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. OBJECTIVE: We sought to identify the cause of the increase in anaphylactic events in 2011-2012 in Japan. METHODS: We collected blood specimens from patients with IVA from all areas of Japan. We analyzed 19 patients with confirmed IVA and 25 age-matched control subjects, including 10 with egg allergy who had no adverse events after corresponding vaccination. ELISA was used to measure specific IgE levels to the trivalent vaccines of several manufacturers and hemagglutinin proteins derived from both egg and cell cultures. Antigen-induced basophil activation was evaluated by measuring CD203c expression by means of flow cytometry. Vaccine excipients were also examined for effects on CD203c expression. RESULTS: None of the patients with IVA had severe egg allergy. Levels of specific IgE antibodies to influenza vaccine antigens, whole-vaccine products from different manufacturers, and hemagglutinin proteins (A H1, H3, and B) derived from both egg and cell cultures were significantly increased in patients with IVA compared with those in control subjects. Influenza vaccine-induced CD203c expression in basophils was also highly enhanced in patients with IVA but not in control subjects. Because IVA was most frequent in patients who received 2-phenoxyethanol (2-PE)-containing vaccine, the effect of this preservative on basophil activation was examined, and the activation was slightly enhanced by 2-PE but not thimerosal. CONCLUSIONS: The 2011-2012 IVA spike in Japan was caused by specific IgE antibodies to influenza vaccine components. Excipients could not be implicated, except for a modest effect of 2-PE.

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.

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. RESULTS: There were virtually no clinical reactions related to booster vaccination, and a highly significant antibody response to rubella antigen, whereas the antibody rise to measles was statistically significant but poor. CONCLUSIONS: Vaccination of individuals already immune is not harmful. Booster immunization to rubella for Japanese children is vitally important.

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 (15.3% vs 0.8%, P < .001) in HCAP patients than in CAP patients, including Staphylococcus aureus (11.5% vs 0.8%, P < .001); methicillin-resistant S. aureus (6.9% vs 0%, P = .003); Enterobacteriaceae (7.8% vs 2.4%, P = .037); and Pseudomonas aeruginosa (6.9% vs 0.8%, P = .01). Using the proposed algorithm, HCAP patients with ≥2 MDR risk factors, one of which was severity of illness (n = 170), vs HCAP patients with 0-1 risk factor (n = 151) had a significantly higher frequency of MDR pathogens (27.1% vs 2%, P < .001). In total, 93.1% of HCAP patients were treated according to the therapy algorithm, with only 53% receiving broad-spectrum empiric therapy, yet 92.9% received appropriate therapy for the identified pathogen. Thirty-day mortality was significantly higher for HCAP than for CAP (13.7% vs 5.6%, P = .017), but among HCAP patients with 0-1 MDR risk factor, mortality was lower than with ≥2 MDR risk factors (8.6% vs 18.2%, P = .012). In multivariate analysis, initial treatment failure, but not inappropriate empiric antibiotic therapy, was a mortality risk factor (odds ratio, 72.0). CONCLUSIONS: Basing empiric HCAP therapy on its severity and the presence of risk factors for MDR pathogens is a potentially useful approach that achieves good outcomes without excessive use of broad-spectrum antibiotic therapy. CLINICAL TRIALS REGISTRATION: Japan Medical Association Center for Clinical Trials, JMA-IIA00054.

