Longitudinal changes in cell-mediated immunity after varicella-zoster virus skin test in the general population; Shozu Herpes Zoster Study: SHEZ study.

Varicella-zoster virus-specific cell-mediated immunity has been associated with the onset and severity of herpes zoster (HZ), and the administration of the HZ vaccine enhanced the immunity. However, limited data is available on the duration of cell-mediated immunity enhancement by soluble antigen of varicella-zoster virus (VZV) skin test. A prospective, community-based cohort study was conducted in Shozu County, Kagawa Prefecture, Japan. Repeated VZV skin tests containing inactivated VZV antigen and blood tests were performed on 365 subjects aged 60 years and older at baseline, 1, 2, and 3 years later. The differential immunity indices of VZV over time for cell-mediated and humoral immunity were evaluated. VZV skin test reaction and ELISpot counts increased significantly at 1, 2, and 3 years later compared to the baseline. However, humoral immunity indices did not change materially over time. Soluble antigen by VZV skin test enhanced VZV-specific cell-mediated immunity, and it persisted for at least 1 year. In addition, the inoculation with inactivated antigens every year by VZV skin test continued to enhance VZV-specific cell-mediated immunity after 2 and 3 years.

Risk of Herpes Zoster in Relation to Body Mass Index Among Residents Aged ≥50 Years: The Shozu Herpes Zoster Study.

BACKGROUND: The impact of body mass index on incidence of herpes zoster is unclear. This study investigated whether body mass index was associated with a history of herpes zoster and incidence during a 3-year follow-up, using data from a prospective cohort study in Japan. METHODS: In total, 12,311 individuals were included in the cross-sectional analysis at baseline, of whom 1,818 with a history of herpes zoster were excluded from the incidence analysis, leaving 10,493 individuals. Body mass index (kg/m2) was classified into three categories (underweight: <18.5; normal: 18.5 to <25; and overweight: ≥25). To evaluate the risk of herpes zoster, we used a logistic regression model for prevalence and a Cox proportional hazard regression model for incidence. RESULTS: Being overweight or underweight was not associated with herpes zoster prevalence at baseline. The multivariate hazard ratios of herpes zoster incidence for overweight versus normal-weight groups were 0.67 (95% confidence interval, 0.51-0.90) in all participants, and 0.57 (95% confidence interval, 0.39-0.83) in women, with no significant difference for men. CONCLUSION: Being overweight was associated with a lower incidence of herpes zoster than being normal weight in older Japanese women.

The association of family history of herpes zoster and the risk of incident herpes zoster: the SHEZ Study.

BACKGROUND: We investigated whether family histories of herpes zoster (HZ) are associated with the risk of incident HZ in a Japanese population. METHODS: A total of 12,522 Japanese residents aged ≥50 years in Shozu County participated in the baseline survey between December 2008 and November 2009 (the participation rate = 72.3%). They were interviewed at baseline by research physicians regarding the registrants' history of HZ. A self-administered questionnaire survey was conducted to evaluate the potential confounding factors. 10,530 participants without a history of HZ were followed up to ascertain the incidence of HZ during 3-years follow-up until the end of November 2012 with Japanese nationals. We estimated hazard ratios (HRs) of incident HZ according to first-degree family histories using the Cox proportional hazard regression after adjusting for age, sex, and other potential confounding factors. RESULTS: Compared to no HZ history of each family member, a history of brother or sister was associated with a higher risk of incident HZ while histories of father and mother were not. The multivariable HR (95%CI) of incident HZ for a history of brother or sister was 1.67 (1.04-2.69). When comparing to no family histories of all first-degree relatives, the multivariable HRs (95%CIs) were 1.34 (0.77-2.34) for a history of brother or sister alone, but 4.81 (1.78-13.00) for a history of mother plus brother or sister. As for the number of family histories, the multivariable HRs (95%CIs) were 1.08 (0.76-1.54) for one relative (father, mother, or brother or sister) and 2.75 (1.13-6.70) for two or more relatives. CONCLUSION: Family histories of mother plus brother or sister and two or more first-degree relatives were associated with a higher risk of incident HZ.

Infectivity assay for detection of SARS-CoV-2 in samples from patients with COVID-19.

