Protection against varicella in family contacts by immediate inoculation with live varicella vaccine. Varicella vaccine studies in healthy children and adults. No evidence of an increase of bacterial and viral infections following Measles, Mumps and Rubella vaccine. A randomized trial of the effectiveness of computer-generated telephone messages in increasing immunization visits among preschool children. Risk of serious neurologic disease after immunization of young children in Britain and Ireland. Protective effect of single-dose adjuvanted pandemic influenza vaccine in children. Illness after measles-mumps-rubella vaccination. Efficacy of postexposure immunization with live attenuated varicella vaccine in the household setting--a pilot study. Use of an inactivated varicella vaccine in recipients of hematopoietic-cell transplants.
A live varicella vaccine (Oka strain) was given to susceptible household contacts of varicella to test the protective efficacy of the vaccination. Twenty-six contacts of 21 families were vaccinated, usually within three days after onset of the index cases. None of the vaccinated children developed clinical symptoms of varicella. Eighteen of 24 sera obtained before vaccination were found to be seronegative by complement fixation and neutralization tests. Seroconversion was observed in all of the 18. On the other hand, all of 19 unvaccinated contacts in the 15 families, who served as controls, showed typical manifestations of varicella from 10 to 33 days after onset of the index varicella cases. In three families, where only one sibling contact received vaccine and the other was an unvaccinated control, none of the vaccinated children showed any clinical symptoms while unvaccinated controls exhibited typical varicella symptoms 10 to 14 days after the onset of the index cases. These results indicate that varicella is prevented in household contacts by vaccination within three days following exposure. Immunization of normal children and adults with Oka strain live varicella vaccine from several manufacturers has been studied in our laboratory and elsewhere. This paper summarizes clinical trials designed to obtain information on minimum dose immunogenicity pre- and postexposure prophylaxis, immunization of various age groups, and booster immunizations for seropositive individuals. These studies documented a 94% to 100% seroconversion rate with 95% to 100% persistence of antibodies at 3 to 4 years. Protective efficacy was more than 90%, and the vaccine was successful in preventing varicella when a high dose was given postexposure. Clinical reactions were limited to temperature elevations and minor papulovesicular rashes that occurred in 5% to 10% of vaccinees. Herpes zoster has been absent in vaccinated healthy individuals. The suggestion that multi-antigen vaccines might overload the immune system has led to calls for single antigen vaccines. In 2003 we showed that rather than an increase there appeared to be a reduced risk of severe bacterial infection in the three months following Measles, Mumps and Rubella vaccine (MMR). The present analysis of illnesses in a general population is based on an additional 10 years of data for bacterial infections and also includes admissions with viral infections. Analyses were carried out using the self-controlled case-series method and separately for bacterial and viral infection cases, using risk periods of 0-30 days, 31-60 days and 61-90 days post MMR vaccine. An analysis was also carried out for those cases which were given MMR and Meningococcal serogroup C (MCC) vaccines concomitantly. A reduced risk was seen in the 0-30-day period for both bacterial infection (relative incidence=0.68, 95% CI 0.54-0.86) and viral infections (relative incidence=0.68, 95% CI 0.49-0.93). There was no increased risk in any period when looking at combined viral or bacterial infections or for individual infections with the single exception of an increased risk in the 31-60 days post vaccination period for herpes infections (relative incidence=1.69, 95% CI 1.06-2.70). For the children given Meningococcal group C vaccines concomitantly no significantly increased risk was seen in either the bacterial (relative incidence=0.54, 95% CI 0.26-1.13) or viral cases (relative incidence=0.46, 95% CI 0.11-1.93). Our study confirms that the MMR vaccine does not increase the risk of invasive bacterial or viral infection in the 90 days after the vaccination and does not support the hypothesis that there is an induced immune deficiency due to overload from multi-antigen vaccines. To assess the effectiveness of computer-generated telephone reminder and recall messages in increasing preschool immunization visits.
                Randomized, controlled trial.
                Fourteen counties in urban and rural Georgia.