[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. (Sanofi) was used as control. Children from 6 months to less than 13 years of age were registered, and vaccinated with doses of 0.25 mL or 0.5 mL. Clinical symptoms during the influenza season were monitored to investigate vaccine efficacy, and information on adverse reactions was collected to evaluate safety profile. Paired serum HI and NT antibody titers were measured at pre first dose and post second dose of vaccination. Both HI and NT antibody titers for H1N1 subtype were satisfactory elevated after administration of both vaccines. Elevation of the NT antibody titer for the H3N2 subtype was observed for both vaccines, but the H3N2 HI antibody titer for the Biken vaccine was not so high. For the subtype B virus, the NT titer had a better response than the HI titer for both vaccines. As only the H1N1 virus was prevalent in the area during the study period, we performed factor analysis concerning influenza contraction only for the H1N1 antibody titer. An HI titer of 1 : 40 or more at post-vaccination was a significant factor to lower the risk of influenza contraction. The relative risk for fever among children with an HI titer of 1 : 20 or less was significantly higher than those with an HI titer of 1 : 40 or more. Children with a higher HI titer had better prevention against fever, so that both vaccines were considered to be effective. As for the appearance of adverse reactions, both vaccines were considered to be safe. From the above-mentioned results, vaccination with the Japanese Biken vaccine at an international dose was thought to be an effective and safe procedure.

Elevated numbers of cells producing interleukin-5 and interleukin-10 in a boy with Kimura disease.

Kimura disease is a rare disorder of unknown etiology, characterized by the presence of benign subcutaneous granuloma, marked peripheral blood eosinophilia and elevation of the immunglobulin E (IgE) serum level. Here, we present a case of a 12-year-old boy with Kimura disease who had a history of repeated severe influenza virus A infection. Along with the characteristic histological findings of granuloma, including eosinophil infiltration, enzyme-linked immunospot assay showed elevated numbers of IL-5- and IL-10-producing cells in the peripheral blood. Immunohistochemical evaluation, however, did not detect IL-5 in the tissue. Possible cytokine dysregulation in Kimura disease was suggested, but the pathogenesis remains unclear.

Survey of Japanese infants younger than 3 months who were treated with oseltamivir for influenza: safety of oseltamivir treatment.

BACKGROUND: Young infants with influenza virus infection are frequently hospitalized, and are at risk of serious complications including death. With the emergence of pandemic influenza A/H1N1 2009, oseltamivir was approved for use in Europe and the USA, including use in infants aged < 3 months. However, few data are available regarding the safety of oseltamivir treatment for influenza in infants aged < 3 months. METHODS: The clinical data from Japanese infants aged < 3 months with laboratory-confirmed influenza virus infections, who were treated with oseltamivir between October 2009 and April 2011, were collected and analyzed. RESULTS: Forty-four infants were included in the study. The median age was 1 month (range 4 days to 2 months) and median body weight was 4.5 kg (range 2.6-7.6 kg). Thirty-eight infants (86%) had no underlying diseases. The most common presenting symptom was fever (42 infants, 95%). There were no cases of influenza-associated encephalopathy or myocarditis. The median time between the onset of influenza symptoms and initiation of oseltamivir treatment was 0 days (range 0-7 days), with treatment initiated within 1 day in 40 infants (91%). The oseltamivir dose was 1.5-2 mg/kg twice daily in 98% of infants. No serious adverse events were identified during treatment. All infants recovered completely. CONCLUSIONS: Treatment of influenza with oseltamivir 1.5-2 mg/kg twice daily may be safe in infants aged < 3 months.

An 8-year-old boy with hypereosinophilic syndrome.

Hypereosinophilic syndrome (HES) is a heterogeneous group of uncommon disorders characterized by the presence of marked peripheral blood eosinophilia and tissue eosinophilia, resulting in a wide variety of clinical manifestations. We present the case of an 8-year-old boy with HES. He complained of recurrent abdominal pain, general fatigue, and diarrhea. Laboratory data showed marked eosinophilia, elevated total IgE with positive specific IgE antibodies to common inhalant and food allergens, and elevated serum CCL17/TARC. A chest CT scan revealed central bronchiectasis, bronchial wall thickening, a mosaic attenuation pattern, and multiple small nodules in lung parenchyma; abdominal CT showed a thickened bladder wall. Gastrointestinal endoscopy revealed scarring in the gastric mucosa and mucosal erosion in the duodenum. Immunohistochemical examination demonstrated numerous eosinophil infiltrations with extensive extracellular eosinophil major basic protein deposition in the gastric mucosa. Only high-dose oral steroid was effective and cyclosporine appeared to have a steroid-sparing effect. HES is extraordinary rare in children and the long-term prognosis in pediatric HES is not well known. Comprehensive diagnostic procedures are vital for the early detection and management of complications in pediatric HES.

