasive Sindbis virus (SVNI) infection. Infection of nGD mice with SVNI had no influence on nGD severity. However, nGD mice were more resistant to SVNI infection. Significantly different inflammatory responses were seen in nGD brains when compared with SVNI brains: the inflammatory response in the nGD brains consisted of reactive astrocytes and microglia with no infiltrating macrophages, but the inflammatory response in the brains of SVNI-infected mice was characterized by infiltration of macrophages and altered activation of microglia and astrocytes. We suggest that the innate immune response activated in nGD confers resistance against viral infection of the CNS. Electronic supplementary material The online version of this article (10.1186/s40478-020-01020-6) contains supplementary material, which is available to authorized users.

BackgroundAge/frailty are strong predictors of COVID-19 mortality. After the second BNT162b2 dose, immunity wanes faster in older (≥65 years) versus younger adults. The durability of response after the third vaccine is unclear.MethodsThis prospective cohort study included healthcare workers/family members≥60 years who received a third BNT162b2 dose. Blood samples were drawn immediately before (T0), 10□19 (T1), and 74□103 (T2) days after the third dose. Anti-spike IgG titers were determined using a commercial assay, seropositivity was defined as≥50 AU/mL. Neutralising antibody titres were determined at T2. Adverse events, COVID-19 infections, and clinical frailty scale (CFS) levels were documented.FindingsThe analysis included 97 participants (median age, 70 years [IQR, 66□74], 58% CFS level 2). IgG titres, which increased significantly from T0 to T1 (medians, 440 AU/mL [IQR, 294□923] and 25,429 [14203□36114] AU/mL, respectively; pvs T1). In a multivariable analysis, only time from the first vaccine was significantly associated with lower IgG levels at T2 (p=0·004). At T2, 60 patients were evaluated for neutralising antibodies; all were seropositive (median, 1294 antibody titre [IQR, 848□2072]). Neutralising antibody and anti-spike IgG levels were correlated (R=0·6, pInterpretationAnti-spike IgG and neutralising antibody levels remain adequate 3 months after the third BNT162b2 vaccine in healthy adults≥60 years, although the decline in IgG is concerning. A third vaccine dose in this population should be top priority.FundingNo external funding.Research in contextEvidence before this studyWe searched PubMed on Aug 1, 2021, for published research articles with no date restrictions, using the search terms of “SARS-Cov-2”, “COVID-19”, “vaccine”, “dose”, “antibody response”, and “adults” with English as a filter. Several studies were identified that investigated waning of immunity in healthy adults. It is well established through epidemiology and serology studies that in healthy adults, the protection conferred by the BNT162b2 messenger RNA (mRNA) vaccine (Pfizer/BioNtech) wanes significantly after several months. Studies have also shown that the immune response to the vaccine varies with age, and that after the second dose of the BNT162b2 vaccine, the older adult population (65-85 years of age) typically has a lower immune response (as reflected in an analysis of anti-spike IgG antibodies and neutralising antibody titres), than younger adults (18-55 years of age), and that the immunity wanes in all age groups within several months.Added value of this studyThis is, to our knowledge, the first study that examined anti-spike IgG and neutralising antibody titres three months after the third BNT162b2 vaccine dose. The study has demonstrated that three months after that dose, participants, who were healthy adults aged 60 years and older, remained anti-spike IgG seropositive, although a significant decrease in anti-spike IgG titres was observed (compared to two weeks after the third dose). In addition, a statistically significant correlation was observed between the neutralising antibody titres and the anti-spike IgG titres, and all participants were seropositive for neutralising antibodies three months after the third dose. Also, no major adverse events or COVID-19 infections were reported.Implications of all the available evidenceAs our data suggest that a third dose of the BNT162b2 vaccine is effective in maintaining adequate immune response against COVID-19 for at least several months in healthy adults aged 60 years and older, and as it is well established that older adults are at higher risk of severe COVID-19 disease and COVID-19 mortality, providing a third dose to this population should be a top priority. Our data also highlight that understanding the waning of the immune response in other age groups is key for making evidence-based policies regarding booster vaccinations for the population at large.