Since the coronavirus disease 2019 (COVID-19) outbreak, laboratory diagnosis has mainly been conducted using reverse-transcription polymerase chain reaction (RT-PCR). Detecting the presence of an infectious virus in the collected sample is essential to analyze if a person can transmit infectious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, there have been no quantitative investigations conducted for infectious SARS-CoV-2 in clinical samples. Therefore, in the present study, a rapid and simple focus-forming assay using the peroxidase-antiperoxidase technique was developed to quantify infectious SARS-CoV-2 titers in 119 samples (n = 52, nasopharyngeal swabs [NPS]; n = 67, saliva) from patients with COVID-19. Furthermore, the study findings were compared with the cycle threshold (Ct) values of real-time RT-PCR. The infectious virus titers in NPS samples and Ct values were inversely correlated, and no infectious virus could be detected when the Ct value exceeded 30. In contrast, a low correlation was observed between the infectious virus titers in saliva and Ct values (r = -0.261, p = 0.027). Furthermore, the infectious virus titers in the saliva were significantly lower than those in the NPS samples. Ten days after the onset of COVID-19 symptoms, the infectious virus was undetectable, and Ct values were more than 30 in NSP and saliva samples. The results indicate that patients whose symptoms subsided 10 days after onset, with Ct values more than 30 in NSP and saliva samples, were less likely to infect others.

Comprehensive Analysis of Antibodies Induced by Vaccination with 4 Kinds of Avian Influenza H5N1 Pre-Pandemic Vaccines.

Four kinds of avian-derived H5N1 influenza virus, A/Vietnam/1194/2004 (Clade 1), A/Indonesia/5/2005 (Clade 2.1), A/Qinghai/1A/2005 (Clade 2.2), and A/Anhui/1/2005 (Clade 2.3), have been stocked in Japan for use as pre-pandemic vaccines. When a pandemic occurs, these viruses would be used as vaccines in the hope of inducing immunity against the pandemic virus. We analyzed the specificity of antibodies (Abs) produced by B lymphocytes present in the blood after immunization with these vaccines. Eighteen volunteers took part in this project. After libraries of Ab-encoding sequences were constructed using blood from subjects vaccinated with these viruses, a large number of clones that encoded Abs that bound to the virus particles used as vaccines were isolated. These clones were classified into two groups according to the hemagglutination inhibition (HI) activity of the encoded Abs. While two-thirds of the clones were HI positive, the encoded Abs exhibited only restricted strain specificity. On the other hand, half of the HI-negative clones encoded Abs that bound not only to the H5N1 virus but also to the H1N1 virus; with a few exceptions, these Abs appeared to be encoded by memory B cells present before vaccination. The HI-negative clones included those encoding broadly cross-reactive Abs, some of which were encoded by non-VH1-69 germline genes. However, although this work shows that various kinds of anti-H5N1 Abs are encoded by volunteers vaccinated with pre-pandemic vaccines, broad cross-reactivity was seen only in a minority of clones, raising concern regarding the utility of these H5N1 vaccine viruses for the prevention of H5N1 pandemics.

Anti-Influenza Virus Activity of Adlay Tea Components.

Our previous study showed anti-influenza virus activity in adlay tea prepared from adlay seeds, naked barley seeds, soybean, and cassia seeds. In this study, we evaluated the anti-influenza virus activity of each component of this tea and analyzed their active ingredients. Each component was roasted and extracted in hot water; the extracts were tested for antiviral activity and their mechanisms of action were studied. All the tea components showed antiviral activity against the H1N1 and H3N2 influenza subtypes and against influenza B. The viral stages inhibited by the components were virus adsorption and replication in proliferative process, suggesting that the action mechanisms of the components might differ from those of oseltamivir acid. Of the tea components, soybean showed the strongest activity. Therefore, we analyzed its active ingredients by liquid chromatography quadruple time-of-flight mass spectrometry (LC/qTOF-MS) and daidzein and glycitein were detected as active ingredients. Here, anti-influenza virus action of glycitein was the first report.

Sleep Shortage Is Associated With Postherpetic Neuralgia Development Through Hyperesthesia and Acute Pain Intensity: A Community-Based Prospective Cohort Study.