Amino Acid substitutions in matrix, fusion and hemagglutinin proteins of wild measles virus for adaptation to vero cells.

BACKGROUND: Wild-type measles virus (MV) is isolated in B95a but not in Vero cells. Through an adaptation process of wild-type MV to Vero cells, several amino acid substitutions were reported. METHODS: Six strains were adapted to Vero cells and membrane (M), fusion (F) and hemagglutinin (H) genes were sequenced. Cell fusion was assessed and recombinant MVs were constructed, having wild-type H or M gene with or without mutations. RESULTS: No F gene substitution was noted. Amino-acid substitutions at positions 481 from Asn to Tyr (N481Y) and 546 from Ser to Gly (S546G) were observed in the H protein. Glu at position 89 of the M protein was substituted for Gly (E89G) and two mutations were noted at positions 62 (S62R) and 83 (S83P) in M protein. Recombinant viruses with mutation(s) detected in Vero-adapted strains induced a cytopathic effect and grew well in Vero cells, but those with the wild type did not. Recombinant viruses with mutation(s) demonstrated lower viral growth in B95a cells. CONCLUSIONS: Substitutions of E89G, S62R and S83P of the M protein were newly observed through adaptation to Vero cells, besides the mutations described in previous reports, with varying adaptation for each strain.

Remarkable similarity in genome nucleotide sequences between the Schwarz FF-8 and AIK-C measles virus vaccine strains and apparent nucleotide differences in the phosphoprotein gene.

The Schwarz FF-8 (FF-8) and AIK-C measles virus vaccine strains are currently used for vaccination in Japan. Here, the complete genome nucleotide sequence of the FF-8 strain has been determined and its genome sequence found to be remarkably similar to that of the AIK-C strain. These two strains are differentiated only by two nucleotide differences in the phosphoprotein gene. Since the FF-8 strain does not possess the amino acid substitutions in the phospho- and fusion proteins which are responsible for the temperature-sensitivity and small syncytium formation phenotypes of the AIK-C strain, respectively, other unidentified common mechanisms likely attenuate both the FF-8 and AIK-C strains.

[The National Vaccine Injury Compensation Program in Japan].

Two vaccination systems have been employed in Japan, the routine vaccination and the voluntary vaccination. The National Vaccine Injury Compensation Program in Japan is no-fault system. Claims after the routine vaccination are demanded to the Ministry of Health, Labour and Welfare through local governments, and compensation is more expenses. Meanwhile, claims after the voluntary vaccination are demanded to the Pharmaceuticals and Medical Device Agency directly, and compensation is less compared with the routine vaccination.

Contribution of matrix, fusion, hemagglutinin, and large protein genes of the CAM-70 measles virus vaccine strain to efficient growth in chicken embryonic fibroblasts.

Attenuated live vaccines of measles virus (MV) have been developed from clinical isolates by serial propagation in heterologous cells, mainly chicken embryonic cells. The safety and effectiveness of these vaccines have been well established. However, the molecular mechanism of their attenuation remains a subject of investigation. The CAM-70 MV vaccine strain was developed from the Tanabe strain by serial propagation in chicken embryonic cells. In the present study, we assessed the contribution of each gene in the CAM-70 strain to efficient growth in chicken embryonic fibroblasts (CEF). We used a cloned MV IC323 based on the wild-type IC-B strain and generated a series of IC323s that possess one or more of the CAM-70 genes. Then, we examined the infection of CEF and CEF expressing human signaling lymphocyte activation molecule with the recombinant MVs. Our results demonstrated that MV needs to adapt to CEF at both the entry and postentry steps and that the CAM-70 matrix protein gene plays an important role in adaptation to CEF at the early stage of the virus replication cycle. The CAM-70 large protein gene was responsible for the efficient transcription and replication in CEF, and the CAM-70 hemagglutinin and fusion protein genes were responsible for efficient entry. Investigations focusing on these genes might elucidate unknown molecular mechanisms underlying the attenuation of MV.

