Functional properties of measles virus proteins derived from a subacute sclerosing panencephalitis patient who received repeated remdesivir treatments.

Subacute sclerosing panencephalitis (SSPE) is a rare but fatal late neurological complication of measles, caused by persistent measles virus (MeV) infection of the central nervous system. There are no drugs approved for the treatment of SSPE. Here, we followed the clinical progression of a 5-year-old SSPE patient after treatment with the nucleoside analog remdesivir, conducted a post-mortem evaluation of the patient's brain, and characterized the MeV detected in the brain. The quality of life of the patient transiently improved after the first two courses of remdesivir, but a third course had no further clinical effect, and the patient eventually succumbed to his condition. Post-mortem evaluation of the brain displayed histopathological changes including loss of neurons and demyelination paired with abundant presence of MeV RNA-positive cells throughout the brain. Next-generation sequencing of RNA isolated from the brain revealed a complete MeV genome with mutations that are typically detected in SSPE, characterized by a hypermutated M gene. Additional mutations were detected in the polymerase (L) gene, which were not associated with resistance to remdesivir. Functional characterization showed that mutations in the F gene led to a hyperfusogenic phenotype predominantly mediated by N465I. Additionally, recombinant wild-type-based MeV with the SSPE-F gene or the F gene with the N465I mutation was no longer lymphotropic but instead efficiently disseminated in neural cultures. Altogether, this case encourages further investigation of remdesivir as a potential treatment of SSPE and highlights the necessity to functionally understand SSPE-causing MeV.IMPORTANCEMeasles virus (MeV) causes acute, systemic disease and remains an important cause of morbidity and mortality in humans. Despite the lack of known entry receptors in the brain, MeV can persistently infect the brain causing the rare but fatal neurological disorder subacute sclerosing panencephalitis (SSPE). SSPE-causing MeVs are characterized by a hypermutated genome and a hyperfusogenic F protein that facilitates the rapid spread of MeV throughout the brain. No treatment against SSPE is available, but the nucleoside analog remdesivir was recently demonstrated to be effective against MeV in vitro. We show that treatment of an SSPE patient with remdesivir led to transient clinical improvement and did not induce viral escape mutants, encouraging the future use of remdesivir in SSPE patients. Functional characterization of the viral proteins sheds light on the shared properties of SSPE-causing MeVs and further contributes to understanding how those viruses cause disease.

Therapeutic targeting of measles virus polymerase with ERDRP-0519 suppresses all RNA synthesis activity.

Morbilliviruses, such as measles virus (MeV) and canine distemper virus (CDV), are highly infectious members of the paramyxovirus family. MeV is responsible for major morbidity and mortality in non-vaccinated populations. ERDRP-0519, a pan-morbillivirus small molecule inhibitor for the treatment of measles, targets the morbillivirus RNA-dependent RNA-polymerase (RdRP) complex and displayed unparalleled oral efficacy against lethal infection of ferrets with CDV, an established surrogate model for human measles. Resistance profiling identified the L subunit of the RdRP, which harbors all enzymatic activity of the polymerase complex, as the molecular target of inhibition. Here, we examined binding characteristics, physical docking site, and the molecular mechanism of action of ERDRP-0519 through label-free biolayer interferometry, photoaffinity cross-linking, and in vitro RdRP assays using purified MeV RdRP complexes and synthetic templates. Results demonstrate that unlike all other mononegavirus small molecule inhibitors identified to date, ERDRP-0519 inhibits all phosphodiester bond formation in both de novo initiation of RNA synthesis at the promoter and RNA elongation by a committed polymerase complex. Photocrosslinking and resistance profiling-informed ligand docking revealed that this unprecedented mechanism of action of ERDRP-0519 is due to simultaneous engagement of the L protein polyribonucleotidyl transferase (PRNTase)-like domain and the flexible intrusion loop by the compound, pharmacologically locking the polymerase in pre-initiation conformation. This study informs selection of ERDRP-0519 as clinical candidate for measles therapy and identifies a previously unrecognized druggable site in mononegavirus L polymerase proteins that can silence all synthesis of viral RNA.

