The Experts below are selected from a list of 69 Experts worldwide ranked by ideXlab platform
K Hoppenbrouwers - One of the best experts on this subject based on the ideXlab platform.
-
The effect of reconstitution of an Haemophilus influenzae type b-tentanus toxoid conjugate (PRP-T) Vaccine on the immune responses to a diphtheria-tetanus-whole cell pertussis (DTwP) Vaccine: a five-year follow-up.
Vaccine, 1999Co-Authors: K Hoppenbrouwers, M Roelants, C Vandermeulen, C Ethevenaux, J Knops, J DesmyterAbstract:Controversial results have been obtained from previous studies on the combined administration of Haemophilus influenzae type b-tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-whole-cell pertussis (DTwP) combination Vaccines, with regard to possible reciprocal interference between the constituent antigens. To document the priming effect and possible long-term immunogenic interference of PRP-T and DTwP combination Vaccines, a randomized, double-blind, controlled study was conducted in Belgium. A total of 168 healthy infants received, at 3, 4 and 5 months of age, DTwP Vaccine mixed just prior to injection either with PRP-T Vaccine (group A, DTwP//PRP-T, N = 85) or with placebo (group B, DTwP//Placebo, N = 83). At the age of 14 months, children of both groups were randomized to receive either a dose of DTwP//PRP-T Vaccine (subgroups A1 and B1) or a dose of Hib polysaccharide (PRP) Vaccine (subgroups A2 and B2). Those children in subgroups A1 and B1 had an additional serum sample taken at the age of 5 years (at the time of a DT booster). The immune response to Hib polysaccharide at the age of 4, 5 and 6 months confirmed the excellent immunogenicity profile of PRP-T in infants. In addition, the vigorous anamnestic response (i.e. a 20-fold increase of GMT) to a booster dose of the plain capsular polysaccharide (PRP) reflected the efficient Hib-priming induced by the combined DTwP//PRP-T Vaccine. Reconstitution of PRP-T with DTwP did not affect the immune response to diphtheria toxoid or pertussis agglutinins. Nevertheless, at almost any time point during the five-year follow-up, the tetanus antitoxin GMT values were significantly lower in the DTwP//PRP-T group (A and A1) than in the DTwP//Placebo group (B and B1). Despite the suppressive effect on GMT values, intergroup differences in rates of seroprotection were never significant, except after doses 2 and 3 for which there were lower percentages of children in group A with antitoxin titers > 0.05 IU/mL and > 1.0 IU/mL. In the group primed with the combined DTwP//PRP-T Vaccine, (1) a DT booster dose at the age of 5 years provoked a 150-fold increase in tetanus antitoxin GMT, (2) a high tetanus antitoxin GMT value was attained (GMT = 19.3 IU/mL) and (3) all children in this group had tetanus antitoxin titers > 1.0 IU/mL, so it may be concluded that all these children will still be protected against tetanus until at least the age of the next recommended booster dose (i.e. the age of 15 years). No differences in the occurrence of adverse events were observed between the groups who received the DTwP//PRP-T Vaccine or the DTwP//Placebo Vaccine, both Vaccines being associated with events customarily attributable to DTwP (data not shown). Our results indicate (1) that the combination Vaccine, DTwP//PRP-T, represents a safe and effective alternative for the existing uncombined Vaccines and (2) that the long-term effect of interference between the components of future combination Vaccines should be studied with subsequent booster doses, followed by the evaluation of persistence of antibodies over several years.