Detection of measles virus RNA on SYBR green real-time reverse transcription-polymerase chain reaction.

BACKGROUND: As the coverage rate of the measles vaccine increases, not all patients present the typical symptoms of measles after exposure to the measles virus (MV). The virus loads in clinical specimens from patients with vaccine-modified non-typical measles are expected to be low compared with those of primary MV infection. A rapid and sensitive laboratory procedure is required for diagnosis of measles. METHODS: SYBR Green (TaKaRa) and TaqMan (ABI) real-time reverse transcription-polymerase chain reaction (RT-PCR) assays were developed to detect MV-RNA. For the real-time RT-PCR, primer sets were designed from a region of the MV H gene of the Edmonston strain (genotype A). A TaqMan probe specific for the H gene of genotype D MV was used. The minimum detectable level of MV-RNA in the SYBR Green and TaqMan real-time RT-PCR assays was evaluated using synthetic MV-RNA. The sensitivity of real-time RT-PCR was compared with that of nested RT-PCR and the virus isolation method using throat swabs and peripheral blood samples from patients with measles. RESULTS: The minimum detectable level of RNA was 10 and 10(2) copies for SYBR Green RT-PCR and TaqMan RT-PCR, respectively. Ten-10(6) copies of standard RNA were linearly detected on SYBR Green RT-PCR. The sensitivity of SYBR Green RT-PCR was equal to that of nested RT-PCR. MV-RNA was detected in virus isolation-negative throat swabs on SYBR Green RT-PCR. CONCLUSION: SYBR Green RT-PCR is a highly sensitive, rapid, and useful diagnostic procedure for the detection of MV.

[Evaluation of alum-adjuvanted whole virus influenza vaccine and future aspects of influenza A (H1N1) 2009 vaccine].

For preparedness of H5N1 pandemic, several types of influenza prototype vaccine have been developed in several countries. Alum-adjuvanted whole virus influenza vaccine, which has been developed in Japan, had excellent priming effect after two doses, and the third shot of the heterologous strain to the subjects primed two years previously elicited strong and broad cross immunity. Moreover, solicited local and general reactions were acceptable. However, influenza A (H1N1) 2009 virus, which had much different antigenicity from A Russia lineage, was detected in April 2009 and developed pandemic. According to clinical studies of (H1N1) 2009 monovalent vaccine in adults, split vaccine could induce appropriate secondary immune responses after one dose. These results suggested that adults had immune memory to (H1N1) 2009 virus, and that vaccination strategy to this virus was efficient by using seasonal influenza vaccination strategy. Additionally, since WHO speculates (H1N1) 2009 virus could be endemic in near future, the (H1N1) 2009 virus-derived strain is included in the 2010/11 seasonal influenza vaccine.

[Influenza vaccination: recommendations and remarks].

Several types of influenza vaccine have been developed in the world. Split vaccine has been used as seasonal influenza vaccine and 2009 pandemic monovalent vaccine in Japan. Seasonal influenza vaccine should be administered annually to the health-care personnels, the higher risk persons who had suffered from influenza, and household contacts and caregivers of higher risk persons. Since 2009 pregnant women could be administered with split vaccine in Japan. Since the split vaccine in Japan contains 1-10 ng/mL of ovalbumin, children with egg-allergy could be administered safely.

Modified adult measles in outbreaks in Japan, 2007-2008.