Summary: Liver-resident macrophages Kupffer cells (KCs) and infiltrating Ly6Chi monocytes both contribute to liver tissue regeneration in various pathologies but also to disease progression upon disruption of orderly consecutive regeneration cascades. Little is known about molecular pathways that regulate their differentiation, maintenance, or inflammatory behavior during injury. Here, we show that copper metabolism MURR1 domain (COMMD)10-deficient KCs adopt liver-specific identity. Strikingly, COMMD10 deficiency in KCs and in other tissue-resident macrophages impedes their homeostatic survival, leading to their continuous replacement by Ly6Chi monocytes. While COMMD10 deficiency in KCs mildly worsens acetaminophen-induced liver injury (AILI), its deficiency in Ly6Chi monocytes results in exacerbated and sustained hepatic damage. Monocytes display unleashed inflammasome activation and a reduced type I interferon response and acquire “neutrophil-like” and lipid-associated macrophage differentiation fates. Collectively, COMMD10 appears indispensable for KC and other tissue-resident macrophage survival and is an important regulator of Ly6Chi monocyte fate decisions and reparative behavior in the diseased liver.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of the ongoing coronavirus disease 2019 (COVID-19) pandemic. The continued spread of SARS-CoV-2 increases the probability of influenza/SARS-CoV-2 coinfection, which may result in severe disease. In this study, we examine the disease outcome of influenza A virus (IAV) and SARS-CoV-2 coinfection in K18-hACE2 mice. Our data indicate enhance susceptibility of IAV-infected mice to developing severe disease upon coinfection with SARS-CoV-2 two days later. In contrast to nonfatal influenza and lower mortality rates due to SARS-CoV-2 alone, this coinfection results in severe morbidity and nearly complete mortality. Coinfection is associated with elevated influenza viral loads in respiratory organs. Remarkably, prior immunity to influenza, but not to SARS-CoV-2, prevents severe disease and mortality. This protection is antibody-dependent. These data experimentally support the necessity of seasonal influenza vaccination for reducing the risk of severe influenza/COVID-19 comorbidity during the COVID-19 pandemic., Influenza A virus (IAV) and SARS-CoV-2 coinfection is a possible scenario during influenza season. Here, the authors show in a mouse model that IAV infection increases the risk of severe disease upon SARS-CoV-2 infection two days later. IAV vaccination, especially antibody-dependent, protects from severe disease during coinfection.

The COVID-19 pandemic initiated a worldwide race toward the development of treatments and vaccines. Small animal models included the Syrian golden hamster and the K18-hACE2 mice infected with SARS-CoV-2 to display a disease state with some aspects of human COVID-19. A group activity of animals in their home cage continuously monitored by the HCMS100 (Home cage Monitoring System 100) was used as a sensitive marker of disease, successfully detecting morbidity symptoms of SARS-CoV-2 infection in hamsters and in K18-hACE2 mice. COVID-19 convalescent hamsters rechallenged with SARS-CoV-2 exhibited minor reduction in group activity compared to naive hamsters. To evaluate the rVSV-ΔG-spike vaccination efficacy against SARS-CoV-2, we used the HCMS100 to monitor the group activity of hamsters in their home cage. A single-dose rVSV-ΔG-spike vaccination of the immunized group showed a faster recovery than the nonimmunized infected hamsters, substantiating the efficacy of rVSV-ΔG-spike vaccine. HCMS100 offers nonintrusive, hands-free monitoring of a number of home cages of hamsters or mice modeling COVID-19.