OBJECTIVES: There have been no community-based studies investigating the association between sleep duration and postherpetic neuralgia (PHN) development. The aim of the current study was to examine the association of sleep with herpes zoster (HZ) incidence and PHN. METHODS: In total, 12,329 residents (ages 50 to 103 years) of Shozu County, Japan, participated in our study from December 2009 to November 2010 and were followed up for 3 years. At baseline, the participants completed self-administered health questionnaires, including those on usual sleep duration. Three dermatologists diagnosed HZ on the basis of clinical symptoms and virus identification testing by polymerase chain reaction and serological tests, and evaluated pain using a modified Zoster Brief Pain Inventory survey form via telephone. We used a Cox proportional hazard regression model to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of incident HZ and PHN. We also performed mediation analysis to examine whether hyperesthesia and acute pain intensity mediated the association between sleep shortage and chronic pain intensity. RESULTS: During follow-up, 400 cases of HZ were identified. Of these, 55 participants developed PHN. Sleep duration was not associated with HZ incidence. Sleep shortage increased the risk for PHN (HR 2.02 [95% CI: 1.06 to 3.85]). Hyperesthesia and acute pain intensity mediated the association between sleep shortage and chronic pain intensity (indirect/total effect ratio = 50% mediation). CONCLUSIONS: Sleep shortage was associated with increased risk for PHN, and hyperesthesia and acute pain intensity appeared to mediate this association. Sleep shortage may be a novel risk factor for PHN.

Associations of Perceived Mental Stress, Sense of Purpose in Life, and Negative Life Events With the Risk of Incident Herpes Zoster and Postherpetic Neuralgia: The SHEZ Study.

In the present population-based prospective study, we examined the associations of psychosocial factors with the incidence of herpes zoster (HZ) and postherpetic neuralgia (PHN). Data were collected from 12,359 participants (≥50 years of age) who answered a self-completed health questionnaire in the Shozu County of Kagawa Prefecture in Japan. During a 3-year follow-up between December 2008 and November 2012, HZ and PHN were diagnosed in 400 and 79 subjects, respectively. We used Cox regression analysis to estimate hazard ratios of incident HZ and PHN according to psychosocial factors, adjusting for age, sex, histories of HZ, cancer, and diabetes, smoking and drinking habits, and time from disease onset to treatment. Men with high levels of mental stress were twice as likely to be at risk for incident HZ. The risk of incident HZ was approximately 60% lower among men and women who reported a high sense of purpose in life. Women who experienced negative life events-particularly changes in their work, living environment, and relationships-had a 2- to 3-fold higher risk of incident PHN. Psychosocial factors such as perceived mental stress, sense of purpose in life, and negative life events may contribute to the development of HZ and PHN in the general population.

Analysis of the glycoproteins of Seoul orthohantavirus strain B1 associated with fusion activity.

We analyzed two virus variants (S1 and L1) from Seoul orthohantavirus strain B1. Strain B1 produces large opaque plaques when plated on Vero E6 cell monolayers. However, although the L1 variant produced the large opaque plaques common to the strain, the variant S1 produced small clear ones on Vero E6 cells. Five days after Vero E6 cells were infected with the S1 variant, polykaryons formed spontaneously. However, the cells infected with the L1 variant did not show the formation of syncytia. An analysis of the pH dependency of the cell fusion demonstrated that the L1 variant could induce cell fusion, but only at a pH that was 0.2 units lower than the pH at which the S1 variant induced it. Sequencing of the M genome segment of the two virus variants revealed amino acid substitutions at 4 positions in the Gn and Gc gene products of the S1 variant. Two of these substitutions occurred in the extracellular domain of Gn and changed the charge of the protein. Our findings suggest that these amino acid substitutions caused the S1 variant Gn protein to induce fusion at an elevated pH.

Whole-Virion Influenza Vaccine Recalls an Early Burst of High-Affinity Memory B Cell Response through TLR Signaling.

Inactivated influenza vaccines have two formulations, whole- and split-virion types; however, how differential formulations impact their booster effects remain unknown. In this study, we demonstrate that whole-virion vaccines recall two waves of Ab responses, early T cell-independent (TI) and late T cell-dependent responses, whereas split-virion vaccines elicit the late T cell-dependent response only. Notably, higher-affinity Abs with improved neutralizing activity are provided from the early TI response, which emphasizes the important contribution of the formulation-dependent response in the protective immunity. Moreover, we show that the early TI response completely requires B cell-intrinsic TLR7 signaling, which can be delivered through viral RNAs within whole-virion vaccine. Thus, our results indicate that TLR agonists in whole-virion type improve recall Ab responses by directly targeting memory B cells, a finding with important implications for vaccine strategies aimed at the prompt recall of high-affinity neutralizing Abs.