-
The effect of reconstitution of an Haemophilus influenzae type b-tetanus toxoid conjugate (PRP-T) Vaccine on the immune responses to a diphtheria–tetanus-whole cell pertussis (DTwP) Vaccine: a five-year follow-up
Vaccine, 1999Co-Authors: K Hoppenbrouwers, M Roelants, C Vandermeulen, C Ethevenaux, J Knops, J DesmyterAbstract:Abstract Controversial results have been obtained from previous studies on the combined administration of Haemophilus influenzae type b-tetanus toxoid conjugate (PRP-T) and diphtheria–tetanus-whole-cell pertussis (DTwP) combination Vaccines, with regard to possible reciprocal interference between the constituent antigens. To document the priming effect and possible long-term immunogenic interference of PRP-T and DTwP combination Vaccines, a randomized, double-blind, controlled study was conducted in Belgium. A total of 168 healthy infants received, at 3, 4 and 5 months of age, DTwP Vaccine mixed just prior to injection either with PRP-T Vaccine (group A, DTwP//PRP-T, N =85) or with placebo (group B, DTwP//Placebo, N =83). At the age of 14 months, children of both groups were randomized to receive either a dose of DTwP//PRP-T Vaccine (subgroups A1 and B1) or a dose of Hib polysaccharide (PRP) Vaccine (subgroups A2 and B2). Those children in subgroups A1 and B1 had an additional serum sample taken at the age of 5 years (at the time of a DT booster). The immune response to Hib polysaccharide at the age of 4, 5 and 6 months confirmed the excellent immunogenicity profile of PRP-T in infants. In addition, the vigorous anamnestic response (i.e. a 20-fold increase of GMT) to a booster dose of the plain capsular polysaccharide (PRP) reflected the efficient Hib-priming induced by the combined DTwP//PRP-T Vaccine. Reconstitution of PRP-T with DTwP did not affect the immune response to diphtheria toxoid or pertussis agglutinins. Nevertheless, at almost any time point during the five-year follow-up, the tetanus antitoxin GMT values were significantly lower in the DTwP//PRP-T group (A and A1) than in the DTwP//Placebo group (B and B1). Despite the suppressive effect on GMT values, intergroup differences in rates of seroprotection were never significant, except after doses 2 and 3 for which there were lower percentages of children in group A with antitoxin titers >0.05 IU/mL and >1.0 IU/mL. In the group primed with the combined DTwP//PRP-T Vaccine, (1) a DT booster dose at the age of 5 years provoked a 150-fold increase in tetanus antitoxin GMT, (2) a high tetanus antitoxin GMT value was attained (GMT=19.3 IU/mL) and (3) all children in this group had tetanus antitoxin titers >1.0 IU/mL, so it may be concluded that all these children will still be protected against tetanus until at least the age of the next recommended booster dose (i.e. the age of 15 years). No differences in the occurrence of adverse events were observed between the groups who received the DTwP//PRP-T Vaccine or the DTwP//Placebo Vaccine, both Vaccines being associated with events customarily attributable to DTwP (data not shown). Our results indicate (1) that the combination Vaccine, DTwP//PRP-T, represents a safe and effective alternative for the existing uncombined Vaccines and (2) that the long-term effect of interference between the components of future combination Vaccines should be studied with subsequent booster doses, followed by the evaluation of persistence of antibodies over several years.
-
Priming effect, immunogenicity and safety of an Haemophilus influenzae type b-tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-acellular pertussis (DTaP) combination Vaccine administered to infants in Belgium and Turkey.
Vaccine, 1999Co-Authors: K Hoppenbrouwers, G Kanra, M Roelants, M Ceyhan, C Vandermeulen, K Yurdakök, T Silier, M Dupuy, T Pehlivan, E OzmertAbstract:To evaluate the priming effect, immunogenicity and safety of an Haemophilus influenzae type b (Hib) tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-acellular (two component) pertussis (DTaP) combination Vaccine, a randomized, comparative study was conducted in two centers, one in Belgium and one in Turkey. A total of 410 healthy infants, 160 in Belgium and 250 in Turkey, randomly received DTaP and PRP-T Vaccines in one of three fashions. One group (N = 138) received DTaP and PRP-T Vaccines reconstituted immediately prior to injection at 3, 4 and 5 months of age, and are referred to as the combined, short schedule group (Co-S). A second group (N = 135) received DTaP + PRP-T simultaneously but injected at different sites according to the same schedule, and are referred to as the associated, short schedule group (As-S). The third group (N = 137) also received DTaP + PRP-T at separate sites, but at 2, 4 and 6 months, and are referred to as