Modified vaccinia virus Ankara (MVA) was derived by repeated passaging in chick fibroblasts, during which deletions and mutations rendered the virus unable to replicate in most mammalian cells. Marker rescue experiments demonstrated that the host range defect could be overcome by replacing DNA that had been deleted from near the left end of the genome. One virus isolate, however, recovered the ability to replicate in monkey BS-C-1 cells but not human cells without added DNA, suggesting that it arose from a spontaneous mutation. Here, we showed that variants with enhanced ability to replicate in BS-C-1 cells could be isolated by blind passaging of MVA and that in each there was a point mutation leading to an amino acid substitution in the D10 decapping enzyme. The sufficiency of these single mutations to enhance host range was confirmed by constructing recombinant viruses. The D10 mutations occurred at N- or C-terminal locations distal to the active site, suggesting an indirect effect on decapping or on another previously unknown role of D10. Although increased amounts of viral mRNA and proteins were found in BS-C-1 cells infected with the mutants compared to those with parental MVA, the increases were much less than the 1- to 2-log-higher virus yields. Nevertheless, a contributing role for diminished decapping in overcoming the host range defect was consistent with increased replication and viral protein synthesis in BS-C-1 cells infected with an MVA engineered to have active-site mutations that abrogate decapping activity entirely. Optimal decapping may vary depending on the biological context. IMPORTANCE Modified vaccinia virus Ankara (MVA) is an attenuated virus that is approved as a smallpox vaccine and is in clinical trials as a vector for other pathogens. The safety of MVA is due in large part to its inability to replicate in mammalian cells. Although host range restriction is considered a stable feature of the virus, we describe the occurrence of spontaneous mutations in MVA that increase replication considerably in monkey BS-C-1 cells but only slightly in human cells. The mutants contain single nucleotide changes that lead to amino acid substitutions in one of the two decapping enzymes. Although the spontaneous mutations are distant from the decapping enzyme active site, engineered active-site mutations also increased virus replication in BS-C-1 cells. The effects of these mutations on the immunogenicity of MVA vectors remain to be determined.

rVSV-ΔG-SARS-CoV-2-S is a clinical stage (Phase 2) replication competent recombinant vaccine against SARS-CoV-2. Nonclinical safety, immunogenicity and efficacy studies were conducted in 4 animal species, using multiple dose levels (up to 108 PFU/animal) and various dosing regimens. There were no treatment related mortalities in any study, or any noticeable clinical signs. Compared to unvaccinated controls, hematology and biochemistry parameters were unremarkable and no adverse histopathological findings gave cause for safety concern in any of the studies. There was no viral shedding in urine, nor viral RNA detected in whole blood or serum samples 7 days post vaccination. The rVSV-ΔG-SARS-CoV-2-S vaccine immune response gave rise to neutralizing antibodies, cellular immune response, and increased lymphocytic cellularity in the spleen germinal centers and regional lymph node. No evidence for neurovirulence was found in C57BL/6 immune competent mice or in highly sensitive IFNAR KO mice. Vaccine virus replication and distribution in K18 hACE2 transgenic mice showed a gradual clearance from the vaccination site with no vaccine virus recovered from the lungs. The rVSV-ΔG-SARS-CoV-2-S vaccine was well tolerated locally and systemically and elicited an effective immunogenic response up to the highest dose tested, supporting further clinical development.

Background The largest West African monkeypox outbreak began September 2017, in Nigeria. Four individuals traveling from Nigeria to the United Kingdom (n = 2), Israel (n = 1), and Singapore (n = 1) became the first human monkeypox cases exported from Africa, and a related nosocomial transmission event in the United Kingdom became the first confirmed human-to-human monkeypox transmission event outside of Africa. Methods Epidemiological and molecular data for exported and Nigerian cases were analyzed jointly to better understand the exportations in the temporal and geographic context of the outbreak. Results Isolates from all travelers and a Bayelsa case shared a most recent common ancestor and traveled to Bayelsa, Delta, or Rivers states. Genetic variation for this cluster was lower than would be expected from a random sampling of genomes from this outbreak, but data did not support direct links between travelers. Conclusions Monophyly of exportation cases and the Bayelsa sample, along with the intermediate levels of genetic variation, suggest a small pool of related isolates is the likely source for the exported infections. This may be the result of the level of genetic variation present in monkeypox isolates circulating within the contiguous region of Bayelsa, Delta, and Rivers states, or another more restricted, yet unidentified source pool.

