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Biomedical subjects

M Knuf

Publications and source records attributed to M Knuf.

At least 19 recordsLinked to original sources

Identification of a novel compound heterozygote SCO2 mutation in cytochrome c oxidase deficient fatal infantile cardioencephalomyopathy.

UNLABELLED: Fatal infantile cardioencephalomyopathy (OMIM No. 604377) is a disorder of the mitochondrial respiratory chain and is characterised by neonatal progressive muscular hypotonia and cardiomyopathy because of severe Cytochrome c oxidase deficiency. Here we report a novel mutation in the Cytochrome c oxidase assembly gene SCO2 in an infant with fatal infantile cardioencephalomyopathy despite normal initial metabolic screening. CONCLUSION: In newborns with unexplained muscular hypotonia and cardiomyopathy genetic testing of mitochondrial respiratory chain disorders might be helpful to establish a final diagnosis and guide treatment decisions.

Cardiomyopathies↗

Assessment of nine candidate DTP-vaccines with reduced amount of antigen and/or without adjuvant as a fourth (booster-) dose in the second year of life.

BACKGROUND: The incidence of local reactions to diphtheria-, tetanus and acellular pertussis (DTaP-) vaccines in infants and toddlers increases with each subsequent dose, and entire thigh swellings (ETS) have been reported. Lowering the amount of antigen or of adjuvant may decrease the reactogenicity of DTaP while maintaining a protective immune response. OBJECTIVES: Following priming with three doses of a DTaP vaccine during infancy, the safety, reactogenicity and immunogenicity of nine different candidate DTaP-vaccines with reduced amounts of antigen and/or adjuvant given as fourth (booster) dose were evaluated. METHODS: Study participants were healthy infants aged 15-27 months at the time of booster vaccination. Each participant had received three doses of a DTaP vaccine (Infanrixtrade mark, GlaxoSmithKline, Rixensart, Belgium; "reference DTaP") at age 3, 4, and 5 months as part of a previous clinical trial. More than 20,000 children were eligible for participation in the current study protocol at the time. In a first phase at a University hospital-based vaccination study center, nine sequential cohorts of 63-119 study subjects received one of nine different candidate vaccines. Patients and study personal were blinded with regard to which vaccine was currently in use. Reactogenicity was solicited from parents using diary cards. Blood was drawn prior to and 4 weeks after vaccination and immediately centrifuged. The serum was stored at -20 degrees C until serology was performed by ELISA tests. As soon as the first candidate vaccine with adequate reactogenicity and immunogenicity profile was identified in the first study phase, a second study phase was initiated in parallel, to evaluate the safety and reactogenicity of the respective candidate vaccine in private practices in large cohorts (1613-2095 study subjects per group). RESULTS: In the first study phase, DTaP with no aluminum induced the highest frequency of ETS and fever. All other candidate vaccines caused lower rates of local and general reactions than the reference DTaP. As a general rule, vaccines with less antigen induced fewer reactions, although there was no strict dose-response effect and the difference, e.g. between a one-tenth and a one-fifth DTaP dose (DTaP 1/5; DTaP 1/10) was not clinically relevant. Separate injections of Td and aP caused fewer general reactions than the respective TdaP combination and local reactions were higher at the aP than at the Td injection site. Again, as a general rule, reduced amounts of antigen induced lower antibody concentrations, although all vaccines induced "protective" anti-tetanus and anti-diphtheria antibody responses. A total of 92-100% of children showed seroresponses to pertussis antigens even when vaccinated with reduced amounts of the respective pertussis antigen. Elimination of aluminum from DTaP vaccine induced higher anti-tetanus-antibody concentrations and so did a reduction of the amount of diphtheria antigen. Additional examples for antigen interaction were increased antibody concentrations, observed with injection of Td and aP into different limbs. In the second study phase, all three vaccines evaluated (one with a reduced amount of diphtheria antigen, TdaP; one with reduced amounts of all antigens, tdap; and one with a fifth dose of the reference vaccine (DTaP 1/5)) were safe and had an acceptable reactogenicity profile in a total of 4871 study subjects. CONCLUSIONS: Local reactions due to DTaP booster doses in the second year of life can be reduced by reducing the amount of antigen in the respective vaccine while an adequate immunogenicity is maintained. Aluminum-free vaccines induced ETS and fever most commonly. Any changes in vaccine composition should lead to a full evaluation of the new product.