Inhibition of influenza virus replication by adlay tea.

BACKGROUND: The present study was conducted aiming to examine the antiviral activity of adlay tea and its components against influenza viruses. We further aimed to clarify the mechanism by which these components regulate virus replication. RESULTS: Adlay tea at a concentration suitable for drinking inhibited the multiplication of influenza viruses. Moreover, our results suggest that individual components of the tea had antiviral activities against the influenza A/PR/8/34 virus. Adlay tea inhibited multiplication of the H1N1, H3N2 and B types of influenza virus, including oseltamivir-resistant viruses. In addition, adlay tea inhibited influenza infection during the periods of virus adsorption to the cell and virus replication. Adlay tea did not suppress hemagglutination inhibition or cell fusion, although it slightly inhibited virus binding to Malin Darby canine kidney cells. Furthermore, our findings suggest that the antiviral compounds included in adlay tea were ingredients other than polyphenols and that there were several types of effective compounds in adlay tea inhibiting several steps of viral replication. CONCLUSION: The results of the present study demonstrate that adlay tea had antiviral effects against influenza viruses. Our findings with respect to adlay tea suggest that the polyphenols might have a small influence on its antiviral activity and that other ingredients might have more influence. © 2017 Society of Chemical Industry.

Relationship between cell-mediated immunity to Varicella-Zoster virus and aging in subjects from the community-based Shozu Herpes Zoster study.

Age-related declines in cell-mediated immunity (CMI) are associated with the incidence and severity of Herpes Zoster (HZ) infection. However, the level of Varicella-Zoster virus (VZV)-specific CMI associated with disease onset is unclear. This study aimed to examine factors associated with VZV-specific CMI, as measured by an interferon-gamma (IFN-γ) enzyme-linked immunospot (ELISPOT) assay, in a Japanese cohort. The study enrolled 365 subjects aged 60 years and over, all of whom were taking part in the Shozu Herpes Zoster (SHEZ) study and had undergone four sets of blood and intradermal reaction tests during a 3 year follow-up period. The VZV-specific immunity profile of each subject was assessed, and linear mixed effects models were constructed to analyze IFN-γ ELISPOT results in association with a combination of factors. The model that best explained the IFN-γ ELISPOT results was selected using the Akaike Information Criteria. The best-fit model consisted of age group as the only explanatory fixed-effect variable. The model showed that VZV-specific CMI, quantified as numbers of spots on the ELISPOT assay, among subjects aged 70-79 was on average 10.30 points lower than that among subjects aged 60-69. There was no statistically significant difference between subjects aged 70-79 and those aged 80-89. Age was the only factor significantly associated with the level of VZV-specific CMI, as measured by the IFN-γ ELISPOT assay. These results may represent an important step towards quantifying the relationship between VZV-specific CMI and the onset of HZ. J. Med. Virol. 89:313-317, 2017. © 2016 Wiley Periodicals, Inc.

BK-UM in patients with recurrent ovarian cancer or peritoneal cancer: a first-in-human phase-I study.

BACKGROUND: BK-UM (CRM197) is a mutant form of diphtheria toxin and a specific inhibitor of heparin-binding epidermal growth factor-like growth factor (HB-EGF). We assessed the safety, pharmacokinetics, recommended dose, and efficacy of BK-UM in patients with recurrent ovarian cancer (OC) or peritoneal cancer (PC), and measured HB-EGF levels in serum and abdominal fluid after BK-UM administration. METHODS: Eleven patients with advanced or recurrent OC or PC were enrolled and treated with BK-UM via the intraperitoneal route. The dose was escalated (1.0, 2.0, 3.3, and 5.0 mg/m2) using a 3 + 3 design. RESULTS: Eight of 11 patients completed treatment. No dose-limiting toxicity (DLT) was experienced at dose levels 1 (1.0 mg/m2) and 2 (2.0 mg/m2). Grade 3 transient hypotension as an adverse event (defined as a DLT in the present study) was observed in two of four patients at dose level 3 (3.3 mg/m2). Treatment with BK-UM was associated with decreases in HB-EGF levels in serum and abdominal fluid in seven of 11 patients and five of eight patients, respectively. Clinical outcomes included a partial response in one patient, stable disease in five patients, and progressive disease in five patients. CONCLUSIONS: BK-UM was well tolerated at doses of 1.0 and 2.0 mg/m2, with evidence for clinical efficacy in patients with recurrent OC or PC. A dose of 2.0 mg/m2 BK-UM is recommended for subsequent clinical trials. TRIAL REGISTRATION: This trial was prospectively performed as an investigator-initiated clinical trial. The trial numbers are UMIN000001002 and UMIN000001001, with registration dates of 1/30/2008 and 2/4/2008, respectively. UMIN000001001 was registered as a trial for the continuous administration of BK-UM after UMIN000001002 .