MMR vaccination timing and long-term immunity among childhood cancer survivors.

Long-term seroprotection against the measles and mumps viruses has not been reported in childhood cancer survivor (CCS) who received two-lifetime doses of the measles, mumps, and rubella (MMR) vaccine. We performed a retrospective study of measles and mumps titers among 55 CCS who received standard chemotherapy and two MMR vaccinations at any time. Over 75% of CCS who received at least one MMR prior to their cancer diagnosis had a negative or equivocal titer to measles or mumps. In contrast, all CCS who received the MMR series following their cancer treatment demonstrated long-term seroprotection to both viruses at a mean of 8.2 years after their last vaccination.

Intralesional measles, mumps, and rubella vaccine after failure of intralesional Candida antigen for the treatment of recalcitrant pediatric warts.

Numerous studies have investigated the efficacy of intralesional immunotherapy for warts, but there are a lack of studies investigating the efficacy of alternative intralesional immunotherapies following failure of initial intralesional immunotherapy. In this retrospective study, we aimed to investigate the efficacy of intralesional measles, mumps, and rubella vaccine for the treatment of pediatric warts following failure of intralesional therapy with Candida antigen. Following intralesional measles, mumps, and rubella vaccine administration, 8/51 (15.5%) patients had complete resolution of their warts, 6/51 (12%) had near complete resolution, 19/51 (37%) had partial improvement, 12/51 (23.5%) had no change, and 6/51 (12%) had worsening. Although limited by retrospective nature and low sample size, our results demonstrate that intralesional immunotherapy with measles, mumps, and rubella vaccine provides an alternative therapeutic option for the treatment of recalcitrant pediatric warts in patients who fail to respond to intralesional Candida antigen.

A comparative evaluation of therapeutic response in warts to intralesional vitamin D3 versus intralesional measles, mumps, and rubella vaccine.

The infection of keratinocytes by human papilloma virus (HPV) causes warts. These are of different types based on morphological and anatomical grounds. This has led to the development of strategies involved in the treatment of warts by induction of delayed hypersensitivity reactions. The current study aims to compare the therapeutic response and side effect profile of intralesional vitamin D3 and measles, mumps, and rubella (MMR). The aim of this study is to study the therapeutic response of two intralesional immunotherapies in warts and compare their efficacies and side effects. A single-blind randomized control trial was conducted over 12 months on 100 patients using the purposive sampling technique. Randomly, half of the participants received one of the two immunotherapies. The clinical response was evaluated on the basis of decrease in wart size, wart number, wart distribution, and photographic comparison. The mean size of the largest wart in the vitamin D3 group was found to be 0.70 cm, and in the MMR group, it was 0.79 cm in breadth. The mean onset of first response was 3.55 weeks in the vitamin D3 group and 3.85 weeks in the MMR group. Complete response was seen in 54% and 62% of study participants in the vitamin D3 and MMR groups respectively. The study recommends that both intralesional vitamin D3 and MMR are efficacious in treating cutaneous warts, with MMR agents being moderately better compared to vitamin D3 in terms of warts clearance and side effects profile.

The Plant-Derived Naphthoquinone Droserone Inhibits In Vitro Measles Virus Infection.

The naphthoquinone droserone (1) is a natural product occurring in dicotyledonous plants. We have now observed that the addition of 1 during infection of tissue culture cells with measles virus considerably reduced the infection. Interestingly, the infection was inhibited only when droserone (1) was added during virus entry, but not when added to the cells prior to virus uptake or after virus uptake. These findings suggest that 1 interacts with viral particles to reduce infectivity. The formation of progeny measles virus particles was inhibited to 50 % by droserone (1) at a concentration (IC50) of approximately 2 µM with a half-maximal cytotoxicity (CC50) of about 60 µM for Vero cells. Other tested naphthoquinone derivatives, among them the likewise natural plumbagin (2), but also synthetic analogs, were either more cytotoxic or not as effective as 1. Thus, our data do not support the development of naphthoquinone derivatives into antiviral compounds, but suggest that they may be interesting research tools to study measles virus entry into cells.

