Evaluation of immunogenicity of mumps vaccine strains in cotton rat (Sigmodon hispidus) model.

Objectives: RIT 4385 (RIT) is cloned from the Jeryl Lynn mumps vaccine strain and is widely used in measles, mumps, and rubella combined vaccine (MMR) in many countries. Immunogenicity of RIT was investigated in cotton rats in comparison with domestic mumps vaccine (Hoshino strain) used in Japan.

Methods: Systemic distribution of mumps virus (MuV) genome was investigated in kidney, salivary glands, pancreas, testis/ovary, and brain tissues obtained at 1, 2, and 3 weeks after inoculation.

Immunogenicity, safety, and tolerability of a β-glucan-CpG-adjuvanted respiratory syncytial virus vaccine in Japanese healthy participants aged 60 to 80 years: A phase 2, randomized, double-blind, dose-finding study.

VN-0200 is an investigational β-glucan-CpG-adjuvanted respiratory syncytial virus (RSV) vaccine (antigen: VAGA-9001a [RSV F glycoprotein], adjuvant: MABH-9002b). This multicenter, randomized, double-blind, dose-finding phase 2 study explored the optimal VN-0200 dose and confirmed its humoral and cellular immunity and safety. In total, 342 healthy Japanese participants aged 60 to 80 years were randomized to one of 10 vaccination groups, each receiving a different combination of VAGA-9001a and MABH-9002a.

Non-inferiority and vaccine titer-confirmation studies of MMR vaccine (JVC-001; measles AIK-C, mumps RIT4385, and rubella Takahashi strains) in healthy 1-year-old Japanese children.

Objectives: JVC-001 is a new live attenuated measles-mumps-rubella vaccine (measles AIK-C, mumps RIT4385, and rubella Takahashi strains). Two phase 3 studies were conducted, one to verify the non-inferior immunogenicity of JVC-001 versus the approved mumps and measles-rubella vaccines (J301 study) and another to compare the immunogenicity and safety of different titers (J302 study).

Methods: Both studies were multicenter, randomized, observer-blinded, phase 3 studies.

Assessment of mumps virus-specific antibodies: Comparison of three different enzyme immunoassays and neutralization test.

Introduction: We evaluated the application of a newly improved enzyme immunoassay (EIA) kit, Mumps IgG Seiken®, by comparing antibody responses to different EIA kits, and neutralization tests (NTs), using clinical samples.

Methods: Serum samples were collected before and 4-6 weeks after vaccination from 128 children who had no history of mumps or mumps vaccination. Using three different EIA kits, Mumps IgG Seiken®, a commercial kit from Enzygnost®, and an in-house kit, mumps-specific IgG antibodies were measured.

Live-attenuated vaccine failure after liver transplantation: A 20-year cohort study.

Background: A recent conditional recommendation suggests considering live-attenuated vaccines for solid organ transplant recipients, yet the conditions of their safe and effective administration remain unclear.

Methods: This prospective study was conducted at Keio University Hospital from 2002 to August 2023. We gave a live-attenuated vaccine to liver transplant (LT) recipients fulfilling criteria for live-attenuated vaccines, including criteria for humoral and cell-mediated immunity.

Assessing clinical benefits of live-attenuated vaccination in post-liver transplant patients: Analysis of breakthrough infections and natural boosters.

Recently, live-attenuated measles, rubella, varicella, and mumps vaccines have been administered to carefully selected post-liver transplant patients. Although attention has been focused on post-vaccination antibody titers and adverse events, the real-life clinical benefits remain unclear. A comprehensive analysis of breakthrough infections and natural boosters (asymptomatic cases with significant elevation in virus antibody titers) following immunization post-liver transplantation was conducted from 2002-2023, exploring the timing, frequency, correlation with domestic outbreaks, and degree of antibody elevation.

The efficacy and safety of a quadrivalent live attenuated influenza nasal vaccine in Japanese children: A phase 3, randomized, placebo-controlled study.

Background: Vaccination is the primary method of preventing influenza infection and complications in young children. We evaluated the efficacy and safety of a single dose of MEDI3250 (intranasal, quadrivalent, live attenuated influenza vaccine) in healthy Japanese children during the 2016/17 influenza season.

Methods: In this multicenter, randomized, double-blind, phase 3 study (jRCT2080223345), participants aged 2-18 years received MEDI3250 or placebo (2:1), stratified by age (2-6 years, 7-18 years).