Adjuvants, Immunologic↗

Immunogenicity, reactogenicity and safety of a 7-valent pneumococcal conjugate vaccine (PCV7) concurrently administered with a DTPa-HBV-IPV/Hib combination vaccine in healthy infants.

BACKGROUND: To evaluate immunogenicity, reactogenicity, and safety of a hexavalent combination vaccine diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated polio virus-Haemophilus influenzae type b (DTPa-HBV-IPV/Hib) when coadministered with a 7-valent pneumococcal conjugate vaccine (PCV7). METHODS: Infants received either a hexavalent diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated polio virus-H. influenzae type b vaccine concomitantly with PCV7 or DTPa-HBV-IPV/Hib alone infants were vaccinated at 2, 3 and 4 months (primary immunization) and 12-15 months of age (booster dose). Local and systemic reactions and adverse events were monitored following each dose and compared between groups. Blood was obtained prior to dose 1, one month after dose 3, immediately prior to and 1 month following the booster dose to measure antibody responses to each of the antigens. RESULTS: Two hundred and fifty-three subjects (PCV7, 127; Control, 126) were enrolled. Antibody responses were compared in 226 subjects for the primary immunization and 212 for the booster dose (per-protocol (PP) population). Although there were some differences in geometric mean concentrations (GMCs) to the DTPa-HBV-IPV/Hib antigens after the primary series, GMCs for all antigens after the booster dose were similar in both groups, except for diphtheria which was significantly higher in the PCV7 group (PCV7, 7.41 IU/mL; Control, 5.78 IU/mL). Reactogenicity and safety data were compared in 252 infants receiving primary immunization and 235 children receiving the booster dose. Site reactions were similar in both groups. Fever >or=38.0 degrees C following each vaccination was reported more frequently in the PCV7 group (28.3-50.0%) than in the Control group (15.6-33.6%) whereas fever >39.0 degrees C occurred only in a few cases and to the same extent in both groups (PCV7, 0.8-2.7%; Control, 1.6-4.1%). Only one reported serious adverse event was characterized as being related to the study vaccines: control subject was hospitalized with a fever. CONCLUSION: DTPa-HBV-IPV/Hib and PCV7 were highly immunogenic, well-tolerated and safe when coadministered at 2, 3 and 4 months of age with a booster dose at 12-15 months of age. These results support the coadministration of PVC7 with DTPa-HBV-IPV/Hib as part of the routine immunization schedule for infants and children.

Antibody Formation↗

Cell mediated and antibody immune response to inactivated hepatitis A vaccine.

The humoral and cellular immune response to inactivated hepatitis A vaccine was investigated dynamically in a time elapse study over 1 year. Fourty-five healthy volunteers, seronegative for anti-HAV, were vaccinated with 1440 enzyme-linked immunosorbent assay units (EU) of formalin-inactivated hepatitis A virus following a 0--6-month schedule. Serum anti-HAV levels and HAV-specific proliferation of peripheral blood mononuclear cells were measured at several time points over a 26- and 28-week period after the first and second injection, respectively. Distinct B and T cell responses were determined within 14 days after primary vaccination. The booster vaccination-induced immediate peak levels for the humoral (anti-HAV GMC=5376mIU/ml) as well as the cellular (median Deltacpm=14173cpm) response.

Adult↗

Booster vaccination with hexavalent DTPa-HBV-IPV/Hib vaccine in the second year of life is as safe as concomitant DTPa-IPV/Hib + HBV administered separately.