Clinical and immunologic features of recurrent herpes zoster (HZ).

BACKGROUND: Recurrent herpes zoster (HZ) is thought to be rare, but there have been few large-scale studies of recurrent HZ. OBJECTIVE: We conducted a large-scale prospective cohort study to characterize recurrent HZ. METHODS: We examined 12,522 participants aged 50 years or older in Shozu County and followed them up for 3 years. We compared the incidence of HZ and postherpetic neuralgia, severity of skin lesions and acute pain, cell-mediated immunity, and varicella-zoster virus-specific antibody titer between primary and recurrent HZ. RESULTS: A total of 401 participants developed HZ: 341 with primary HZ and 60 with recurrent HZ. Skin lesions and acute pain were significantly milder and the incidence of postherpetic neuralgia was lower in patients aged 50 to 79 years with recurrent HZ than in those with primary HZ. Varicella-zoster virus skin test induced a stronger reaction in patients aged 50 to 79 years with recurrent HZ than in those with primary HZ. LIMITATIONS: Information on previous HZ episodes was self-reported by participants, so it could not be confirmed that they actually had a history of HZ. CONCLUSION: Recurrent HZ was associated with milder clinical symptoms than primary HZ, probably because of stronger varicella-zoster virus-specific cell-mediated immunity in the patients with recurrence.

[Results of Booster Vaccination in Children with Primary Vaccine Failure after Initial Varicella Vaccination].

In October 2014, the varicella vaccination policy in Japan was changed from a single voluntary inoculation to two routine inoculations. This paper reports the results of booster vaccination in children who did not show seroconversion after initial vaccination (i.e., primary vaccine failure : PVF) over a 7-year period prior to the introduction of routine varicella vaccination. Between November 2007 and May 2014, 273 healthy children aged between 1.1 and 14.5 years (median : 1.7 years) underwent varicella vaccination. Before and 4 to 6 weeks after vaccination, the antibody titers were measured using an immune adherence hemagglutination (IAHA) assay and a glycoprotein-based enzyme-linked immunosorbent assay (gpELISA). In addition, side reactions were examined during the four-week period after vaccination. Children who did not show IAHA seroconversion (PVF) were recommended to receive a booster vaccination, and the measurement of antibody titers and an assessment of side reactions were performed after the booster dose. In May 2015, a questionnaire was mailed to each of the 273 participants to investigate whether they had developed varicella and/or herpes zoster after vaccination. After initial vaccination, the IAHA seroconversion rate was 75% and the mean antibody titer (Log2) with seroconversion was 4.7, while the gpELISA seroconversion rate was 84% and the mean antibody titer (Log10) with seroconversion was 2.4. Among children with PVF, 54 received booster vaccination within 81 to 714 days (median : 139 days) after the initial vaccination. After booster vaccination, the IAHA seroconversion rate was 98% and the mean antibody titer (Log2) with seroconversion was 5.8. Both the seroconversion rate and the antibody titer were higher compared with the values after the initial vaccination (p < 0.01). After booster vaccination, the gpELISA seropositive rate was 100% and the mean positive antibody titer (Log 10) was 3.6 ; similar results were obtained for the IAHA assay, with a significantly higher, antibody response than that after the initial vaccination (p < 0.01). Side reactions were generally minor, including fever (≥ 37.5 degrees C), rash at the injection site, and rash at other sites. There were no significant differences in the incidences of side reactions between the initial and booster vaccinations. A total of 185 participants responded to the questionnaire (response rate : 68%), and the period between receiving the initial vaccination and their response to the questionnaire ranged from 1.0 to 7.5 years (median : 4.0 years). The prevalence of breakthrough varicella after the initial vaccination was 17% among seroconverters who did not receive booster vaccination and 14% among non-seroconverters who received booster vaccination, showing no significant difference between the two groups. In conclusion, there are no safety issues regarding the administration of a booster vaccination to children with PVF after an initial varicella vaccination, and,a good antibody response can be expected.

