Rotavirus vaccine and health-care utilization for rotavirus gastroenteritis in Tsu City, Japan.

Background: Rotavirus vaccines were introduced in Japan in November 2011. We evaluated the subsequent reduction of the health-care burden of rotavirus gastroenteritis.

Methods: We conducted active surveillance for rotavirus gastroenteritis among children under 5 years old before and after the vaccine introduction.

Laboratory Diagnosis of Breakthrough Varicella in Children.

Background: Breakthrough varicella (BV) develops in vaccinated persons as a result of infection by wild-type varicella-zoster virus more than 42 days after varicella vaccination. The clinical symptoms are atypical, and clinical diagnosis can be difficult. We investigated laboratory-based diagnostic methods that are relatively simple and highly precise to conduct accurate surveillance.

Cross-Neutralization between Human and African Bat Mumps Viruses.

Recently, a new paramyxovirus closely related to human mumps virus (MuV) was detected in bats. We generated recombinant MuVs carrying either or both of the fusion and hemagglutinin-neuraminidase bat virus glycoproteins. These viruses showed replication kinetics similar to human MuV in cultured cells and were neutralized efficiently by serum from healthy humans.

Serotypes, antimicrobial susceptibility, and molecular epidemiology of invasive and non-invasive Streptococcus pneumoniae isolates in paediatric patients after the introduction of 13-valent conjugate vaccine in a nationwide surveillance study conducted in Japan in 2012-2014.

Pneumococcal infection in children is a major public health problem worldwide, including in Japan. The pneumococcal conjugate vaccine 7 (PCV7) was licensed for use in Japan in 2010 followed by PCV13 in 2013. This report includes the results of a nationwide surveillance of invasive pneumococcal disease (IPD) and non-IPD in paediatric patients from January 2012 to December 2014.

Early disruption of neurovascular units and microcirculatory dysfunction in the spinal cord in spinal muscular atrophy type I.

Spinal muscular atrophy type I (SMA-I) is characterized by progressive muscle weakness with onset in early infancy, usually resulting in mortality before two years of age. However, the processes underlying the pathophysiological progression of the disease remain unclear. Prior to the onset of muscle weakness, a regression of local capillaries is observed along with motor neuron loss.

Effect of age on the incidence of aseptic meningitis following immunization with monovalent mumps vaccine.

Objective: The purpose of this study was to determine the risk of aseptic meningitis after mumps vaccination in younger children compared with older children.

Methods: This prospective cohort study included a total of 21,465 children under 18 years of age who had received the first dose of three of the Japanese mumps monovalent vaccine. We compared the cumulative incidence of aseptic meningitis for 30 days after vaccination among the following age groups: ≤ 1, 2, 3-4, and ≥ 5 years old.

Highly increased levels of IgE antibodies to vaccine components in children with influenza vaccine-associated anaphylaxis.

Background: Influenza vaccines produced in embryonated eggs might pose a risk to patients with egg allergy. However, patients experiencing influenza vaccine-associated anaphylaxis (IVA) do not always have egg allergy. In the 2011-2012 season, an unusually high incidence of IVA was reported in Japan.

Nationwide population-based surveillance of invasive pneumococcal disease in Japanese children: Effects of the seven-valent pneumococcal conjugate vaccine.

Background: In Japan, the seven-valent pneumococcal conjugate vaccine (PCV7) was introduced in 2010. PCV13 has replaced PCV7 since November 2013.

Methods: The effectiveness of PCV7 in protecting against invasive pneumococcal disease (IPD) in children aged <5 years was evaluated in a nationwide active population-based surveillance of IPD in 2008-2013 in 10 prefectures in Japan.

Outcomes and Prognostic Features of Patients With Influenza Requiring Hospitalization and Receiving Early Antiviral Therapy: A Prospective Multicenter Cohort Study.

Background: In Japan, the routine use of early antiviral therapy for patients with influenza is standard.

Methods: This multicenter prospective cohort evaluation of hospitalized patients with laboratory-confirmed influenza identified prognostic factors among the patients receiving antiviral therapy.

Results: Of 1,345 patients with influenza (766 pediatric, 579 adult), excluding those aged < 1 year (who are not approved for antiviral therapy), 97.

Seasonal split influenza vaccine induced IgE sensitization against influenza vaccine.

Although anaphylaxis is an extremely rare vaccine-associated adverse event, it occurred in young children following administration of the 2011/12 seasonal split influenza vaccine, which contained 2-phenoxyethanol as the preservative. These children had high levels of IgE antibodies against influenza vaccine components. We herein investigated why these children were sensitized.

Reactogenicity and immunogenicity of measles-rubella combined vaccine in school-entry-aged subjects with naturally acquired measles immunity.

Background: The reintroduction of measles-rubella combined (MR) vaccination to Japan raised concerns about adverse events as well as immunogenicity related to booster immunization in subjects with naturally acquired immunity to measles or rubella.