Fatal measles virus infection prevented by brain-penetrant fusion inhibitors.

Measles virus (MV) infection causes an acute childhood disease that can include infection of the central nervous system and can rarely progress to severe neurological disease for which there is no specific treatment. We generated potent antiviral peptide inhibitors of MV entry and spreading and MV-induced cell fusion. Dimers of MV-specific peptides derived from the C-terminal heptad repeat region of the MV fusion protein, conjugated to cholesterol, efficiently protect SLAM transgenic mice from fatal MV infection. Fusion inhibitors hold promise for the prophylaxis of MV infection in unvaccinated and immunocompromised people, as well as potential for the treatment of grave neurological complications of measles.

Measles outbreak in a pediatric oncology unit and the role of ribavirin in prevention of complications and containment of the outbreak.

The role of oral ribavirin in treatment and containment of a measles outbreak in 15 children in an oncology unit is presented. Measles was diagnosed on clinical features and history of contact. Measles specific IgM ELISA and RNA were positive in 7 of 15 and 2 of 7 tested children, respectively. Duration of illness was longer in unimmunized as compared to immunized children (P = 0.02). Complications were higher in hematological malignancies (P = 0.025). Delay in starting ribavirin was associated with fatal complications (2 of 2 vs. 0 of 13, P = 0.009). Ribavirin prevented measles in all (21 of 21) patients exposed to the cases.

Effect of remdesivir post-exposure prophylaxis and treatment on pathogenesis of measles in rhesus macaques.

Measles is a systemic disease initiated in the respiratory tract with widespread measles virus (MeV) infection of lymphoid tissue. Mortality can be substantial, but no licensed antiviral therapy is available. We evaluated both post-exposure prophylaxis and treatment with remdesivir, a broad-spectrum antiviral, using a well-characterized rhesus macaque model of measles. Animals were treated with intravenous remdesivir for 12 days beginning either 3 days after intratracheal infection (post-exposure prophylaxis, PEP) or 11 days after infection at the onset of disease (late treatment, LT). As PEP, remdesivir lowered levels of viral RNA in peripheral blood mononuclear cells, but RNA rebounded at the end of the treatment period and infectious virus was continuously recoverable. MeV RNA was cleared more rapidly from lymphoid tissue, was variably detected in the respiratory tract, and not detected in urine. PEP did not improve clinical disease nor lymphopenia and reduced the antibody response to infection. In contrast, LT had little effect on levels of viral RNA or the antibody response but also did not decrease clinical disease. Therefore, remdesivir transiently suppressed expression of viral RNA and limited dissemination when provided as PEP, but virus was not cleared and resumed replication without improvement in the clinical disease parameters evaluated.

Measles, mumps, and rubella.

Measles, mumps, and rubella are viral diseases that may adversely affect nonimmune pregnant women and their fetuses/neonates. Prevention of these diseases and their complications can be achieved through measles-mumps-rubella (MMR) vaccination before pregnancy. The vaccine is contraindicated during pregnancy, because it contains live, attenuated viruses that pose a theoretical risk to the fetus. However, accidental receipt of MMR vaccination is not known to cause maternal/fetal complications. MMR immunization is recommended to nonimmune obstetric patients upon completion or termination of pregnancy.

Measles in rural West Bengal, India, 2005-6: low recourse to the public sector limits the use of vitamin A and the sensitivity of surveillance.