Different genotypes of C1, D3, D5, and H1 were isolated in outbreaks of 1984, 1987-1988, 1991-1993, and 2001, respectively, when the previous circulating genotype was replaced successively by a new genotype, through molecular studies of measles since 1984 in Japan. In March 2007, several patients with measles were observed in outpatient clinics, who were all young adolescents in high school and university students. The outbreak expanded subsequently throughout Japanese districts in May and is still ongoing in 2008. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) was used to detect the measles genome from 18 clinical samples obtained from patients suspected of modified measles infection with a very mild febrile illness. The measles genome was detected in nine patients by reverse transcription polymerase chain reaction (RT-PCR) and in 12 patients by RT-LAMP. Six measles strains were isolated in the 2007-2008 outbreak and identified as the D5 genotype (MVi/Bangkok.THA/93 type) different from the D5 sub-cluster (MVi/Palau.BLA/93 type) isolated in 1990-2005. Similar Bangkok type D5 strains were isolated in Phnom Penh in 2002 and in Taiwan in 2003, suggesting that the D5 strains might have been introduced via South East Asia, rather than resulting from the accumulation of mutations in the D5 strains of 1990-2005. One D9 strain was isolated from a sporadic case in Aichi in 2006. There was no difference in the antigenicity of the D9 and D5 strains in comparison with the vaccine strain. Infrastructure of systematic laboratory-based surveillance system should be established in order to confirm measles virus infection in Japan.

Sensitivity of rapid immunoassay for influenza A and B in the early phase of the disease.

BACKGROUND: Immunochromatography (IC) tests are often used for the rapid diagnosis of influenza. Once influenza is diagnosed, an anti-influenza drug can be administered. Physicians claim, however, that they are not sufficiently sensitive, especially in the early phase of the disease. The aim of the present study was therefore to analyze the sensitivity of the IC test from the standpoint of virology. METHODS: To evaluate the sensitivity of the IC test statistically, 736 nasopharyngeal specimens were subjected to the IC test and virus isolation (VI). The IC test (+) specimens were compared with VI (+) specimens in the early phase after fever onset. Amounts of the virus in IC(-)VI(+) specimens were compared with those in IC(+)VI(+) specimens on real-time reverse transcriptase-polymerase chain reaction. The isolated viruses from these specimens were subjected to the IC test at the same dose. The nucleotide sequences of NP genes were compared. RESULTS: The IC test was less sensitive for diagnosis in the early phase of the disease. Amounts of virus were significantly lower in IC(-)VI(+) specimens than in IC(+)VI(+) specimens. No variations were observed in the isolated viruses. CONCLUSIONS: The IC test is not sufficiently sensitive owing to the low amount of virus in the nasopharyngeal tract in the early phase of the disease. Influenza should be diagnosed on the basis of clinical symptoms within 1 day after the fever onset.

Quantitative detection of HCMV-DNA in saliva from infants and breast milk on real-time polymerase chain reaction.

BACKGROUND: The role of breast milk in viral transmission has not been fully studied. To determine the effect of breast milk on the establishment of primary human cytomegalovirus (HCMV) infection in term infants, HCMV-DNA was measured in breast milk and infant saliva. METHODS: The study population consisted of 48 healthy term infants and their mothers. The copy number of HCMV-DNA in the infants' saliva and mothers' milk was measured on quantitative real-time polymerase chain reaction (PCR). RESULTS: HCMV-DNA was detected in both saliva and breast milk from 21 infant-mother pairs, in milk only from four pairs, in saliva only from 12 pairs, and in neither from 11 pairs. HCMV-DNA was first detected in the saliva of 10 infants at age 4 months, seven infants at 7 months, 13 infants at 10 months, and three infants at 12 months. The viral loads peaked 4-10 months after birth, and thereafter decreased or became negative. The peak copy number and rate of HCMV-DNA detection in saliva were significantly related to peak copy number and rate of detection in the corresponding breast milk. CONCLUSION: Thus, HCMV passed through breast milk 1-7 months after delivery affects the persistence and level of HCMV-DNA in infant saliva and is the most important route of primary infection.