Seroprevalence of herpes simplex virus 1 and 2 in a population-based cohort in Japan

The association between alcohol consumption and herpes simplex virus type 2: A cross-sectional study from national health and nutrition examination survey 2009-2016

BACKGROUND

The current prevalence of Herpes simplex virus type 2 (HSV-2) infection is notably high, with individuals afflicted by HSV-2 facing recurrent outbreaks, challenges in achieving remission, and an elevated risk of HIV infection. This study aims to investigate the relationship between alcohol consumption and HSV-2 infection.

METHODS

The data for this study were sourced from 7257 participants who took part in the National Health and Nutrition Examination Survey (NHANES) from 2009 to 2016. The target population consisted of adults with reliable HSV-2 plasma results, and alcohol consumption was assessed using self-report methods. We evaluated the odds ratio (OR) and 95% confidence interval (CI) for the association between alcohol consumption and HSV-2 infection. These estimations were derived from a logistic regression model that was adjusted for key confounding factors. Subgroup analysis specifically focused on alcohol consumption, and the interaction between HSV-2 infection, alcohol consumption, and other variables was assessed through stratified analysis.

RESULTS

Among the 7,257 participants included, 89.8% (6,518/7,257) reported varying levels of alcohol consumption history. Compared to individuals who never drinkers, the adjusted odds ratios (ORs) for former drinkers, light drinkers, moderate drinkers, and heavy drinkers were 1.79 (95% CI: 1.34-2.4, p < 0.001), 1.38 (95% CI: 1.07-1.77, p = 0.012), 1.49 (95% CI: 1.15-1.94, p = 0.003), and 1.47 (95% CI: 1.14-1.9, p = 0.003), respectively. The results remained stable in subgroup analyses and sensitivity analyses.

CONCLUSION

Current research indicates that individuals with a history of alcohol consumption exhibit a higher risk of HSV-2 infection compared to those who have never drinkers.

Contribution of CNS and extra-CNS infections to neurodegeneration: a narrative review

Central nervous system infections have been suggested as a possible cause for neurodegenerative diseases, particularly sporadic cases. They trigger neuroinflammation which is considered integrally involved in neurodegenerative processes. In this review, we will look at data linking a variety of viral, bacterial, fungal, and protozoan infections to Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis and unspecified dementia. This narrative review aims to bring together a broad range of data currently supporting the involvement of central nervous system infections in the development of neurodegenerative diseases. The idea that no single pathogen or pathogen group is responsible for neurodegenerative diseases will be discussed. Instead, we suggest that a wide range of susceptibility factors may make individuals differentially vulnerable to different infectious pathogens and subsequent pathologies.

Low Prevalence of HSV-1 and Helicobacter pylori in HNSCC and Chronic Tonsillitis Patients Compared to Healthy Individuals

Recent studies identified viral and bacterial factors, including HSV-1 and H. pylori, as possible factors associated with diseases such as chronic tonsillitis and cancers, including head and neck squamous cell carcinoma (HNSCC). We assessed the prevalence of HSV-1/2 and H. pylori in patients with HNSCC, chronic tonsillitis, and healthy individuals using PCR after DNA isolation. Associations were sought between the presence of HSV-1, H. pylori, and clinicopathological and demographic characteristics and stimulant use. HSV-1 and H. pylori were most frequently identified in controls (HSV-1: 12.5% and H. pylori: 6.3%). There were 7 (7.8%) and 8 (8.6%) patients with positive HSV-1 in HNSCC and chronic tonsillitis patients, respectively, while the prevalence of H. pylori was 0/90 (0%) and 3/93 (3.2%), respectively. More cases of HSV-1 were observed in older individuals in the control group. All positive HSV-1 cases in the HNSCC group were associated with advanced tumor stage (T3/T4). The prevalence of HSV-1 and H. pylori was highest in the controls compared to HNSCC and chronic tonsillitis patients, which indicates that the pathogens were not risk factors. However, since all positive HSV-1 cases in the HNSCC group were observed only in patients with advanced tumor stage, we suggested a possible link between HSV-1 and tumor progression. Further follow-up of the study groups is planned.