the associated, long schedule group (As-L). The As-L group allowed for serological bridging with a Senegalese two-component pertussis Vaccine efficacy trial, using the same batch of DTaP Vaccine. Children of both short-schedule groups (Co-S and As-S) received, at the age of 12-14 months, a booster dose of DTaP Vaccine associated with unconjugated PRP Vaccine. Mixing of the Vaccines did not affect the immune response to the antigens included in the DTaP Vaccine. The immune response to Hib capsular polysaccharide, however, was significantly lower after combined administration (Co-S group) than after associated (As-S group) administration (P < 0.0001), with a similar trend among both countries (GMTs, 1.78 microg/ml and 6.19 microg/ml in Belgium, and 5.02 microg/ml and 11.67 microg/ml in Turkey). Booster vaccination with the unconjugated PRP induced a vigorous and similar anamnestic response in both groups. Belgian infants showed a significantly lower immune response to all antigens than Turkish infants (P < or = 0.001 for all antigens), with a similar trend among each study group. In all groups, the incidence of adverse events was lower than that usually reported after DTwP(whole-cell) Vaccine. Higher rates of systemic reactions were observed in the Belgian population, possibly due to differences in reporting practice. Our results indicate (1) that the combination Vaccine, DTaP//PRP-T, represents an important improvement over the existing uncombined Vaccines; (2) that immunogenicity studies should include at least one booster injection to evaluate priming effects by combined Vaccines; and (3) that it is feasible and valuable to co-randomize combination Vaccine studies in sufficiently different geographical areas and child populations.
-
priming effect immunogenicity and safety of an haemophilus influenzae type b tetanus toxoid conjugate PRP t and diphtheria tetanus acellular pertussis dtap combination Vaccine administered to infants in belgium and turkey
Vaccine, 1999Co-Authors: K Hoppenbrouwers, G Kanra, M Roelants, M Ceyhan, C Vandermeulen, K Yurdakök, T Silier, M Dupuy, T Pehlivan, E OzmertAbstract:Abstract To evaluate the priming effect, immunogenicity and safety of an Haemophilus influenzae type b (Hib) tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-acellular (two component) pertussis (DTaP) combination Vaccine, a randomized, comparative study was conducted in two centers, one in Belgium and one in Turkey. A total of 410 healthy infants, 160 in Belgium and 250 in Turkey, randomly received DTaP and PRP-T Vaccines in one of three fashions. One group ( N =138) received DTaP and PRP-T Vaccines reconstituted immediately prior to injection at 3, 4 and 5 months of age, and are referred to as the combined, short schedule group (Co-S). A second group ( N =135) received DTaP+PRP-T simultaneously but injected at different sites according to the same schedule, and are referred to as the associated, short schedule group (As-S). The third group ( N =137) also received DTaP+PRP-T at separate sites, but at 2, 4 and 6 months, and are referred to as the associated, long schedule group (As-L). The As-L group allowed for serological bridging with a Senegalese two-component pertussis Vaccine efficacy trial, using the same batch of DTaP Vaccine. Children of both short-schedule groups (Co-S and As-S) received, at the age of 12–14 months, a booster dose of DTaP Vaccine associated with unconjugated PRP Vaccine. Mixing of the Vaccines did not affect the immune response to the antigens included in the DTaP Vaccine. The immune response to Hib capsular polysaccharide, however, was significantly lower after combined administration (Co-S group) than after associated (As-S group) administration ( P μ g/ml and 6.19 μ g/ml in Belgium, and 5.02 μ g/ml and 11.67 μ g/ml in Turkey). Booster vaccination with the unconjugated PRP induced a vigorous and similar anamnestic response in both groups. Belgian infants showed a significantly lower immune response to all antigens than Turkish infants ( P ⩽0.001 for all antigens), with a similar trend among each study group. In all groups, the incidence of adverse events was lower than that usually reported after DTwP(whole-cell) Vaccine. Higher rates of systemic reactions were observed in the Belgian population, possibly due to differences in reporting practice. Our results indicate (1) that the combination Vaccine, DTaPPRP-T, represents an important improvement over the existing uncombined Vaccines; (2) that immunogenicity studies should include at least one booster injection to evaluate priming effects by combined Vaccines; and (3) that it is feasible and valuable to co-randomize combination Vaccine studies in sufficiently different geographical areas and child populations.