The safety and reactogenicity of a booster dose of GSK Biologicals' hexavalent DTPa-HBV-IPV/Hib vaccine (N=4725) was compared with the separate administration of GSK Biologicals' DTPa-IPV/Hib and HBV vaccines (N=4474) in two open, randomized multicenter studies (A and B). Solicited symptoms occurring within 4 days of vaccination were recorded on diary cards and serious adverse events (SAEs) were collected throughout the study period. In Study A (N=1149), incidences of solicited symptoms were similar in both groups; there were no SAEs either reported within 4 days of vaccination or considered to be causally related to vaccination. In study B (N=8050), where fever was the only solicited symptom, rectal temperature > or =39.5 degrees C was observed in 2.5% and 2.8% of the subjects, respectively. Fever > or =40.0 degrees C was rare (0.6%), and only two cases of febrile convulsions were recorded during the 4 days following vaccination both in the control group. Large swelling reactions (defined as local injection site swelling with diameter >50 mm, noticeable diffuse injection site swelling or noticeable increased circumference of the injected limb) were reported following 2.3% of the booster vaccine doses, regardless of the vaccine used. Extensive swelling reactions involving an adjacent joint were reported in 0.1% of the subjects. Two SAEs, both reported after booster doses of DTPa-IPV/Hib and HBV vaccines administered separately, were considered by the investigators to be related to vaccination. Both resolved completely without sequelae. The hexavalent DTPa-HBV-IPV/Hib vaccine and the DTPa-IPV/Hib and HBV vaccines administered separately have similar good reactogenicity and safety profiles when given as booster doses in the second year of life.

Confidence Intervals↗

The right ventricle in Fabry disease.

AIM: Left ventricular (LV) hypertrophy is a common feature in Fabry disease-related progressive infiltrative hypertrophic cardiomyopathy and affects both men and women, but at different ages. To date, however, little is known about the role of right ventricular (RV) function in Fabry disease. Therefore, this study aimed to investigate the extent of RV involvement in patients with Fabry disease. METHODS: Echocardiographic examination of the right and left ventricle was carried out in 129 patients (80 women and 49 men) with Fabry disease. RESULTS: RV hypertrophy was present in 46 patients (35.7%). Of these patients, 13 showed signs of severely depressed right systolic function (tricuspid annulus movement < 10 mm and a prolonged RV pre-ejection period/pulmonary ejection time ratio) and six patients showed additional severe depression of parameters of diastolic function (pseudo-normal or restrictive RV filling pattems). Those patients with RV hypertrophy and severely compromised systolic and diastolic function had the highest LV masses (92 +/- 11.7 g/m(2.7)). CONCLUSION: RV involvement is common in Fabry disease and ultimately progresses to severe systolic and diastolic RV dysfunction. These findings might explain why patients with preserved LV function can develop clinical features such as reduced exercise capacity, organomegaly and lymphoedema.

Adult↗

Safety, reactogenicity and immunogenicity of a combined hexavalent tetanus, diphtheria, acellular pertussis, hepatitis B, inactivated poliovirus vaccine and Haemophilus influenzae type b conjugate vaccine, for primary immunization of infants.

Safety, reactogenicity and immunogenicity of GSK Biologicals' hexavalent DTPa-HBV-IPV/Hib vaccine (Infanrix)hexa) was assessed when used for primary vaccination at 3, 4 and 5 months of age (N = 2163), compared to the separate administration of DTPa-IPV/Hib and HBV vaccines (N = 720). A similar safety and reactogenicity profile was demonstrated for both vaccine regimens, as well as a good immune response for all antigen components. By offering protection against six diseases in a series of single injections, the hexavalent DTPa-HBV-IPV/Hib vaccine was shown to be a safe, well tolerated and immunogenic alternative to primary immunization with licensed separately administered vaccines.

Bacterial Capsules↗

Flow-cytometric DNA analysis of intracranial tumors in children.