Herpes simplex virus DNA testing by a loop-mediated isothermal amplification method for accurate clinical diagnosis and detection of mucosal viral shedding

Herpes simplex virus (HSV) periodically forms characteristic blisters in the perioral and genital areas in a subset of people. Because of the lack of accurate tests for this common virus, various types of perioral/anogenital lesions are often misdiagnosed as herpes. Also, though asymptomatic HSV-positive people shed virus, the precise time course of symptoms and viral shedding is unclear. The loop-mediated isothermal amplification (LAMP) method amplifies target DNA sequences without thermal cycles, simpler and faster than polymerase chain reaction (PCR). To investigate clinico-laboratorial correlation and whether HSV can be detected in the oral cavity during symptom occurrence, we collected 445 specimens from 211 patients who visited our clinic with suspected herpetic lesions or non-symptomatic volunteers. DNA was extracted from swabs simultaneously taken from lesions (n = 219) and seemingly asymptomatic oral mucosa (n = 226). HSV-1 and HSV-2 DNA sequences were amplified by LAMP and validated by quantitative real-time PCR. The LAMP method detected HSV DNA almost as sensitively (97%) as PCR. Positivity for HSV DNA was found in 54% (40/74) of specimens from the perioral/oral area. Review of clinical images of recurrent herpes labialis revealed that HSV DNA was detected only from lesions located on the perioral skin and/or the dry, vermillion part of the lip; no HSV DNA was found in immunocompetent patients with lesions confined to the oral mucosa except primary infection. This observation may be an important principle for clinical diagnosis of recurrent herpes. HSV was detected in the oral mucosa in 2.7% (6/226) of samples; all of these patients had either primary infection or were immunosuppressed. Virus shedding in the mucosa was apparently tightly regulated by the immune system. Patients with suppressed or no immunity (naïve cases) did shed virus in the mucosa. LAMP is a simple method to reliably distinguish recurrent/primary herpes from other conditions.

The association between herpes simplex virus type 1 infection and Alzheimer's disease

There is growing evidence demonstrating the relationship between herpes simplex virus type 1 (HSV-1) infection and Alzheimer's disease (AD). We searched PubMed, Embase, and Cochrane databases for relevant articles. The Newcastle-Ottawa Scale (NOS) was used to evaluate the qualities of these studies. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random-effects models. We also performed subgroup analyses stratified by apolipoprotein ε4 (APOE ε4), NOS score, and the method of confirming AD. A total of 21 studies between 1990 and 2020 were identified. The pooled OR suggested that HSV-1 infection is a risk factor of AD: pooled OR 1.40 (95% CI: 1.13-1.75; I² = 3%, P = 0.42). In the subgroup analyses, the pooled ORs of HSV-1 infection associated with AD were 0.75 (95% CI: 0.24-2.37) among the APOE ε4-positive individuals; 0.85 (95% CI: 0.61-1.17) among the APOE ε4-negative individuals; 1.51 (95% CI: 1.10-2.06) in the high NOS score studies; 1.23 (95% CI: 0.85-1.76) in the moderate NOS score studies; 1.47 (95% CI: 1.16-1.87) in the clinical diagnosis group, and 1.20 (95% CI: 0.77-1.87) in the autopsy group. Our up-to-date systematic review and meta-analysis suggest that HSV-1 infection is a risk factor of AD.

The Epidemiology of Herpes Simplex Virus Type 1 in Asia: Systematic Review, Meta-analyses, and Meta-regressions

Background

Herpes simplex virus type 1 (HSV-1) epidemiology in Asia was characterized by assessing seroprevalence levels and extent to which HSV-1 is isolated from clinically diagnosed genital ulcer disease (GUD) and genital herpes.

Methods

HSV-1 reports in Asia were systematically reviewed and synthesized, following PRISMA guidelines. Random-effects meta-analyses estimated pooled mean seroprevalence and proportion of HSV-1 detection in GUD and genital herpes. Random-effects meta-regressions identified predictors of seroprevalence and sources of between-study heterogeneity.