C Vandermeulen - One of the best experts on this subject based on the ideXlab platform.
-
The effect of reconstitution of an Haemophilus influenzae type b-tentanus toxoid conjugate (PRP-T) Vaccine on the immune responses to a diphtheria-tetanus-whole cell pertussis (DTwP) Vaccine: a five-year follow-up.
Vaccine, 1999Co-Authors: K Hoppenbrouwers, M Roelants, C Vandermeulen, C Ethevenaux, J Knops, J DesmyterAbstract:Controversial results have been obtained from previous studies on the combined administration of Haemophilus influenzae type b-tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-whole-cell pertussis (DTwP) combination Vaccines, with regard to possible reciprocal interference between the constituent antigens. To document the priming effect and possible long-term immunogenic interference of PRP-T and DTwP combination Vaccines, a randomized, double-blind, controlled study was conducted in Belgium. A total of 168 healthy infants received, at 3, 4 and 5 months of age, DTwP Vaccine mixed just prior to injection either with PRP-T Vaccine (group A, DTwP//PRP-T, N = 85) or with placebo (group B, DTwP//Placebo, N = 83). At the age of 14 months, children of both groups were randomized to receive either a dose of DTwP//PRP-T Vaccine (subgroups A1 and B1) or a dose of Hib polysaccharide (PRP) Vaccine (subgroups A2 and B2). Those children in subgroups A1 and B1 had an additional serum sample taken at the age of 5 years (at the time of a DT booster). The immune response to Hib polysaccharide at the age of 4, 5 and 6 months confirmed the excellent immunogenicity profile of PRP-T in infants. In addition, the vigorous anamnestic response (i.e. a 20-fold increase of GMT) to a booster dose of the plain capsular polysaccharide (PRP) reflected the efficient Hib-priming induced by the combined DTwP//PRP-T Vaccine. Reconstitution of PRP-T with DTwP did not affect the immune response to diphtheria toxoid or pertussis agglutinins. Nevertheless, at almost any time point during the five-year follow-up, the tetanus antitoxin GMT values were significantly lower in the DTwP//PRP-T group (A and A1) than in the DTwP//Placebo group (B and B1). Despite the suppressive effect on GMT values, intergroup differences in rates of seroprotection were never significant, except after doses 2 and 3 for which there were lower percentages of children in group A with antitoxin titers > 0.05 IU/mL and > 1.0 IU/mL. In the group primed with the combined DTwP//PRP-T Vaccine, (1) a DT booster dose at the age of 5 years provoked a 150-fold increase in tetanus antitoxin GMT, (2) a high tetanus antitoxin GMT value was attained (GMT = 19.3 IU/mL) and (3) all children in this group had tetanus antitoxin titers > 1.0 IU/mL, so it may be concluded that all these children will still be protected against tetanus until at least the age of the next recommended booster dose (i.e. the age of 15 years). No differences in the occurrence of adverse events were observed between the groups who received the DTwP//PRP-T Vaccine or the DTwP//Placebo Vaccine, both Vaccines being associated with events customarily attributable to DTwP (data not shown). Our results indicate (1) that the combination Vaccine, DTwP//PRP-T, represents a safe and effective alternative for the existing uncombined Vaccines and (2) that the long-term effect of interference between the components of future combination Vaccines should be studied with subsequent booster doses, followed by the evaluation of persistence of antibodies over several years.