BACKGROUND: Measles is often underreported. We evaluated the sensitivity of the measles surveillance in 2 districts of West Bengal in 2005-2006. METHODS: We sampled households with children aged <5 years in village clusters selected with probability proportional to size. We searched households door to door to identify World Health Organization-defined suspected measles cases that had occurred during 12 months in 2004-2005 in Howrah and in 2006 in Purulia. We interviewed mothers about use of health care services during episodes and calculated the proportion of patients seen in the public sector. We reviewed surveillance records at all levels to estimate the proportion of cases seen in public health care facilities that had been reported to the district. We calculated the overall sensitivity of measles surveillance by multiplying these 2 proportions. RESULTS: In Howrah, we identified 240 cases of measles. Of these, 8 (3.3% [95% confidence interval {CI}, 1.5%-6.5%]) had been seen in public facilities and recorded. Of 980 cases identified in 448 public facilities in the periphery, 962 (98%) had been transmitted to the district (overall sensitivity of surveillance, 3.2%). In Purulia, we identified 167 measles cases. Of these, 39 (23.4% [95% CI, = 17.2%-30.5%]) had been seen in public facilities and recorded. Of 418 cases identified in public facilities in the periphery, 414 (99%) had been transmitted to the district (overall sensitivity of surveillance, 23.1%). CONCLUSIONS: Measles surveillance captured a minority of measles cases, but cases captured were transmitted well to the district. Surveillance must engage the private sector. Health education focusing on vitamin A treatment for measles might provide an incentive to seek care, which could increase the sensitivity of surveillance.

Innovations in vaccine delivery: increasing access, coverage, and equity and lessons learnt from measles and rubella elimination.

Disease eradication and elimination programs drive innovations based on progress toward measurable objectives, evaluations of new strategies and methods, programmatic experiences, and lessons learned from the field. Following progress toward global measles elimination, reducing measles mortality, and increasing introductions of measles and rubella vaccines to national programs, the measles and rubella immunization program has faced setbacks in recent years. Currently available vaccine delivery methods have complicated logistics and drawbacks that create barriers to vaccination; innovations for easier, more efficient, and safer vaccine delivery are needed. Progress can be accelerated by new technologies like microarray patches (MAPs) that are now widely recognized as a potential new tool for enhancing global immunizations efforts. Clinical trials of measles-rubella vaccine MAPs have begun, and several other vaccine MAPs are in the pre-clinical development pathway. MAPs could significantly contribute to Immunization Agenda 2030 priorities, including reaching zero-dose children; increasing vaccine access, demand, coverage, and equity; and achieving measles and rubella elimination. With strong partnerships between public health agencies and biotechnology companies, translational novel vaccine delivery systems can be developed to help solve public health problems and achieve global health priorities.

Chinese medicinal herbs for measles.

BACKGROUND: Measles is an infectious disease caused by the Morbillivirus. Chinese physicians believe that medicinal herbs are effective in alleviating symptoms and preventing complications. Chinese herbal medicines are dispensed according to the particular symptoms. This is the second update of a Cochrane Review first published in 2006. OBJECTIVES: To assess the effectiveness and possible adverse effects of Chinese medicinal herbs for measles. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Clinical Trials (CENTRAL Issue 1, 2011) which contains the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE (1966 to March week 5, 2011), EMBASE (1980 to April 2011), Web of Science (2005 to 30 April 2011), AMED (1985 to 30 April 2011), Chinese Biomedical Database (1976 to 30 June 2011), VIP Information (1989 to 30 June 2011), China National Knowledge Infrastructure (CNKI) (1976 to 30 June 2011), Chinese Journals full-article database (1994 to 30 June 2011) and the metaRegister of Controlled Trials for ongoing trials. SELECTION CRITERIA: Randomised controlled trials (RCTs) of Chinese medicinal herbs in patients with measles (without complications). DATA COLLECTION AND ANALYSIS: Two review authors (SC, TW) independently assessed trial quality and extracted data. We telephone interviewed the trial authors for missing information regarding participant allocation. Some trials allocated participants according to the sequence they were admitted to the trials, that is to say, by using a pseudo-random allocation method. None of the trials concealed the allocation or used blinding methods. MAIN RESULTS: We did not identify any suitable trials for inclusion. In this updated review we identified 80 trials which claimed to use random allocation. We contacted 32 trial authors by telephone and learned that the allocation methods used were not randomised. We excluded 34 studies because the participants experienced complications such as pneumonia. We excluded 10 trials because of non-random allocation and complications experienced by the participants. We were unable to contact the remaining four trials' authors, so they require further assessment and have been allocated to the 'Studies awaiting classification' section. AUTHORS' CONCLUSIONS: There is no RCT evidence for or against Chinese medicinal herbs as a treatment for measles. We hope high-quality, robust RCTs in this field will be conducted in the future.