Results

Forty-nine relevant publications were identified. Fifty-four overall seroprevalence measures (182 stratified measures), and 8 and 24 proportions of HSV-1 detection in GUD and in genital herpes, respectively, were extracted. The pooled mean seroprevalence was 50.0% (n = 26; 95% confidence interval [CI], 41.3%–58.7%) for children and 76.5% (n = 151; 73.3%–79.6%) for adults. By age group, the pooled mean was lowest at 55.5% (n = 37; 95% CI, 47.5%–63.4%) in individuals aged <20 years, followed by 67.9% (n = 48; 62.4%–73.3%) in those aged 20–39 and 87.5% (n = 44; 83.4%–91.1%) in those aged ≥40 years. In meta-regression, age was the major predictor of seroprevalence. The mean proportion of HSV-1 detection was 5.6% (n = 8; 95% CI, 0.8%–13.6%) in GUD and 18.8% (n = 24; 12.0%–26.7%) in genital herpes.

Conclusions

HSV-1 epidemiology is transitioning in Asia. HSV-1 is probably playing a significant role as a sexually transmitted infection, explaining one-fifth of genital herpes cases. There is a need for expanded seroprevalence monitoring and GUD/genital herpes etiological surveillance.

Current Antivirals and Novel Botanical Molecules Interfering With Herpes Simplex Virus Infection

Herpes simplex viruses type 1 (HSV-1) and type 2 (HSV-2) are highly prevalent within the human population and are characterized by lifelong infections and sporadic recurrences due to latent neuron infection. Upon reactivations, HSVs may manifest either, symptomatically or asymptomatically and be shed onto others through mucosae body fluids. Although, HSVs can produce severe disease in humans, such as life-threatening encephalitis and blindness, the most common symptoms are skin and mucosal lesions in the oro-facial and the genital areas. Nucleoside analogs with antiviral activity can prevent severe HSV infection, yet they are not very effective for treating skin manifestations produced by these viruses, as they only reduce in a few days at most the duration of lesions. Additionally, HSV variants that are resistant to these antivirals may arise, especially in immunosuppressed individuals. Thus, new antivirals that can reduce the severity and duration of these cutaneous manifestations would certainly be welcome. Here, we review currently available anti-herpetic therapies, novel molecules being assessed in clinical trials and new botanical compounds reported in the last 20 years with antiviral activities against HSVs that might represent future treatments against these viruses.

Carbazole Derivatives as Antiviral Agents: An Overview

Keywords: carbazole; tetrahydrocarbazole; antiviral agents.

Aging-associated latent herpes viral infection in normal Japanese individuals and patients with Werner syndrome

A series of our "inflammageing" study examining serum samples from a maximum of 217 healthy Japanese individuals aged between 1 and 100 years and mutation-proven 40 patients with Werner syndrome (WS) indicated normal aging-associated elevations of highly sensitive CRP (hsCRP) and matrix metalloproteinase-9 (MMP-9). To further study the contribution of environmental factors such as persistent herpes viral infection to inflammageing, IgG antibodies against varicella/zoster virus (VZV) and cytomegalovirus (CMV) were examined in the same serum samples as has been done for hsCRP and MMP-9 analyses. The mean levels of serum IgG viral antibodies were comparable between normal (mean ± SE: 31.0 ± 4.3 unit) and WS (38.6 ± 7.6) for CMV, and between normal (42.0 ± 12.2) and WS (29.8 ± 3.8) for VZV, respectively. Significant associations of aging with IgG anti-CMV antibody were in normal aging (p = 0.023) and WS (p = 0.037), but not with IgG VZV in both conditions. Aging-associated change of IgG anti-CMV antibody titer in WS increased significantly (1.32 times higher) compared with normal aging (p = 0.037). IgG anti-CMV level was significantly elevated in the male gender than female in both conditions (p = 0.006). Elevated hsCRP level was significantly associated with IgG anti-CMV (p = 0.016) and IgG anti-VZV (p = 0.008) antibodies in normal aging, but not in WS. Serum MMP-9 was significantly associated with IgG anti-CMV level (p = 0.0002) in normal aging, but not in WS. Persistent herpes viral infection may constitute a part of "inflammageing" in normal aging and WS.

Association of the Emergence of Acyclovir-Resistant Herpes Simplex Virus Type 1 With Prognosis in Hematopoietic Stem Cell Transplantation Patients

Background

Antiviral-resistant herpes simplex virus type 1 (HSV-1) has been recognized as an emerging clinical problem among patients undergoing hematopoietic stem cell transplantation (HSCT).