-
The effect of reconstitution of an Haemophilus influenzae type b-tetanus toxoid conjugate (PRP-T) Vaccine on the immune responses to a diphtheria–tetanus-whole cell pertussis (DTwP) Vaccine: a five-year follow-up
Vaccine, 1999Co-Authors: K Hoppenbrouwers, M Roelants, C Vandermeulen, C Ethevenaux, J Knops, J DesmyterAbstract:Abstract Controversial results have been obtained from previous studies on the combined administration of Haemophilus influenzae type b-tetanus toxoid conjugate (PRP-T) and diphtheria–tetanus-whole-cell pertussis (DTwP) combination Vaccines, with regard to possible reciprocal interference between the constituent antigens. To document the priming effect and possible long-term immunogenic interference of PRP-T and DTwP combination Vaccines, a randomized, double-blind, controlled study was conducted in Belgium. A total of 168 healthy infants received, at 3, 4 and 5 months of age, DTwP Vaccine mixed just prior to injection either with PRP-T Vaccine (group A, DTwP//PRP-T, N =85) or with placebo (group B, DTwP//Placebo, N =83). At the age of 14 months, children of both groups were randomized to receive either a dose of DTwP//PRP-T Vaccine (subgroups A1 and B1) or a dose of Hib polysaccharide (PRP) Vaccine (subgroups A2 and B2). Those children in subgroups A1 and B1 had an additional serum sample taken at the age of 5 years (at the time of a DT booster). The immune response to Hib polysaccharide at the age of 4, 5 and 6 months confirmed the excellent immunogenicity profile of PRP-T in infants. In addition, the vigorous anamnestic response (i.e. a 20-fold increase of GMT) to a booster dose of the plain capsular polysaccharide (PRP) reflected the efficient Hib-priming induced by the combined DTwP//PRP-T Vaccine. Reconstitution of PRP-T with DTwP did not affect the immune response to diphtheria toxoid or pertussis agglutinins. Nevertheless, at almost any time point during the five-year follow-up, the tetanus antitoxin GMT values were significantly lower in the DTwP//PRP-T group (A and A1) than in the DTwP//Placebo group (B and B1). Despite the suppressive effect on GMT values, intergroup differences in rates of seroprotection were never significant, except after doses 2 and 3 for which there were lower percentages of children in group A with antitoxin titers >0.05 IU/mL and >1.0 IU/mL. In the group primed with the combined DTwP//PRP-T Vaccine, (1) a DT booster dose at the age of 5 years provoked a 150-fold increase in tetanus antitoxin GMT, (2) a high tetanus antitoxin GMT value was attained (GMT=19.3 IU/mL) and (3) all children in this group had tetanus antitoxin titers >1.0 IU/mL, so it may be concluded that all these children will still be protected against tetanus until at least the age of the next recommended booster dose (i.e. the age of 15 years). No differences in the occurrence of adverse events were observed between the groups who received the DTwP//PRP-T Vaccine or the DTwP//Placebo Vaccine, both Vaccines being associated with events customarily attributable to DTwP (data not shown). Our results indicate (1) that the combination Vaccine, DTwP//PRP-T, represents a safe and effective alternative for the existing uncombined Vaccines and (2) that the long-term effect of interference between the components of future combination Vaccines should be studied with subsequent booster doses, followed by the evaluation of persistence of antibodies over several years.
-
Priming effect, immunogenicity and safety of an Haemophilus influenzae type b-tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-acellular pertussis (DTaP) combination Vaccine administered to infants in Belgium and Turkey.
Vaccine, 1999Co-Authors: K Hoppenbrouwers, G Kanra, M Roelants, M Ceyhan, C Vandermeulen, K Yurdakök, T Silier, M Dupuy, T Pehlivan, E OzmertAbstract:To evaluate the priming effect, immunogenicity and safety of an Haemophilus influenzae type b (Hib) tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-acellular (two component) pertussis (DTaP) combination Vaccine, a randomized, comparative study was conducted in two centers, one in Belgium and one in Turkey. A total of 410 healthy infants, 160 in Belgium and 250 in Turkey, randomly received DTaP and PRP-T Vaccines in one of three fashions. One group (N = 138) received DTaP and PRP-T Vaccines reconstituted immediately prior to injection at 3, 4 and 5 months of age, and are referred to as the combined, short schedule group (Co-S). A second group (N = 135) received DTaP + PRP-T simultaneously but injected at different sites according to the same schedule, and are referred to as the associated, short schedule group (As-S). The third group (N = 137) also received DTaP + PRP-T at separate sites, but at 2, 4 and 6 months, and are referred to as the associated, long schedule group (As-L). The As-L group allowed for serological bridging with a Senegalese two-component pertussis Vaccine efficacy trial, using the same batch of DTaP Vaccine. Children of both short-schedule groups (Co-S and As-S) received, at the age of 12-14 months, a booster dose of DTaP Vaccine associated with unconjugated PRP Vaccine. