Infant vaccinations and risk of childhood acute lymphoblastic leukaemia in the USA.
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Previous studies have suggested that infant vaccinations may reduce the risk of subsequent childhood leukaemia. Vaccination histories were compared in 439 children (ages 0-14) diagnosed with acute lymphoblastic leukaemia (ALL) in nine Midwestern and Mid-Atlantic states (USA) between 1 January 1989 and 30 June 1993 and 439 controls selected by random-digit dialing and individually matched to cases on age, race and telephone exchange. Among matched pairs, similar proportions of cases and controls had received at least one dose of oral poliovirus (98%), diphtheria-tetanus-pertussis (97%), and measles-mumps-rubella (90%) vaccines. Only 47% of cases and 53% of controls had received any Haemophilus influenzae type b (Hib) vaccine (relative risk (RR) = 0.73; 95% confidence interval (CI) 0.50-1.06). Although similar proportions of cases (12%) and controls (11%) received the polysaccharide Hib vaccine (RR = 1.13; 95% CI 0.64-1.98), more controls (41%) than cases (35%) received the conjugate Hib vaccine (RR = 0.57; 95% CI 0.36-0.89). Although we found no relationship between most infant vaccinations and subsequent risk of childhood ALL, our findings suggest that infants receiving the conjugate Hib vaccine may be at reduced risk of subsequent childhood acute lymphoblastic leukemia. Further studies are needed to confirm this association and, if confirmed, to elucidate the underlying mechanism. (+info)
Opportunistic immunisation in hospital.
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AIM: To assess the potential for administering catch up and scheduled immunisations during hospital admission. METHODS: Immunisation status according to the child's principal carer was checked against official records for 1000 consecutively admitted preschool age children. Junior doctors were instructed to offer appropriate vaccination before discharge, and consultants were asked to reinforce this proactive policy on ward rounds. RESULTS: Excluding those children who were not fully immunised against pertussis through parental choice, 142 children (14.2%) had missed an age appropriate immunisation and 41 were due a scheduled immunisation. None had a valid contraindication. Only 43 children were offered vaccination on the ward but uptake was 65% in this group. CONCLUSIONS: Admission to hospital provides opportunities for catch up and routine immunisations and can contribute to the health care of an often disadvantaged group of children. These opportunities are frequently missed. Junior doctors must be encouraged to see opportunistic immunisation as an important part of their routine work. (+info)
Kawasaki disease: a maturational defect in immune responsiveness.
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Kawasaki disease (KD), an acute febrile disease in children of unknown etiology, is characterized by a vasculitis that may result in coronary artery aneurysms (CAAs). In new patients with KD, a selective and prolonged T cell unresponsiveness to activation via the T cell antigen receptor CD3 was observed, whereas proliferation to other stimuli was intact. This "split T cell anergy" delineated KD from other pediatric infections and autoimmune diseases and correlated with CAA formation (P<.001). A transient immune dysfunction was also suggested by an incomplete responsiveness to measles-mumps-rubella (MMR) vaccination in patients with KD versus controls (P<.0001; odds ratio, 15.6; 95% confidence interval, 4.8-51.1), which was overcome by revaccination(s). The reduced responsiveness to MMR in patients with KD suggests a subtle and predetermining immune dysfunction. An inherent immaturity to clear certain antigens may be an important cause that precipitates KD and the immune dysregulation during acute disease. (+info)
Infection with wild-type mumps virus in army recruits temporally associated with MMR vaccine.
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Four cases of mumps were reported among 180 army recruits who had received MMR vaccine 16 days earlier. Mumps serology, salivary mumps IgM and PCR tests for the SH gene were performed on the 4 cases and on 5 control recruits who remained well. PCR products were sequenced and the sequences compared to those of wild type and vaccine strains of mumps. Further salivary mumps IgM tests were performed on the remaining 171 recruits. Mumps infection was confirmed in the 4 cases but not in the 5 controls. The controls had serological evidence of prior immunity. The SH gene sequence found in the 4 cases was wild type. Saliva tests identified 2 additional recruits with mumps IgM, one of whom had presented with suspected mumps 2 days before the MMR vaccine was given. Thus 6 (5 symptomatic and 1 asymptomatic) cases of mumps in army recruits recently receiving MMR vaccine were not due to the vaccine but to coincidental infection with wild-type mumps virus. The probable index case was revealed by salivary mumps IgM tests. This study highlights the importance of appropriate investigation of illness associated with MMR vaccination. (+info)
Increase in congenital rubella occurrence after immunisation in Greece: retrospective survey and systematic review.