Methods

A prospective observational study was conducted at a hematological center over a 2-year period. Oropharyngeal swab samples were serially collected each week from 1 week before and up to 100 days after HSCT and were tested for virus isolation. The HSV-1 isolates were tested for sensitivity to acyclovir (ACV). The prognosis of patients with ACV-resistant (ACVr) HSV-1 and the genetic background of the ACVr HSV-1 isolates were assessed.

Results

Herpes simplex virus type 1 was isolated in 39 of 268 (15%) HSCT patients within 100 days after transplantation. Acyclovir-resistant HSV-1 emerged in 11 of these 39 patients (28%). The 100-day death rates of HSCT patients without HSV-1 shedding, those with only ACV-sensitive HSV-1 shedding, and those with ACVr HSV-1 shedding were 31%, 39%, and 64%, respectively. Patients with HSV-1, including ACVr HSV-1, shedding showed a significantly higher mortality rate. Relapsed malignancies were a significant risk factor for the emergence of ACVr HSV-1. Acyclovir resistance was attributable to viral thymidine kinase and DNA polymerase mutations in 6 and 5 patients, respectively.

Conclusions

Herpes simplex virus type 1, including ACVr HSV-1, shedding was associated with poorer outcome in HSCT patients, even if HSV disease did not always occur. Patients with relapsed malignancies were at especially high risk for the emergence of ACVr HSV-1.

Seroprevalence and correlates of herpes simplex virus type 2 infection among young adults in Arkhangelsk, Northwest Russia: a population-based cross-sectional study

Background

Herpes simplex virus type 2 (HSV-2) infection is the most common cause of genital ulcer disease (GUD) worldwide. Mother to child transmission causes high morbidity and mortality among infants. Russia is on the brink of a generalized HIV-epidemic, but Arkhangelsk is still a low-prevalence area. HSV-2 infection is associated with a three-fold increased risk of HIV-infection. The evidence on the seroprevalence of HSV-2 in Russia is limited. The aim of this study was to assess HSV-2 seroprevalence and correlates among young adults in the city of Arkhangelsk.

Methods

1243 adults aged 18-39 years participated in a cross-sectional population-based study, recruited by a public opinion agency applying a quota sampling method to achieve a data set with similar age- and sex-distribution as the population in Arkhangelsk. All participants completed a standardized, self-administrated questionnaire and were tested for HSV-2. Associations between HSV-2 seropositivity and selected sociodemographic and behavioral factors, and self-reported history of sexually transmitted infections (STIs) were studied by multivariable logistic regression.

Results

HSV-2 seroprevalence was 18.8 %: 12.2 % (95 % confidence interval, CI 9.7-15.2) among men and 24.0 % (95 % CI 20.1-27.3) among women. Among men, HSV-2 positivity was associated with being divorced/widowed (OR = 2.85, 95 % CI 1.06-7.70), cohabitation (OR = 2.45, 95 % CI 1.07-5.62), and a history of STIs (OR = 2.11, 95 % CI 1.14-3.91). In women, HSV-2 positivity was associated with high income (OR = 3.11, 95 % CI 1.45-6.71) and having a lifetime number of sexual partners between 2 and 5 (OR = 2.72, 95 % CI 1.14-6.51), whereas sexual debut at age 18 years or older was inversely associated with the outcome (OR = 0.47, 95 % CI 0.31-0.72). In both sexes, increasing age was the strongest correlate of HSV-2 seropositivity in multivariable analyses.

Conclusion

The HSV-2 seroprevalence was twice as high in women than in men and increased with age in both sexes, and similar to that reported from high-prevalence countries in Europe and the USA. The high prevalence of HSV-2 among women in childbearing age reveals the potential for HSV-2 transmission from mothers to infants and increased risk of acquisition HIV-infection; it also contributes to the burden GUD among both sexes. This emphasizes the public health implications of the HSV-2 epidemic in an urban population in North-West Russia.