                Children (N = 8002) who were younger than 2 years; had telephone numbers listed in preexisting computerized immunization databases; and were due or late for immunization(s) during the 4-month enrollment period.
                Households of children were randomized to receive or not receive a general or vaccine-specific computer-generated telephone reminder or recall message the day before the child was due, or immediately after randomization if the child was late.
                The rates of immunization visits during the 30-day follow-up period.
                Of the 4636 children whose households were randomized to receive a message, 1684 (36.3%) visited the health department within 30 days compared with 955 (28.4%) of the 3366 children whose households were not contacted (risk ratio [RR] = 1.28; 95% confidence interval [CI] = 1.20 to 1.37; P < .01). Immunization visits were more frequent (41.1%) among the 3257 children whose households actually received the message (RR = 1.45; 95% CI = 1.36 to 1.56; P < .01). Improvement in immunization visits was similar for general and specific messages, greater for recall than reminder messages, and greatest for children who were late for the third dose of the diphtheria-tetanus-pertussis vaccine and the measles-mumps-rubella vaccine.
                These data suggest a simple and effective way to increase preschool immunization visits, particularly for vaccines associated with the lowest immunization rates. We sought to investigate the risk of serious neurologic disease after immunization in early childhood.
                The results of a 3-year prospective study of children (2-35 months old) in Britain and Ireland with encephalitis and/or severe illness with convulsions and fever were linked to each child's vaccine history. Cases were reported via the British Paediatric Surveillance Unit's network. The self-controlled case-series method was used to investigate associations between immunization and acute potential adverse events. The risk periods investigated were 0 to 3 and 0 to 7 days post-diphtheria, tetanus, whole cell pertussis, Haemophilus influenzae type b or meningococcal C conjugate vaccine and 6 to 11 and 15 to 35 days post-measles, mumps, rubella vaccine.
                A total of 157 disease episodes from 155 children met the analytical case definition. There were 11 cases of herpes simplex encephalitis and 23 cases of primary human herpesvirus 6 and/or 7 infection. There was no evidence of a raised relative incidence of serious neurologic disease in any of the specified risk periods with the exception of a raised relative incidence of 5.68 in the 6-11 days after measles, mumps, rubella vaccine. Based on this relative incidence, between 3 and 6 of the 6 cases in this period were estimated to be attributable to the vaccine with a best estimate of 5. The 6 cases all had fever with convulsions lasting >30 minutes; in all but 1, there was complete recovery by discharge from hospital. Of the 5 patients who recovered, 1 had a concurrent primary human herpesvirus 6 infection and one a primary human herpesvirus 7.
                Six to 11 days after measles, mumps, rubella vaccine there is an increased risk of fever and convulsions lasting >30 minutes. All 6 of the episodes temporally related to immunization met the criteria for complex febrile convulsions. The estimated attributable risk of serious neurological disease was similar to that previously found for measles vaccine. During the first wave of A/California/7/2009(H1N1) influenza, high rates of hospitalization in children under 5 years were seen in many countries. Subsequent policies for vaccinating children varied in both type of vaccine and number of doses. In Canada, children 36 months to <10 years received a single dose of 0.25 ml of the GSK adjuvanted vaccine (Arepanrix) equivalent to 1.9 microg HA. Children 6 months to 35 months received two doses as did those 36-119 months with chronic medical conditions.
                We conducted a community-based case-control vaccine effectiveness (VE) review of children under 10 years with influenza like illness who were tested for H1N1 infection at the central provincial laboratory. Laboratory-confirmed influenza was the primary outcome, and vaccination status the primary exposure to assess VE after a single 0.25-ml dose.
                If vaccination was designated to be effective after 14 days, no vaccinated child had laboratory-confirmed influenza compared to 38% of controls. The VE of 100% was statistically significant for children <10 years of age and <5 years considered separately. If vaccination was considered effective after 10 days, VE dropped to 96% overall but was statistically significant and over 90% in all age subgroups, including those under 36 months.