Significance Vaccines are required to control COVID-19 during the current pandemic and possibly afterward. Recombinant nucleic acids, proteins, and virus vectors that stimulate immune responses to the SARS-CoV-2 S protein have provided protection in experimental animal and human clinical trials, although questions remain regarding their ability to prevent spread and the duration of immunity. The present study focuses on replication-restricted modified vaccinia virus Ankara (MVA), which has been shown to be a safe, immunogenic, and stable smallpox vaccine and a promising vaccine vector for other infectious diseases and cancer. In a transgenic mouse model, one or two injections of recombinant MVAs that express modified forms of S inhibited SARS-CoV-2 replication in the upper and lower respiratory tracts and prevented severe disease., 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. Another rMVA in which the receptor binding domain (RBD) is flanked by the signal peptide and transmembrane domains of S was also constructed. Each modified S protein was displayed on the surface of rMVA-infected cells and was recognized by anti-RBD antibody and soluble hACE2 receptor. Intramuscular injection of mice with the rMVAs induced antibodies, which neutralized a pseudovirus in vitro and, upon passive transfer, protected hACE2 transgenic mice from lethal infection with SARS-CoV-2, as well as S-specific CD3+CD8+IFNγ+ T cells. Antibody boosting occurred following a second rMVA or adjuvanted purified RBD protein. Immunity conferred by a single vaccination of hACE2 mice prevented morbidity and weight loss upon intranasal infection with SARS-CoV-2 3 wk or 7 wk later. One or two rMVA vaccinations also prevented detection of infectious SARS-CoV-2 and subgenomic viral mRNAs in the lungs and greatly reduced induction of cytokine and chemokine mRNAs. A low amount of virus was found in the nasal turbinates of only one of eight rMVA-vaccinated mice on day 2 and none later. Detection of low levels of subgenomic mRNAs in turbinates indicated that replication was aborted in immunized animals.

PURPOSE Hepatocellular carcinoma (HCC) has well-defined environmental risk factors. In addition, epidemiologic studies have suggested hereditary risk factors. The goals of this study were to determine the rate of pathogenic and likely pathogenic (P/LP) germline variants in cancer predisposition genes in patients with HCC, possible enrichment of P/LP variants in particular genes, and potential impact on clinical management. MATERIALS AND METHODS A prospective study at a tertiary medical center enrolled 217 patients with a personal history of HCC. Multigene panel testing was performed for 134 cancer predisposition genes in all patients. The rate of P/LP variants was compared with population rates. A separate retrospective cohort included 219 patients with HCC who underwent testing at a commercial laboratory. RESULTS In the prospective cohort, P/LP germline variants were identified in 25 of 217 patients with HCC (11.5%). Four patients (1.8%) had P/LP variants in the highly penetrant cancer genes BRCA2 (n = 2), MSH6 (n = 1), and PMS2 (n = 1). In addition, multiple patients had P/LP variants in FANCA (n = 5) and BRIP1 (n = 4), which were significantly enriched in HCC compared with the general population. Detection of P/LP variants led to changes in clinical management in regard to therapy selection, screening recommendations, and cascade testing of relatives. In a separate retrospective analysis of 219 patients with HCC, 30 (13.7%) were positive for P/LP variants including 13 (5.9%) with highly penetrant genes APC (n = 2), BRCA1 (n = 1), BRCA2 (n = 6), MSH2 (n = 2), or TP53 (n = 2). CONCLUSION P/LP germline variants in cancer predisposition genes were detected in 11%-14% of patients with HCC. Inherited genetics should not be overlooked in HCC as there are important implications for precision treatment, future risk of cancers, and familial cancer risk.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause for the ongoing COVID-19 pandemic1. The continued spread of SARS-CoV-2 along with the imminent flu season increase the probability of influenza-SARS-CoV-2 dual infection which might result in a severe disease. In this study, we examined the disease outcome of influenza A virus (IAV) and SARS-CoV-2 co-infection in K18-hACE2 mice. Our data indicates that IAV-infected mice are more susceptible to develop severe disease upon co-infection with SARS-CoV-2 two days post influenza infection. This co-infection results in severe morbidity and nearly uniform fatality as compared to the non-fatal influenza disease, or the partial fatality of SARS-CoV-2 alone. Co-infection was associated with elevated influenza viral load in respiratory organs. Remarkably, prior immunity to influenza, but not to SARS-CoV-2, prevented the severe disease and mortality. These data provide an experimental support that flu intervention by prior vaccination may be valuable in reducing the risk of sever Flu - SARS-CoV-2 comorbidity, and highlight the importance of vaccination.