Conserved neutralizing epitope at globular head of hemagglutinin in H3N2 influenza viruses.

UNLABELLED: Neutralizing antibodies that target the hemagglutinin of influenza virus either inhibit binding of hemagglutinin to cellular receptors or prevent the low-pH-induced conformational change in hemagglutinin required for membrane fusion. In general, the former type of antibody binds to the globular head formed by HA1 and has narrow strain specificity, while the latter type binds to the stem mainly formed by HA2 and has broad strain specificity. In the present study, we analyzed the epitope and function of a broadly neutralizing human antibody against H3N2 viruses, F005-126. The crystal structure of F005-126 Fab in complex with hemagglutinin revealed that the antibody binds to the globular head, spans a cleft formed by two hemagglutinin monomers in a hemagglutinin trimer, and cross-links them. It recognizes two peptide portions (sites L and R) and a glycan linked to asparagine at residue 285 using three complementarity-determining regions and framework 3 in the heavy chain. Binding of the antibody to sites L (residues 171 to 173, 239, and 240) and R (residues 91, 92, 270 to 273, 284, and 285) is mediated mainly by van der Waals contacts with the main chains of the peptides in these sites and secondarily by hydrogen bonds with a few side chains of conserved sequences in HA1. Furthermore, the glycan recognized by F005-126 is conserved among H3N2 viruses. F005-126 has the ability to prevent low-pH-induced conformational changes in hemagglutinin. The newly identified conserved epitope, including the glycan, should be immunogenic in humans and may induce production of broadly neutralizing antibodies against H3 viruses. IMPORTANCE: Antibodies play an important role in protection against influenza virus, and hemagglutinin is the major target for virus neutralizing antibodies. It has long been believed that all effective neutralizing antibodies bind to the surrounding regions of the sialic acid-binding pocket and inhibit the binding of hemagglutinin to the cellular receptor. Since mutations are readily introduced into such epitopes, this type of antibody shows narrow strain specificity. Recently, however, broadly neutralizing antibodies have been isolated. Most of these bind either to conserved sites in the stem region or to the sialic acid-binding pocket itself. In the present study, we identified a new neutralizing epitope in the head region recognized by a broadly neutralizing human antibody against H3N2. This epitope may be useful for design of vaccines.

Human monoclonal antibodies broadly neutralizing against influenza B virus.

Influenza virus has the ability to evade host immune surveillance through rapid viral genetic drift and reassortment; therefore, it remains a continuous public health threat. The development of vaccines producing broadly reactive antibodies, as well as therapeutic strategies using human neutralizing monoclonal antibodies (HuMAbs) with global reactivity, has been gathering great interest recently. Here, three hybridoma clones producing HuMAbs against influenza B virus, designated 5A7, 3A2 and 10C4, were prepared using peripheral lymphocytes from vaccinated volunteers, and were investigated for broad cross-reactive neutralizing activity. Of these HuMAbs, 3A2 and 10C4, which recognize the readily mutable 190-helix region near the receptor binding site in the hemagglutinin (HA) protein, react only with the Yamagata lineage of influenza B virus. By contrast, HuMAb 5A7 broadly neutralizes influenza B strains that were isolated from 1985 to 2006, belonging to both Yamagata and Victoria lineages. Epitope mapping revealed that 5A7 recognizes 316G, 318C and 321W near the C terminal of HA1, a highly conserved region in influenza B virus. Indeed, no mutations in the amino acid residues of the epitope region were induced, even after the virus was passaged ten times in the presence of HuMAb 5A7. Moreover, 5A7 showed significant therapeutic efficacy in mice, even when it was administered 72 hours post-infection. These results indicate that 5A7 is a promising candidate for developing therapeutics, and provide insight for the development of a universal vaccine against influenza B virus.

The efficacy of inactivated West Nile vaccine (WN-VAX) in mice and monkeys.

BACKGROUND: West Nile virus (WNV) belonging to the genus Flavivirus of the family Flaviviridae causes nervous system disorder in humans, horses and birds. Licensed WNV vaccines are available for use in horses but not for humans. We previously developed an inactivated West Nile virus vaccine (WN-VAX) using a seed virus from West Nile virus (WNV NY99) that was originally isolated in New York City in 1999. In this study, we report the immunogenicity of WN-VAX in both mice and non-human primates. FINDINGS: The WN-VAX immunized mice showed protection against lethal infection with WNV NY99. The challenge test performed on mice passively immunized with serum from other mice that were previously immunized with WN-VAX confirmed that the neutralizing antibody titers of more than 1log10 protected the passively immunized mice from WNV lethal infection. Furthermore, monkeys (Macaca fascicularis) immunized three times with 2.5 µg, 5 µg or 10 µg/dose of WN-VAX exhibited neutralizing antibodies in their sera with titers of more than 2log10 after the second immunization. CONCLUSIONS: The WN-VAX was protective in mice both by active and passive immunizations and was immunogenic in monkeys. These results suggest that the vaccine developed in this study may be a potential WNV vaccine candidate for human use.

Incidences of Herpes Zoster and Postherpetic Neuralgia in Japanese Adults Aged 50 Years and Older From a Community-based Prospective Cohort Study: The SHEZ Study.

BACKGROUND: Many cross-sectional studies have examined the incidences of herpes zoster (HZ) and postherpetic neuralgia (PHN), but prospective studies in Japanese older adults are lacking. Therefore, we conducted a community-based prospective cohort study to determine the incidence in Japanese adults aged ≥50 years. METHODS: We recruited 12 522 participants from Shozu County, Kagawa Prefecture, between December 2008 and November 2009 and followed participants for 3 years. When a subject presented with symptoms suggestive of HZ, they were examined at collaborating medical institutions and cooperated with onset and recovery surveys (eg, measurement of varicella zoster virus-specific immunity and a pain survey). The hazard ratios (HRs) of HZ and PHN according to sex and age were analyzed by Cox regression analysis with a significance level of 5%. RESULTS: The incidence of HZ was 10.9/1000 person-years (men: 8.5/1000 person-years; women: 12.8/1000 person-years) and was significantly higher in women than in men (HR 1.5; 95% confidence interval, 1.2-1.8). The incidence of PHN was 2.1/1000 person-years (men: 1.7/1000 person-years; women: 2.4/1000 person-years), with no significant sex differences. A total of 19% of HZ cases progressed to PHN; no sex-specific difference in the proportion of PHN cases was observed. CONCLUSIONS: We clarified the accurate incidences of HZ and PHN in a population of Japanese older adults. These incidences increased with age. HZ incidence was higher in women than in men, while PHN incidence did not differ markedly between the sexes.

Induction of anti-influenza immunity by modified green fluorescent protein (GFP) carrying hemagglutinin-derived epitope structure.

The development of vaccination methods that can overcome the emergence of new types of influenza strains caused by escape mutations is desirable to avoid future pandemics. Here, a novel type of immunogen was designed that targeted the conformation of a highly conserved region of influenza A virus hemagglutinin (HA) composed of two separate sequences that associate to form an anti-parallel ß-sheet structure. Our previous study identified this ß-sheet region as the structural core in the epitope of a characteristic antibody (B-1) that strongly neutralizes a wide variety of strains within the H3N2 serotype, and therefore this ß-sheet region was considered a good target to induce broadly reactive immunity against the influenza A virus. To design the immunogen, residues derived from the B-1 epitope were introduced directly onto a part of enhanced green fluorescent protein (EGFP), whose surface is mostly composed of ß-sheets. Through site-directed mutagenesis, several modified EGFPs with an epitope-mimicking structure embedded in their surface were prepared. Two EGFP variants, differing from wild-type (parental) EGFP by only five and nine residues, induced mice to produce antibodies that specifically bind to H3-type HA and neutralize H3N2 virus. Moreover, three of five mice immunized with each of these EGFP variants followed by a booster with equivalent mCherry variants acquired anti-viral immunity against challenge with H3N2 virus at a lethal dosage. In contrast to conventional methods, such as split HA vaccine, preparation of this type of immunogen requires less time and is therefore expected to be quickly responsive to newly emerged influenza viral strains.