                A single 0.25-ml dose of the GSK adjuvanted vaccine (Arepanrix) protects children against laboratory-confirmed pandemic influenza potentially avoiding any increased reactogenicity associated with second doses. Adjuvanted vaccines offer hope for improved seasonal vaccines in the future. To provide accurate information on the common sequelae of measles-mumps-rubella (MMR) vaccination and to compare post-vaccine symptoms in children vaccinated at 13 and 15 months.
                Prospective cluster randomized controlled trial.
                Twenty-two family practices in southwestern Ontario.
                All 376 infants who were due to receive MMR vaccine in the next year, 253 (67.3%) successfully completed the study.
                MMR vaccine administered at 13 months by half of the family physicians and at 15 months by the remaining half.
                Family physician's physical findings in children 7 days and 30 days after vaccine; reported illnesses by mothers in a daily diary in the month before and after vaccination and medical records of visits to family physicians and hospital admissions in the month before and after vaccination.
                Compared with the incidence rates in the corresponding weeks before vaccination, the rates of lymphadenopathy (23.8%) and fever (16.8%) were higher 1 week afterward and the rate of rash (26.9%) was higher 7 to 14 days afterward. Fewer health problems were reported in the third and fourth weeks after vaccination than in the corresponding weeks beforehand. Hospital admissions after vaccination were no more frequent than those before once cause and time of admission were taken into account. The two age groups did not differ in any of the outcomes.
                Mothers should be informed about the possibility of increased physical findings in the weeks after MMR vaccination, especially lymphadenopathy, nasal discharge and rash. Since the occurrence of sequelae does not seem to differ significantly between 13-month-old recipients and 15-month-old recipients, it should not influence the decision of when to administer the vaccine. The aim of the present study was to examine the efficacy of postexposure vaccination with Varilrix in the household setting. A randomized, double-blind, placebo-controlled design was used. Twenty-two children received the varicella vaccine and 20, a placebo. The relative risk of developing varicella with a placebo compared with the vaccine was 1.1 (95% confidence interval 0.55-2.21). The risk of developing moderate to severe disease was eight times greater in the placebo group (RR=8), indicating an 80% protective effect against moderate/severe disease. The varicella vaccine Varilrix may not be effective in preventing varicella when administered after household exposure, although it is highly effective in ameliorating the disease in those who acquire it under these circumstances. The reactivation of varicella-zoster virus from latency causes zoster and is common among recipients of hematopoietic-cell transplants.
                We randomly assigned patients who were scheduled to undergo autologous hematopoietic-cell transplantation for non-Hodgkin's or Hodgkin's lymphoma to receive varicella vaccine or no vaccine. Heat-inactivated, live attenuated varicella vaccine was given within 30 days before transplantation and 30, 60, and 90 days after transplantation. The patients were monitored for zoster and for immunity against varicella-zoster virus for 12 months.
                Of the 119 patients enrolled, 111 received a transplant. Zoster developed in 7 of 53 vaccinated patients (13 percent) and in 19 of 58 unvaccinated patients (33 percent) (P=0.01). After two patients in whom zoster developed before transplantation were excluded, the respective rates were 13 percent and 30 percent (P=0.02). In vitro CD4 T-cell proliferation in response to varicella-zoster virus (expressed as the mean stimulation index) was greater in patients who received the vaccine than in those who did not at 90 days, after three doses (P=0.04); at 120 days, after all four doses (P<0.001); at 6 months (P=0.004); and at 12 months (P=0.02). The risk of zoster was reduced for each unit increase in the stimulation index above 1.6; a stimulation index above 5.0 correlated with greater than 93 percent protection. Induration, erythema, or local pain at the injection site was observed in association with 10 percent of the doses.
                Inactivated varicella vaccine given before hematopoietic-cell transplantation and during the first 90 days thereafter reduces the risk of zoster. The protection correlates with reconstitution of CD4 T-cell immunity against varicella-zoster virus.
These small trials suggest varicella vaccine administered within three days to children following household contact with a varicella case reduces infection rates and severity of cases. No RCTs for adolescents or adults were identified. However safety was not adequately addressed.