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. 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. Another rMVA in which the receptor binding domain (RBD) flanked by the signal peptide and transmembrane domains of S was also constructed. Each modified S protein was displayed on the surface of rMVA-infected human cells and was recognized by anti-RBD antibody and by soluble hACE2 receptor. Intramuscular injection of mice with the rMVAs induced S-binding and pseudovirus-neutralizing antibodies. Boosting occurred following a second homologous rMVA but was higher with adjuvanted purified RBD protein. Weight loss and lethality following intranasal infection of transgenic hACE2 mice with CoV-2 was prevented by one or two immunizations with rMVAs or by passive transfer of serum from vaccinated mice. One or two rMVA vaccinations also prevented recovery of infectious CoV-2 from the lungs. A low amount of virus was detected in the nasal turbinates of only one of eight rMVA-vaccinated mice on day 2 and none later. Detection of subgenomic mRNA in turbinates on day 2 only indicated that replication was abortive in immunized animals.SignificanceVaccines are required to control COVID-19 during the pandemic and possibly afterwards. Recombinant nucleic acids, proteins and virus vectors that stimulate immune responses to the CoV-2 S protein have provided protection in experimental animal or human clinical trials, though questions remain regarding their ability to prevent spread and the duration of immunity. The present study focuses on replication-restricted modified vaccinia virus Ankara (MVA), which has been shown to be a safe, immunogenic and stable smallpox vaccine and a promising vaccine vector for other infectious diseases and cancer. In a transgenic mouse model, one or two injections of recombinant MVAs that express modified forms of S inhibited CoV-2 replication in the upper and lower respiratory tracts and prevented severe disease.

Liver resident macrophages Kupffer cells (KCs) and infiltrating Ly6C(hi) monocytes both contribute to liver tissue regeneration in various pathologies, but also to disease progression upon disruption of orderly consecutive regeneration cascades. Little is known about molecular pathways that regulate their differentiation, maintenance, or their inflammatory behavior during injury. Here we show that COMMD10-deficient KCs adopt liver-specific identity. Strikingly, COMMD10-deficiency in KCs and in other tissue resident macrophages impedes their homeostatic survival, leading to their continuous replacement by Ly6C(hi) monocytes. While COMMD10-deficiency in KCs mildly worsens acetaminophen-induced liver injury (AILI), its deficiency in Ly6C(hi) monocytes results in exacerbated and sustained hepatic damage. Monocytes display unleashed inflammasome activation and reduced type I interferon response and acquire ‘neutrophil-like’ and lipid associated macrophage differentiation fates. Collectively, COMMD10 appears indispensable for KC and other tissue resident macrophage survival and is an important regulator of Ly6C(hi) monocyte fate decisions and reparative behavior in the diseased liver.

Herein we provide a living summary of the data generated during the COVID Moonshot project focused on the development of SARS-CoV-2 main protease (Mpro) inhibitors. Our approach uniquely combines crowdsourced medicinal chemistry insights with high throughput crystallography, exascale computational chemistry infrastructure for simulations, and machine learning in triaging designs and predicting synthetic routes. This manuscript describes our methodologies leading to both covalent and non-covalent inhibitors displaying protease IC50 values under 150 nM and viral inhibition under 5 uM in multiple different viral replication assays. Furthermore, we provide over 200 crystal structures of fragment-like and lead-like molecules in complex with the main protease. Over 1000 synthesized and ordered compounds are also reported with the corresponding activity in Mpro enzymatic assays using two different experimental setups. The data referenced in this document will be continually updated to reflect the current experimental progress of the COVID Moonshot project, and serves as a citable reference for ensuing publications. All of the generated data is open to other researchers who may find it of use.

The human leukocyte antigen (HLA)-bound viral antigens serve as an immunological signature that can be selectively recognized by T cells. As viruses evolve by acquiring mutations, it is essential to identify a range of presented viral antigens. Using HLA peptidomics, we are able to identify severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-derived peptides presented by highly prevalent HLA class I (HLA-I) molecules by using infected cells as well as overexpression of SARS-CoV-2 genes. We find 26 HLA-I peptides and 36 HLA class II (HLA-II) peptides. Among the identified peptides, some are shared between different cells and some are derived from out-of-frame open reading frames (ORFs). Seven of these peptides were previously shown to be immunogenic, and we identify two additional immunoreactive peptides by using HLA multimer staining. These results may aid the development of the next generation of SARS-CoV-2 vaccines based on presented viral-specific antigens that span several of the viral genes., Graphical abstract, Using HLA peptidomics, Nagler et al. identify SARS-CoV-2-derived peptides presented by highly prevalent HLA-I and HLA-II. Identified peptides are derived from various canonical and non-canonical viral ORFs, are shared between different cells, and are immunogenic. As the identified peptides are unique to SARS-CoV-2, they could potentially serve as future treatment targets.