Vitamin A in Children Hospitalized for Measles in a High-income Country.

BACKGROUND: Worldwide medical authorities recommend vitamin A supplementation for severe measles requiring hospitalization; however, evidence supporting its use in high-income countries is lacking. A nationwide vitamin A shortage reported in concomitance with a recent measles outbreak in Italy provided an opportunity to test the effectiveness of vitamin A in a high-income setting, approximating an unbiased allocation. METHODS: We conducted a prospective controlled cohort study involving children admitted for measles to a tertiary-care hospital in Southern Italy. The primary outcome was the duration of fever. Secondary outcomes included the length of hospitalization, rate of complications, need for antibiotic treatment and body temperature. RESULTS: A total of 108 inpatient children (36% female, median age 16.3 months) were enrolled; 36 received 2 doses of oil-based vitamin A according to age, and 72 matched controls received standard care. There were no significant differences between the study groups in the duration of fever (7.03 ± 2.67 vs. 6.82 ± 3.27, P = 0.72), length of hospitalization (median, 5.0 vs. 5.0 days, P = 0.50), maximum body temperature (median, 39°C in both groups, P = 0.23), rate of organ (69.4% vs. 63.9%, P = 0.72) and hematologic complications (41.7% vs. 59.7%, P = 0.12), or need for antibiotic treatment (66.7% vs. 61.1%, P = 0.72). Overall, vitamin A supplementation did not reduce the risk of any complications (relative risk, 1.33; 95% confidence intervals: 0.59-2.96). CONCLUSION: Vitamin A does not change the clinical course of measles infection or the rate of complications in children hospitalized in a high-income country. STUDY REGISTRATION NUMBER: EU PAS 31805.

Favorable outcomes of interferon-α and ribavirin treatment for a male with subacute sclerosing panencephalitis.

Subacute sclerosing panencephalitis (SSPE) is a slow virus infection associated with mutant measles virus (MeV). The long-term outcome of antiviral treatments remains to be determined. We herein present a Japanese boy who was diagnosed with SSPE at 10 years of age. Intraventricular infusions of interferon-α effectively prevented the progress of symptoms during 14 years of follow-up period. Flow-cytometric analysis demonstrated higher proportion of T helper 17 cells (Th17, 18.2%) than healthy controls (4.8-14.5%) despite the normal subpopulation of peripheral lymphocytes. These data suggest that a group of patients with SSPE may show favorable responses to intraventricular infusions of interferon-α.

Antiviral Effect of Favipiravir (T-705) against Measles and Subacute Sclerosing Panencephalitis Viruses.

Subacute sclerosing panencephalitis (SSPE) is a late-onset, intractable, and fatal viral disease caused by persistent infection of the central nervous system with a measles virus mutant (SSPE virus). In Japan, interferon-α and ribavirin are administered intracerebroventricularly to patients with SSPE. However, as the therapeutic effect is insufficient, more effective drugs are needed. Favipiravir, which is clinically used as an anti-influenza drug, demonstrates anti-viral effects against RNA viruses. In this study, the antiviral effect of favipiravir against measles virus (Edmonston strain) and SSPE virus (Yamagata-1 strain) was examined in vitro. The 50% effective concentration (EC50) of favipiravir (inhibiting viral plaque formation by 50%) against Edmonston and Yamagata-1 strains were 108.7 ± 2.0 µM (17.1 ± 0.3 µg/mL) and 38.6 ± 6.0 µM (6.1 ± 0.9 µg/mL), respectively, which were similar to those of ribavirin. The antiviral activity of favipiravir against the SSPE virus was demonstrated for the first time in this study.