The objective of this study was to investigate flow-cytometric DNA values of pediatric intracranial tumors, and to establish DNA analysis as a potential prognostic parameter. Twenty-nine brain tumor specimens from 26 pediatric patients were cryo-preserved within a 3-year period. The DNA content was measured by flow cytometry. Six of the tumor specimens had aneuploid DNA patterns. The median of the proliferation index was lower in the survivor group compared with the non-survivor group (36.4% and 47.5%, respectively). Ten of the 26 patients are still alive, eight were lost to follow up, and eight died. Flow-cytometric DNA analysis may be a helpful tool for examining brain tumors in children. The small size of this study could not establish flow cytometry as a definite prognostic factor, but further prospective multicenter studies will evaluate the prognostic significance of flow-cytometric DNA analysis.

Adolescent↗

[Sense and nonsense of exposure prophylaxis in communal club installations for children and adolescents -- a contribution to the implementation of the German Defence Against Infection law from a point of view of preventive paediatrics].

The protection against infections in facilities of the community for infants and children, such as kindergarten, schools and training centres, results first of all from the vaccination practice and hygiene practices. Pertussis, varicella and tuberculosis are examples for this. In some cases the transient avoidance of contacts and the intensified integration of the parents could contribute to the prevention of an infection, e. g. strepptococcus A infections and head louses. The consequential realization of the recommendation of the STIKO (expert panel for vaccination guidelines; http://www.rki.de/GESUND/STIKO/STIKO.HTM) is one of the main pillars of protection by vaccination. Vaccine coverage may also be improved by including these paragraphs in the statutes of day nurseries. Before integration of children into such facilities it should be necessary to verify that there are no doubts about the health conditions. This could be confirmed by presenting the vaccination or check-up card.

Adolescent↗

Primary vaccination of infants with diphtheria-tetanus-acellular pertussis-hepatitis B virus- inactivated polio virus and Haemophilus influenzae type b vaccines given as either separate or mixed injections.

OBJECTIVE: The aim of this open, multicenter, randomized trial was to evaluate the immunogenicity and reactogenicity of a candidate combined diphtheria-tetanus-acellular pertussis-hepatitis B virus-inactivated polio virus (DTaP-HBV-IPV) vaccine when given as either a mixed or as separate concomitant injections with Haemophilus influenzae type b (Hib) vaccine. STUDY DESIGN: A total of 359 subjects were randomized to receive either DTaP-HBV-IPV/Hib (mixed administration - 180 subjects) or DTaP-HBV-IPV + Hib (separate administration in opposite limbs - 179 subjects) at 2, 3, and 4 months of age. RESULTS: After vaccination, seroprotective antibody concentrations against diphtheria, tetanus, hepatitis B, and polio viruses and a high (> or = 97%) pertussis vaccine response were seen in almost all study participants. All subjects except one in the mixed administration group had postvaccination Hib anti-PRP antibody concentrations > or = 0.15 microg/mL. Of subjects in the mixed and separate group, 77.2% (geometric mean antibody concentration, 2. 62 microg/mL) and 88.6% (geometric mean antibody concentration, 4.45 microg/mL) had Hib anti-PRP concentrations > or = 1 microg/mL, respectively. The addition of the Hib component to the 5-component vaccine did not increase the incidence of local or general reactions. CONCLUSION: Both administrations of the candidate vaccine were found to be safe, immunogenic, and well tolerated. Although anti-PRP geometric mean antibody concentrations and the percent of subjects achieving the 1 microg/mL seroprotective level were lower after the mixed administration, they were in the range seen with monovalent Hib vaccines or with other DTaP-based/Hib combinations licensed in some European countries. Therefore both administrations have the potential to simplify childhood immunization.

Antibody Formation↗

Normal values of M mode echocardiographic measurements of more than 2000 healthy infants and children in central Europe.