The COVID-19 pandemic was a stark reminder that a barren global antiviral pipeline has grave humanitarian consequences. Pandemics could be prevented in principle by accessible, easily deployable broad-spectrum oral antivirals. Here we report the results of theCOVID Moonshot, a fully open-science, crowd sourced, structure-enabled drug discovery campaign targeting the SARS-CoV-2 main protease. We discovered a novel chemical series that is differentiated from current Mpro inhibitors in that it maintains a new non-covalent, non-peptidic scaffold with nanomolar potency. Our approach leveraged crowdsourcing, high-throughput structural biology, machine learning, and exascale molecular simulations and high-throughput chemistry. In the process, we generated a detailed map of the structural plasticity of the SARS-CoV-2 main protease, extensive structure-activity relationships for multiple chemotypes, and a wealth of biochemical activity data. In a first for a structure-based drug discovery campaign, all compound designs (>18,000 designs), crystallographic data (>840 ligand-bound X-ray structures), assay data (>10,000 measurements), and synthesized molecules (>2,400 compounds) for this campaign were shared rapidly and openly, creating a rich open and IP-free knowledgebase for future anti-coronavirus drug discovery.

The COVID-19 pandemic caused by SARS-CoV-2 that emerged in December 2019 in China resulted in over 7.8 million infections and over 430,000 deaths worldwide, imposing an urgent need for rapid development of an efficient and cost-effective vaccine, suitable for mass immunization. Here, we generated a replication competent recombinant VSV-ΔG-spike vaccine, in which the glycoprotein of VSV was replaced by the spike protein of the SARS-CoV-2. In vitro characterization of the recombinant VSV-ΔG-spike indicated expression and presentation of the spike protein on the viral membrane with antigenic similarity to SARS-CoV-2. A golden Syrian hamster in vivo model for COVID-19 was implemented. We show that vaccination of hamsters with recombinant VSV-ΔG-spike results in rapid and potent induction of neutralizing antibodies against SARS-CoV-2. Importantly, single-dose vaccination was able to protect hamsters against SARS-CoV-2 challenge, as demonstrated by the abrogation of body weight loss of the immunized hamsters compared to unvaccinated hamsters. Furthermore, whereas lungs of infected hamsters displayed extensive tissue damage and high viral titers, immunized hamsters’ lungs showed only minor lung pathology, and no viral load. Taken together, we suggest recombinant VSV-ΔG-spike as a safe, efficacious and protective vaccine against SARS-CoV-2 infection.

The need for antiviral drugs is real and relevant. Broad spectrum antiviral drugs have a particular advantage when dealing with rapid disease outbreaks, such as the current COVID-19 pandemic. Since viruses are completely dependent on internal cell mechanisms, they must cross cell membranes during their lifecycle, creating a dependence on processes involving membrane dynamics. Thus, in this study we examined whether the synthesis of glycosphingolipids, biologically active components of cell membranes, can serve as an antiviral therapeutic target. We examined the antiviral effect of two specific inhibitors of GlucosylCeramide synthase (GCS); (i) Genz-123346, an analogue of the FDA-approved drug Cerdelga®, (ii) GENZ-667161, an analogue of venglustat which is currently under phase III clinical trials. We found that both GCS inhibitors inhibit the replication of four different enveloped RNA viruses of different genus, organ-target and transmission route: (i) Neuroinvasive Sindbis virus (SVNI), (ii) West Nile virus (WNV), (iii) Influenza A virus, and (iv) SARS-CoV-2. Moreover, GCS inhibitors significantly increase the survival rate of SVNI-infected mice. Our data suggest that GCS inhibitors can potentially serve as a broad-spectrum antiviral therapy and should be further examined in preclinical and clinical trial. Analogues of the specific compounds tested have already been studied clinically, implying they can be fast-tracked for public use. With the current COVID-19 pandemic, this may be particularly relevant to SARS-CoV-2 infection.One Sentence SummaryAn analogue of Cerdelga®, an FDA-approved drug, is effective against a broad range of RNA-viruses including the newly emerging SARS-CoV-2.