Time-Series Analysis Comparing the Prevalence of Antibodies against Nine Viral Species Found in Umbilical Cord Blood in Japan

In this study, we investigated the prevalence of antibodies against 9 viral species found in umbilical cord blood from 561 neonates in 2013. Serum IgG antibodies against the following viruses were measured: herpes simplex virus (HSV), varicella-zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus 6 (HHV-6), measles virus (MV), rubella virus (RV), mumps virus (MuV), and human parvovirus B19 (HPV B19). A survey questionnaire regarding past medical history and maternal immunization status for the vaccine-preventable diseases of varicella, measles, rubella, and mumps was simultaneously administered. The results were compared with previous data collected in 2001-2002 from 378 umbilical cord blood samples. Viral seroprevalence data were: HSV, 54%; VZV, 96%; EBV, 96%; CMV, 67%; HHV-6, 100%; MV, 95%; RV, 94%; MuV, 64%; and HPV B19, 55%. The seroprevalence of CMV, MV, and MuV were significantly lower in 2013 than in 2001-2002 (CMV, 76%; MV, 98%; MuV, 93%). Compared with the 2001-2002 data, the mean IgG antibody values of the 4 vaccine-preventable diseases were significantly lower, and vaccination coverage for those diseases among mothers was significantly higher. Thus, attention should be paid to antibody levels in women of childbearing age in the future.

Seroprevalence of Herpes Simplex Virus Type 1 and 2 in Taiwan and Risk Factor Analysis, 2007

Background

Herpes simplex virus type 1 (HSV-1) and 2 (HSV-2) are common human pathogens and might cause severe illness. Following primary infection, the viruses establish lifelong latent infection and are transmitted by close contact, both sexual and nonsexual. However, the information about the seroprevalence of HSV-1 and HSV-2 across all age groups is limited.

Methods

Residual sera collected during the nationwide serosurvey in 2007 in Taiwan were selected for the study. The enzyme-linked immunosorbent assay was used to detect anti-HSV-1 and anti-HSV-2 type-specific glycoprotein IgG. Demographics and personal health data were used for risk analysis.

Results

A total of 1411 and 1072 serum samples were included for anti-HSV-1 and anti-HSV-2 seroprevalence analysis, respectively. The weighted overall seroprevalence was 63.2% for HSV-1, and 7.7% for HSV-2, respectively. The HSV-1 seropositive rate was 19.2% for those less than 5 years old, increased to 46.4% for those aged 5–13 years, 60.9% for those aged 14–29 years, and reached as much as 95.0% for those aged over 30 years. In contrast, the HSV-2 seropositve rate was 1.6% for those less than 30 years old, rose to 10.1% for those age 30–39 years, and was up to 31.2% for those aged over 60 years. A significantly higher HSV-2 seropositive rate was noted in females than males aged over 40 years (26.3% v.s. 16.8%), and the overall HSV-2 seropositive rate was almost twice higher in females than males. Smoking history, drinking habit, and educational level were associated with the HSV-1 seropositivity. Female gender and rural residence were independent factors for the HSV-2 seropositivity.

Conclusions

An obvious increase of primary HSV-1 infection occurred in late adolescents and young adults, joined by the rise of HSV-2 infection in middle-aged adults, especially females. The acquistion and transmission of HSV warrant further studies in the susceptible population.

Herpes simplex virus 2 infection: molecular association with HIV and novel microbicides to prevent disease

Infection with herpes simplex viruses is one of the most ancient diseases described to affect humans. Infection with these viruses produces vexing effects to the host, which frequently recur. Infection with herpes simplex viruses is lifelong, and currently there is no vaccine or drug to prevent or cure infection. Prevalence of herpes simplex virus 2 (HSV-2) infection varies significantly depending on the geographical region and nears 20% worldwide. Importantly, HSV-2 is the first cause of genital ulcers in the planet. HSV-2 affects approximately 500 million people around the globe and significantly increases the likelihood of acquiring the human immunodeficiency virus (HIV), as well as its shedding. Thus, controlling HSV-2 infection and spread is of public health concern. Here, we review the diseases produced by herpes simplex viruses, the factors that modulate HSV-2 infection, the relationship between HSV-2 and HIV and novel therapeutic and prophylactic microbicides/antivirals under development to prevent infection and pathological outcomes produced by this virus. We also review mutations associated with HSV-2 resistance to common antivirals.

Herpes simplex virus type 1 infection facilitates invasion of Staphylococcus aureus into the nasal mucosa and nasal polyp tissue

BACKGROUND

Staphylococcus aureus (S. aureus) plays an important role in the pathogenesis of severe chronic airway disease, such as nasal polyps. However the mechanisms underlying the initiation of damage and/or invasion of the nasal mucosa by S. aureus are not clearly understood. The aim of this study was to investigate the interaction between S. aureus and herpes simplex virus type 1 (HSV1) in the invasion of the nasal mucosa and nasal polyp tissue.