Methods: The time course of reactogenicity and antibody responses in recipients with pre-existing immunity to measles through natural infection was observed. Eighteen children aged 80-104 months received MR booster vaccination; 16 of them had had previous rubella vaccination.

Characteristics of group B Streptococcus isolated from infants with invasive infections: a population-based study in Japan.

Group B Streptococcus (GBS) is one of the leading causes of neonatal bacterial infections. Population-based surveillance of GBS-related invasive diseases among newborns and infants from 10 prefectures in Japan was performed between 2007 and 2012. The characteristics of cases and isolated GBS are described in this study.

Humoral immune response to influenza A(H1N1)pdm2009 in patients with natural infection and in vaccine recipients in the 2009 pandemic.

The 2009 pandemic H1N1 mainly affected adolescents and children, and most of the elderly in Japan escaped clinical illness. To clarify the role of humoral immunity in the infection, the time kinetics of hemagglutination inhibition (HI), neutralization (NT), and IgG subclass antibody response directed against influenza A(H1N1)pdm2009 were analyzed in three consecutive specimens obtained from 51 young adults and children (group 1) who contracted pandemic influenza and from 74 pediatric clinic employees (group 2) inoculated with pandemic monovalent vaccine. In group 1 patients, 6 and 30 patients had lower HI and NT antibody in the acute phase respectively.

Phylogenetic analysis and seroprevalence of influenza C virus in Mie Prefecture, Japan in 2012.

Reverse transcription polymerase chain reaction (RT-PCR) and real-time RT-PCR were used to detect 14 (6.6%) influenza C virus (InfC) among 213 clinical samples collected from children with respiratory symptoms in Mie Prefecture, Japan, between January 2012 and December 2012. Virus isolation using Madin-Darby canine kidney cells and/or embryonated chicken eggs was also successful for 3 of the 14 PCR-positive samples.

Hyporesponsiveness to the infecting serotype after vaccination of children with seven-valent pneumococcal conjugate vaccine following invasive pneumococcal disease.

Antibody responses to the infecting serotype in children who are vaccinated with pneumococcal conjugate vaccine (PCV) after having invasive pneumococcal diseases (IPD) have not been fully investigated. Of 56 children diagnosed with IPD between October 2009 and April 2013 in whom the infecting serotype was confirmed, 17 who were vaccinated with PCV7 following IPD were tested to determine the geometric mean concentration of serotype-specific immunoglobulin G (IgG) and the geometric mean titers of opsonization indices (OIs) using paired sera obtained at the onset of IPD and after PCV doses following the resolution of IPD. The geometric mean concentrations of serotype-specific IgG for all PCV7 serotypes other than serotype 6B were significantly increased after the last PCV7 dose compared with those at the time of IPD onset (P<0.

A new strategy for healthcare-associated pneumonia: a 2-year prospective multicenter cohort study using risk factors for multidrug-resistant pathogens to select initial empiric therapy.

Background: Optimal empiric therapy for hospitalized patients with healthcare-associated pneumonia (HCAP) is uncertain.

Methods: We prospectively applied a therapeutic algorithm, based on the presence of risk factors for multidrug-resistant (MDR) pathogens in a multicenter cohort study of 445 pneumonia patients, including both community-acquired pneumonia (CAP; n = 124) and HCAP (n = 321).

Results: MDR pathogens were more common (15.

[A study on the HA amount of HA influenza vaccination on efficacy and safety in infants].

We examined the efficacy and safety of inactivated influenza vaccine when the amount of HA influenza vaccination in children was increased to the dose recommended by the WHO. The purpose of this study was to obtain basic evidence to review the vaccination dose in Japanese children. HA influenza vaccine produced by the Research Foundation for Microbial Diseases of Osaka University (Biken) licenced in Japan was administered through vaccination at the international dose, and split HA influenza vaccine produced by Sanofi Pasteur corp.

Low opsonic activity to the infecting serotype in pediatric patients with invasive pneumococcal disease.

Serotype-specific protective immunity in pediatric patients with invasive pneumococcal disease (IPD) has not been fully investigated. To determine the protective immunity to the infecting serotype, the serotype-specific immunoglobulin G (IgG) levels and opsonization indices (OIs) were examined in 24 Japanese pediatric patients whose serum was collected within one month of an IPD episode between May 2008 and June 2011. The median age (range) of IPD patients was 17 (10-108) months and 63% were boys.

Alum-adjuvanted H5N1 whole virion inactivated vaccine (WIV) induced IgG1 and IgG4 antibody responses in young children.

IgG subclass antibody responses are not fully understood. Alum-adjuvanted H5N1whole virion inactivated vaccine (WIV), a genetically reassortant vaccine seed strain originating from H5N1/A/Vietnam/1194/2004 and PR-8, induced significantly stronger antibody responses in neutralizing antibodies in children. In this report, IgG subclass antibody responses were investigated, and most serum samples were positive for IgG1 antibody before immunization.