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OBJECTIVE: To describe the events leading to the epidemic of congenital rubella syndrome in Greece in 1993 after a major rubella epidemic. DESIGN: Retrospective survey and systematic review. SETTING: Greece (population 10 million), 1950-95. SUBJECTS: Children, adolescents, and women of childbearing age. RESULTS: Around 1975 in Greece the measles, mumps, and rubella vaccine started being given to boys and girls aged 1 year without policies to attain high vaccination coverage and to protect adolescents and young women. During the 1980s, vaccination coverage for rubella remained consistently below 50%, and the proportion of pregnant women susceptible to rubella gradually increased. In 1993 the incidence of rubella in young adults was higher than in any previous epidemic year. The epidemic of congenital rubella that followed, with 25 serologically confirmed cases (24.6 per 100 000 live births), was probably the largest such epidemic in Greece after 1950. CONCLUSIONS: With low vaccination coverage, the immunisation of boys and girls aged 1 year against rubella carries the theoretical risk of increasing the occurrence of congenital rubella. This phenomenon, which has not been previously reported, occurred in Greece. (+info)
Measles inclusion-body encephalitis caused by the vaccine strain of measles virus.
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We report a case of measles inclusion-body encephalitis (MIBE) occurring in an apparently healthy 21-month-old boy 8.5 months after measles-mumps-rubella vaccination. He had no prior evidence of immune deficiency and no history of measles exposure or clinical disease. During hospitalization, a primary immunodeficiency characterized by a profoundly depressed CD8 cell count and dysgammaglobulinemia was demonstrated. A brain biopsy revealed histopathologic features consistent with MIBE, and measles antigens were detected by immunohistochemical staining. Electron microscopy revealed inclusions characteristic of paramyxovirus nucleocapsids within neurons, oligodendroglia, and astrocytes. The presence of measles virus in the brain tissue was confirmed by reverse transcription polymerase chain reaction. The nucleotide sequence in the nucleoprotein and fusion gene regions was identical to that of the Moraten and Schwarz vaccine strains; the fusion gene differed from known genotype A wild-type viruses. (+info)
Sex differences in antibody- and cell-mediated immune response to rubella re-immunisation.
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Antibody (AMI) and cell-mediated (CMI) immunity to rubella virus (RV) were evaluated in healthy adolescent males (n = 11) and females (n = 28) undergoing routine reimmunisation with RA27/3 strain RV as a component of measles-mumps-rubella (MMR) vaccine. Blood samples were collected just before and at 2, 4 and 10 weeks after MMR. While there were no sex differences before MMR and at week 10 after vaccination, levels of specific IgG determined by whole RV enzyme immunoassay were found to be significantly higher in males at weeks 2 and 4, suggesting brisker onset of recall AMI. Analysis of RV protein-specific IgG by immunoblot assays also revealed that while there were no notable sex differences in the distribution of E1-specific antibodies, more males produced E2-specific antibodies whereas more females produced C-specific antibodies after immunisation. Analysis of CMI with whole inactivated RV and a panel of RV synthetic peptides in lymphocyte proliferation assays revealed a brisker onset of CMI in males which paralleled that observed for AMI. The numbers of RV antigens recognised by males were significantly higher at weeks 2 and 4. Also, mean and median stimulation indices measured at weeks 2 and 4 for certain peptides, including two known to contain overlapping antibody neutralisation domains and T-cell epitopes, E1(213-239) and E1(254-285), were also found to be significantly higher in male subjects. These observations suggest that there are hormonal influences on RV-specific immunity which might result in differential handling of RV and, hence, may partially explain why females are more predisposed to adverse outcomes of rubella infection and immunisation. (+info)
Outbreak of aseptic meningitis associated with mass vaccination with a urabe-containing measles-mumps-rubella vaccine: implications for immunization programs.
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A mass immunization campaign with a Urabe-containing measles-mumps-rubella vaccine was carried out in 1997 in the city of Salvador, northeastern Brazil, with a target population of children aged 1-11 years. There was an outbreak of aseptic meningitis following the mass campaign. Cases of aseptic meningitis were ascertained through data collected from the records of children admitted to the local referral hospital for infectious diseases between March and October of 1997, using previously defined eligibility criteria. Vaccination histories were obtained through home visits or telephone calls. Eighty-seven cases fulfilled the study criteria. Of those, 58 cases were diagnosed after the vaccination campaign. An elevated risk of aseptic meningitis was observed 3 weeks after Brazil's national vaccination day compared with the risk in the prevaccination period (relative risk = 14.3; 95% confidence interval: 7.9, 25.7). This result was confirmed by a case series analysis (relative risk = 30.4; 95% confidence interval: 11.5, 80.8). The estimated risk of aseptic meningitis was 1 in 14,000 doses. This study confirms a link between measles-mumps-rubella vaccination and aseptic meningitis. The authors discuss the implications of this for the organization and planning of mass immunization campaigns. (+info)