Phase III, open-label, single-arm study of a new MMR vaccine (JVC-001); measles AIK-C, mumps RIT 4385, rubella Takahashi, as a second vaccine dose in healthy Japanese children aged 5-6 years.

Purpose: This Phase III, multicenter, open-label, single-arm study evaluated the safety and immunogenicity of the measles-mumps-rubella (MMR) combined vaccine, JVC-001, as a second MMR vaccination.

Methods: Healthy Japanese children aged 5-6 years received a single dose of JVC-001 following a first measles, mumps, and rubella vaccination (measles-rubella bivalent and mumps monovalent vaccine [Hoshino or Torii strain] or JVC-001) or the MMR vaccine received between ages 1 to <4 years. Immunogenicity was evaluated using antibody titers before and after vaccination (Day 1/Day 43).

Cellular and humoral immune responses to COVID-19 booster vaccination in Japanese dialysis patients.

Background: Dialysis patients are susceptible to developing severe coronavirus disease 2019 (COVID-19) due to hypoimmunity. Antibody titers against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) after the primary vaccinations are lower in hemodialysis (HD) patients than in healthy individuals. This study aimed to evaluate the effect of a SARS-CoV-2 booster vaccination in HD and peritoneal dialysis (PD) patients based on antibody titers and cellular and humoral immunity.

Cytokine and Chemokine Production in Mice Inoculated with NVX-CoV2373 (Nuvaxovid) in Comparison with Omicron BA.4/5 Bivalent BNT162b2 (Comirnaty).

A recombinant SARS-CoV-2 spike protein vaccine (NVX-CoV2373) has been licensed and has a lesser incidence of adverse events. To know the immunological mechanisms of adverse events, the production of cytokines and chemokines was investigated in mice inoculated with NVX-CoV2373. Serum IL-6 was detected on Day 1 of the first and second doses and the IFN-γ, IL-4, IL-10, TNF-α, and IL-6 levels increased on Day 1 of the second dose at the inoculation site.

Different immunological responses following immunization with two mRNA vaccines.

Introduction: Immunological responses were investigated following immunization with two mRNA vaccines: BNT162b2 and mRNA-1273.

Methods: Neutralizing antibody (NAb) was assayed before, 2-4 weeks after, and 3 and 6 months after the primary immunization, and the same time-points after booster dose with 6- or 8-months interval. Whole-blood culture was stimulated with spike antigen, and cytokine production was assayed.

DS-5670a, a novel mRNA-encapsulated lipid nanoparticle vaccine against severe acute respiratory syndrome coronavirus 2: Results from a phase 2 clinical study.

Background: DS-5670a is a vaccine candidate for coronavirus disease 2019 (COVID-19) harnessing a novel modality composed of messenger ribonucleic acid (mRNA) encoding the receptor-binding domain (RBD) from the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) encapsulated in lipid nanoparticles. Here, we report the safety, immunogenicity, and pharmacokinetic profile of DS-5670a from a phase 2 clinical trial in healthy adults who were immunologically naïve to SARS-CoV-2.

Methods: The study consisted of an open-label, uncontrolled, dose-escalation part and a double-blind, randomized, uncontrolled, 2-arm, parallel-group part.

A Marked Eosinophilic Infiltration in Mucosa Could Be a Better Predictive Factor for Intractable Non-Esophageal Eosinophilic Gastrointestinal Disorders.

Introduction: Non-esophageal eosinophilic gastrointestinal disorders (non-EoE EGIDs) are rare, but their prevalence has recently increased. Although it has been reported that one-half of patients with non-EoE EGIDs have intractable clinical courses, their clinical features are not fully understood.

Methods: This is a multicenter retrospective study in which 10 institutions in Japan participated.

Comparison of cytokine production in mice inoculated with messenger RNA vaccines BNT162b2 and mRNA-1273.

Two messenger RNA (mRNA) vaccines of BNT162b2 and mRNA-1273 were licensed. The most common adverse event is regional pain at the injection site in 80%. As systemic reactions, fatigue and headache were noted in 40%-60% and febrile illness in 10%-40% of the recipients.

Pertussis, diphtheria, and tetanus antibodies seroprevalence in pregnant women and neonates, as a preliminary data for introduction of preconception or prenatal DTaP vaccination among Japanese society.