Clearance of measles virus from persistently infected cells by short hairpin RNA.

Subacute sclerosing panencephalitis (SSPE) is a demyelinating central nervous system disease caused by a persistent measles virus (MV) infection of neurons and glial cells. There is still no specific therapy available, and in spite of an intact innate and adaptive immune response, SSPE leads inevitably to death. In order to select effective antiviral short interfering RNAs (siRNAs), we established a plasmid-based test system expressing the mRNA of DsRed2 fused with mRNA sequences of single viral genes, to which certain siRNAs were directed. siRNA sequences were expressed as short hairpin RNA (shRNA) from a lentiviral vector additionally expressing enhanced green fluorescent protein (EGFP) as an indicator. Evaluation by flow cytometry of the dual-color system (DsRed and EGFP) allowed us to find optimal shRNA sequences. Using the most active shRNA constructs, we transduced persistently infected human NT2 cells expressing virus-encoded HcRed (piNT2-HcRed) as an indicator of infection. shRNA against N, P, and L mRNAs of MV led to a reduction of the infection below detectable levels in a high percentage of transduced piNT2-HcRed cells within 1 week. The fraction of virus-negative cells in these cultures was constant over at least 3 weeks posttransduction in the presence of a fusion-inhibiting peptide (Z-Phe-Phe-Gly), preventing the cell fusion of potentially cured cells with persistently infected cells. Transduced piNT2 cells that lost HcRed did not fuse with underlying Vero/hSLAM cells, indicating that these cells do not express viral proteins any more and are "cured." This demonstrates in tissue culture that NT2 cells persistently infected with MV can be cured by the transduction of lentiviral vectors mediating the long-lasting expression of anti-MV shRNA.

Current animal models: cotton rat animal model.

The cotton rat (Sigmodon hispidus) model has proven to be a suitable small animal model for measles virus pathogenesis to fill the niche between tissue culture and studies in macaques. Similar to mice, inbred cotton rats are available in a microbiologically defined quality with an ever-increasing arsenal of reagents and methods available for the study of infectious diseases. Cotton rats replicate measles virus in the respiratory tract and (depending on virus strain) in lymphoid organs. They can be infected with vaccine, wild-type, and recombinant measles viruses and have been used to study viruses with genetic modifications. Other areas of study include efficacy testing of antivirals and vaccines. The cotton rat also has been an informative animal model to investigate measles virus-induced immune suppression and suppression of vaccination by maternal antibodies. In addition, the cotton rat promises to be a useful model for the study of polymicrobial disease (interaction between measles virus and secondary pathogens).

Short hairpin RNA-mediated inhibition of measles virus replication in vitro.

Rab9 has been identified as a key component for the replication of measles virus (MV). In this study, gene-specific shRNAs were developed to suppress the replication of MV in culture cells by silencing the expression of Rab9 GTPase gene. Rab9 GTPase gene-specific shRNAs were designed and cloned into the expression vector of pSUPER.neo+EGFP. Vero-E6 cells were transfected with the recombinant plasmid via liposome and then infected with MV. The expression of Rab9 GTPase mRNA and protein were assayed by RT-PCR and Western blotting, respectively. ShRNA-mediated inhibition of MV replication was further evaluated by detecting the titer of MV. The results showed that the expression of Rab9 GTPase was dramatically and stably downregulated by the generated shRNAs targeting Rab9 GTPase gene, which contribute to the inhibition of MV replication, indicating these shRNAs could be potentially developed into therapeutic agents for the treatment of MV infection in the future.