OBJECTIVE: To obtain normal M mode (one dimensional) echocardiographic values in a substantial sample of normal infants and children. DESIGN: Data were obtained over three years from a single centre in central Europe. PATIENTS: 2036 healthy infants and children aged one day to 18 years. METHODS: In line with recommendations for standardising measurements from M mode echocardiograms, and using digital echocardiographic equipment, measurements were obtained of the following: right ventricular anterior wall thickness at end diastole, right ventricular end diastolic dimension, thickness of interventricular septum at end diastole and end systole, thickness of posterior wall of the left ventricle at end diastole and end systole, left ventricular dimension at end diastole and end systole, pulmonary and aortic valve diameter, and left atrial dimension. RESULTS: Measurements are presented graphically on centile charts with respect to body surface area, and as tables with mean and 2 SD values for newborns in relation to body weight, and for infants and children in relation to body surface area. Best fitting regression equations are given for each measured variable, using the 50th centile values. CONCLUSION: In comparison with previously published normal values, the presented charts and tables make it possible to judge echocardiographic measurements of a particular patient as normal or abnormal.

Adolescent↗

Cellular immune response of a varicella vaccine following simultaneous DTaP and VZV vaccination.

BACKGROUND: Chickenpox and zoster are an important cause of morbidity among children and adults. The ability of a new, thermostable vaccine to induce varicella-zoster-virus (VZV)-specific humoral and cell mediated immunity when given simultaneously with diphtheria-tetanus-acellular pertussis vaccine (DTaP) as a booster dose in the second year of life was investigated. METHODS: A new, temperature stable varicella vaccine (OKA-strain, SB-Biologicals, Rixensart, Belgium) was given simultaneously with a booster dose of DTaP vaccine. VZV-specific humoral and cell-mediated immunity was studied in the first 27 out of 232 vaccinated children at 16-28 months of age, from blood samples drawn just before and six weeks after vaccination. VZV-specific antibody response, T-cell proliferation, cytokine production and expression of activation markers (CD25, HLADR) on T-cells were analyzed. RESULTS: Vaccination resulted in a significant rise of VZV-specific serum IgG titers and in a strong VZV-specific T-cell response in all vaccinated infants. Analysis of the expression of activation marker revealed activation of both CD4+-T-helper- and CD8+-T-cells. CONCLUSIONS: The varicella vaccine given simultaneously with DTaP produced strong B- and T-cell responses alike. This is the first report to show that CMI to VZV is conferred to young children by vaccination with a temperature stable VZV vaccine.

Antibodies, Viral↗

The interaction of buccal mucosal epithelial cells with E. coli bacteria enhances the intraepithelial calcium flux and the release of prostaglandin E2 (PgE2).

Mucosal epithelial cells contribute significantly to host defense mechanisms. Uroepithelial cells (UEC) from healthy donors suppress bacterial growth in vitro. Bacterial adherence to UEC has been shown to be a prerequisite. Similar results have been shown for buccal epithelial cells (BEC). The host response triggered by the host-parasite interaction seems to involve signal transduction and intracellular activation of second messengers. In this study the intraepithelial calcium flux was analyzed in individual BEC after bacterial contact. BEC were derived from scrapes of the buccal mucosa and labelled with fluo-3 (a calcium indicator). Thereafter the cells were analyzed immediately with a FACscan flowcytometer. The intracellular events were evaluated before and after the addition of viable E. coli bacteria (strain 4389, K1O1H7, pili II pos.). For control, the influence of prostaglandins, histamine, PMA, LPS and opsonized avital E. coli on the epithelial calcium flux was investigated. Additionally, supernatants of BEC-E. coli cocultures were analyzed with respect to their PgE2 content. PgE2 concentrations in supernatants of BEC, cultured alone or together with E. coli, were measured by a commercial PgE2 ELISA kit. The addition of vital E. coli to BEC was promptly answered by a significant intracellular calcium flux. PgE2, histamine and PMA, but not PgF2alpha, PgE1, LPS and opsonized E. coli, increased intracellular calcium. BEC alone did not release PgE2. After coculture with E. coli increased levels of PgE2 were measured in the supernatants. PgE2 release was still enhanced by coactivation of the BEC with phorbolester (PMA). Our results confirm that calcium flux in mucosal epithelial cells is stimulated by the cell-bacteria contact. We suggest that the increased PgE2 release amplifies the stimulation of intraepithelial second messengers. The resulting cell activation may lead to the secretion of antimicrobial peptides, thereby contributing to the regulation of mucosal host resistance to bacterial infections.

Adult↗

Adjustable tourniquet to manipulate pulmonary blood flow after Norwood operations.

BACKGROUND: Survival after first-stage palliative Norwood operations for single ventricle with systemic outflow obstruction is mainly dependent on a balanced ratio of pulmonary blood flow to systemic blood flow. Here we report the clinical results using a modified technique that allows a controlled systemic-to-pulmonary shunt flow to prevent pulmonary overcirculation. METHODS: From 1995 to 1998, of 26 infants undergoing first-stage palliative Norwood operations, 7 had placement of an adjustable tourniquet around a modified right Blalock-Taussig shunt. RESULTS: Hospital survival was 20 of 26 patients (77%). All 7 patients in whom snaring of the shunt was indicated survived. Two patients underwent repeated adjustment, in 5 patients the tourniquet could be removed during delayed sternal closure, and 2 patients were discharged with the shunt partially snared. CONCLUSIONS: The snare-controlled systemic-to-pulmonary shunt allows improved hemodynamic stability after reconstructive surgery for hypoplastic left heart syndrome or other similar complex cardiac defects by reducing the risk of pulmonary overcirculation. It is simple and rapidly executed. The option of graded banding of the shunt depending on the hemodynamic situation increases flexibility and safety after cardiopulmonary bypass or at any time in the postoperative period.

Cardiac Surgical Procedures↗

Immunogenicity and reactogenicity of a Haemophilus influenzae type b tetanus conjugate vaccine when administered separately or mixed with concomitant diphtheria-tetanus-toxoid and acellular pertussis vaccine for primary and for booster immunizations.

UNLABELLED: With an increasing number of new vaccines available for routine childhood immunization, combination vaccines are needed in order to maintain or achieve a high compliance with recommended immunization programmes. In a prospective, randomized, comparative, multi-centre study, 822 healthy infants were enrolled to receive three doses of either a candidate or a commercially available Haemophilus influenzae type b (Hib) vaccine concomitantly with diphtheria-, tetanus- acellular pertussis (DTaP) vaccine. Study subjects were randomly allocated to one of the following groups: (1) separate, or (2) mixed injection of DTaP and candidate Hib vaccine, or (3) separate injection of DTaP and commercial Hib vaccine. One year later the first 189 study subjects received either separate or mixed injections of the same Hib and DTaP vaccines as booster doses. Evaluation of reactogenicity was based on diary cards completed by parents. Immunogenicity was documented by measuring IgG antibody concentrations in serum samples taken before and 4 weeks after primary and booster vaccination. No serious adverse events occurred and most local and systemic reactions were mild to moderate. Booster doses were more reactogenic than primary doses with all groups. Antibody concentrations against pertussis antigens were similar to those seen with DTaP alone. All but one subject had protective antibody concentrations against diphtheria and tetanus. Primary immune response to the Hib vaccine was significantly lower in the group receiving the mixed Hib-DTaP vaccine, however, > or = 95% of vaccinees had anti-Hib antibody concentrations > or = 0.15 microg/ml and there was a marked booster response (> 100-fold) in all groups. CONCLUSIONS: Mixing DTaP and Hib vaccines for primary immunization caused a decrease in anti-Hib antibody response, although after primary immunization as after booster doses, all subjects showed antibody concentrations considered to be protective for invasive Hib disease. Mixing of the vaccines did not result in increased reactogenicity.

Analysis of Variance↗

Evidence for induction of polysaccharide specific B-cell-memory in the 1st year of life: plain Haemophilus influenzae type b-PRP (Hib) boosters children primed with a tetanus-conjugate Hib-DTPa-HBV combined vaccine.

UNLABELLED: The lack of an adequate immune response to the major polysaccharide of the Haemophilus influenzae type b (Hib) capsule (polyribosyl ribitol phosphate) (PRP) in very young infants (< 18 months) can be overcome by conjugating PRP to a T-cell dependent carrier protein. We studied whether administration of a tetanus-PRP conjugate vaccine reconstituted with a diphtheria-tetanus-acellular pertussis-hepatitis B (DTPa-HBV) vaccine as a three dose primary course at 3, 4 and 5 months of age induced PRP-specific immunological memory, by examining the anti-PRP response to a dose of unconjugated PRP given with the DTPa-HBV booster approximately 1 year later. The unconjugated PRP elicited protective anti-PRP antibody levels (> or = 0.15 microgram/ml) in all but 3 of the 369 vaccinees, including 13 infants who failed to demonstrate a measurable immune response after the primary course. In a sub-cohort of 54 subjects all had anti-PRP levels > or = 0.5 microgram/ml within 7-14 days of the booster showing a rapid anamnestic type response. Both primary and booster responses were predominantly IgGl indicating a T-cell dependent response. The DTPa-HBV components elicited protective anti-diphtheria, anti-tetanus and anti-HBs antibody levels in > or = 98.5% of vaccinees, and immune responses to each of the acellular pertussis vaccine components in 92.3%-97.3% of subjects. CONCLUSION: The tetanus-PRP conjugate vaccine not only elicited a good primary humoral response, but also induced immunological memory so that the infants were able to mount a large and rapid immune response to subsequent exposure to plain PRP, indicating that protection against circulating wild-type Hib had been generated. Successful induction of immunological memory occurred even when there was no measurable humoral anti-PRP response to the primary course. Tetanus-PRP conjugate vaccine can be used in combination with DTPa-HBV vaccine, when administered separately or as a single injection in the same syringe, in primary immunisation schedules at 3, 4 and 5 months of age.

Age Factors↗

Reactogenicity and immunogenicity of a booster dose of a combined diphtheria, tetanus, and tricomponent acellular pertussis vaccine at fourteen to twenty-eight months of age.

OBJECTIVES: The primary objective was to assess the nature and incidence of adverse events after a fourth dose of a tricomponent acellular pertussis-diphtheriatetanus vaccine given in the second year of life after primary vaccination with the same vaccine at 3, 4, and 5 months of age. A secondary objective was to analyze the immunogeniecity of the booster vaccination. DESIGN: Of the 5361 children enrolled (aged 14 to 28 months), adverse reactions were specifically solicited from the first 1863 enrollees for the first 4 days after vaccination and then were unsolicited for the remainder of the 4 weeks of follow-up (group 1). In the next 3498 subjects, safety and reactogenicify were entirely unsolicited for this 4-week period (group 2). Immunogenicity was analyzed by means of prebooster and postbooster serum antibody titers for all vaccine components in a random subgroup of 197 children from group 1. RESULTS: Soliciting symptoms elicited reports of at least one symptom in 1314 of 1809 children in group 1 (72.6%), including 993 (54.9%) with local and 885 (48.9%) with general symptoms during the first 4 days after vaccination. When symptoms were gathered in an unsolicited fashion, only 580 of 3498 children in group 2 (16.6%) had a reported symptom during this time, consisting of 344 (9.8%) local and 319 (9.1%) general symptoms, respectively. An unsolicited symptom, areactive edematous swelling of the whole thigh, occurred in 62 children (1.1%), with 45 and 17 reports in groups 1 and 2, respectively. The vast majority of all reported symptoms were mild to moderate, and all children recovered without sequelae. Fourteen serious adverse events were reported, but none was considered to be related to the vaccination. Immunogenicity analysis showed a vaccine response to pertussis toxin in 99.5% of subjects, to filamentous hemagglutinin in 98.5%, and to pertactin (69 kd outer membrane protein) in 99%. All subjects had postvaccination antibody titers of 0.1 IU/ml or greater against diphtheria and tetanus toxoids.

Antibody Formation↗