An increasing number of countries have been introducing acellular pertussis vaccination during pregnancy for the prevention of neonatal pertussis. In response to the fact that infantile pertussis cases of 0-5 months age groups remained unchanged despite the universal vaccination program, prenatal pertussis vaccination has been a rising issue in Japan. Hence, we investigated the seroprevalence of pertussis, diphtheria, and tetanus antibodies in Japanese pregnant women and neonates, and evaluated the necessity of diphtheria-tetanus-acellular pertussis (DTaP) vaccination during the preconception or prenatal period.

Chemokine/Interleukin Imbalance Aggravates the Pathology of Respiratory Syncytial Virus Infection.

(1) Background: Almost 100% of children are initially infected by respiratory syncytial virus (RSV) by the age of 2 years, with 30% to 40% of children developing lower respiratory tract infections, of which 1% to 3% become severe. The severity of RSV-induced disease correlates with the influx of leukocytes, which leads to damage of the airways. We hence performed an immunological study based on the assumption that a chemokine/interleukin imbalance affects respiratory disorders caused by bronchiolitis and severe pneumonia.

Increased Production of Inflammatory Cytokines after Inoculation with Recombinant Zoster Vaccine in Mice.

Increasing numbers of patients with zoster were reported recently, and recombinant zoster vaccine (Shingrix) was licensed using the AS01 adjuvant system. Although it induces highly effective protection, a high incidence of local adverse events (regional pain, erythema, and swelling) has been reported with systemic reactions of fever, fatigue, and headache. To investigate the mechanism of local adverse events, cytokine profiles were investigated in mice injected with 0.

Appropriate Needle Length Determined by Ultrasonic Echography for Intramuscular Injection in Japanese Elderly over 50 Years.

Adjuvanted vaccines are administered through intramuscular injection. To perform appropriate injection using an appropriate needle in different age groups or different daily living activities, we investigated the depth from the skin surface to muscle fascia and bone in the deltoid muscle area in 156 elderly aged ≥ 50 years by ultrasonic echography. Subjects consisted of 50 healthy elderly aged 50−64 years, 50 subjects aged 65−74 years, and 56 subjects aged ≥ 75 years (20 outpatients, 18 who needed nursing care, and 18 bedridden in a nursing home).

Chimeric Measles Virus (MV/RSV), Having Ectodomains of Respiratory Syncytial Virus (RSV) F and G Proteins Instead of Measles Envelope Proteins, Induced Protective Antibodies against RSV.

In our previous study, fusion (F) or glyco (G) protein coding sequence of respiratory syncytial virus (RSV) was inserted at the P/M junction of the measles AIK-C vector (MVAIK), and the recombinant measles virus induced protective immune responses. In the present study, the ectodomains of measles fusion (F) and hemagglutinin (HA) proteins were replaced with those of RSV F and G proteins, and a chimeric MV/RSV vaccine was developed. It expressed F and G proteins of RSV and induced cytopathic effect (CPE) in epithelial cell lines (Vero, A549, and HEp-2 cells), but not in lymphoid cell lines (B95a, Jurkat, and U937 cells).

Changes in epidemiological characteristics and sero-prevalence against the varicella zoster virus in school-age children after the introduction of a national immunization program in Japan.

A national immunization program using two doses of live attenuated varicella vaccine was introduced for children aged one to two years in Japan in October 2014. Varicella cases declined after 2014, and immunological status against varicella among vaccinated children changed in post-vaccination era. A retrospective observational study of anti-varicella antibody seroprevalence, varicella vaccination status, and history of varicella among 528 students in the first grade of elementary school was conducted.

Immunogenicity and safety of a DTaP-IPV/Hib pentavalent vaccine given as primary and booster vaccinations in healthy infants and toddlers in Japan.

Background: Globally, the use of single DTaP-IPV/Hib vaccines that combine DTaP-IPV and Hib is widespread, but in Japan vaccination is usually concomitant at separate sites. The immunogenicity and safety of a primary vaccination series and booster of a combined pentavalent DTaP-IPV/Hib vaccine were evaluated and compared to separate administration of DTaP-IPV and Hib in Japanese infants.

Methods: Healthy Japanese infants were administered DTaP-IPV/Hib (Group A: N = 207) or DTaP-IPV + Hib (Group B: N = 207) by the subcutaneous (SC) or DTaP-IPV/Hib by the intramuscular (IM) route (Group C: N = 10).