METHODOLOGY/PRINCIPAL FINDINGS

Inferior turbinate and nasal polyp samples were cultured and infected with either HSV1 alone, S. aureus alone or a combination of both. Both in turbinate mucosa and nasal polyp tissue, HSV1, with or without S. aureus incubation, led to focal infection of outer epithelial cells within 48 h, and loss or damage of the epithelium and invasion of HSV1 into the lamina propria within 72 h. After pre-infection with HSV1 for 24 h or 48 h, S. aureus was able to pass the basement membrane and invade the mucosa. Epithelial damage scores were significantly higher for HSV1 and S. aureus co-infected explants compared with control explants or S. aureus only-infected explants, and significantly correlated with HSV1-invasion scores. The epithelial damage scores of nasal polyp tissues were significantly higher than those of inferior turbinate tissues upon HSV1 infection. Consequently, invasion scores of HSV1 of nasal polyp tissues were significantly higher than those of inferior turbinate mucosa in the HSV1 and co-infection groups, and invasion scores of S. aureus of nasal polyp tissues were significantly higher than those of inferior turbinate tissues in the co-infection group.

CONCLUSIONS/SIGNIFICANCE

HSV1 may lead to a significant damage of the nasal epithelium and consequently may facilitate invasion of S. aureus into the nasal mucosa. Nasal polyp tissue is more susceptible to the invasion of HSV1 and epithelial damage by HSV1 compared with inferior turbinate mucosa.

Association of HSV reactivation and pro-inflammatory cytokine levels with the severity of stomatitis after BEAM chemotherapy and autologous SCT

BACKGROUND

Stomatitis, including oral mucositis and ulcerations induced by HSV-reactivation are major sources of morbidity after high-dose (HD) chemotherapy and subsequent autologous hematopoietic stem cell transplantation (SCT). While increased synthesis of pro-inflammatory cytokines, such as interleukin-1 (IL-1) and tumor necrosis factor alpha (TNF-α)-as well as reactivation of viral infections have frequently been observed in this setting, data on their association with the severity of mucositis is limited.

MATERIALS AND METHODS

Fifteen patients with Hodgkin's or non-Hodgkin's lymphoma receiving HD conditioning chemotherapy and autologous SCT were assessed with respect to oral pain and severity of stomatitis on day -6, 0, +5 to +7, +13 to +15, and +100. On the same dates, IL-1 and TNF-α were quantified in saliva and screening for a wide range of viral pathogens was carried out by cell culture and PCR and complemented by serological analyses. t Tests were used to assess potential associations between these variables.

RESULTS

All but one patient had a positive HSV IgG titer at baseline. Reactivation as confirmed by HSV PCR was observed in seven patients (50%). There was a significant association between the presence of HSV in saliva samples and severity of stomatitis (t test, p = 0.015). The highest concentration of TNF-α and IL-1 coincided with the maximum intensity of stomatitis, but the association was not significant.

CONCLUSION

We found a significant association between the presence of HSV in saliva samples and severity of stomatitis in patients receiving HD chemotherapy and subsequent autologous SCT. While acyclovir prophylaxis has become standard for patients undergoing allogeneic SCT, this issue has not been sufficiently explored for other chemotherapy regimens. Based on our findings, conduction of a well-powered controlled randomized trial may be warranted.

Immune response to intranasal and intraperitoneal immunization with Kaposi's sarcoma-associated herpesvirus in mice

A vaccine for Kaposi's sarcoma-associated herpesvirus (KSHV) is not currently available. To obtain the fundamental data in animals for vaccine development, KSHV particles were immunized to Balb/c mice through intraperitoneal and intranasal routes in the present study. Intranasal immunization with KSHV induced IgA to KSHV in not only serum, but also nasal wash fluid and saliva. A neutralization assay using recombinant KSHV that expressed green fluorescent protein revealed that nasal wash fluid and saliva from the KSHV-immunized mice neutralized KSHV infection to human embryonic kidney 293 cells in vitro in a dose-dependent manner to KSHV copies immunized. The serum and nasal wash fluid of KSHV-encoded K8.1 protein-immunized mice neutralized KSHV infection to 293 cells in vitro. These data suggest a possibility of mucosal vaccine for prophylaxis of KSHV infection.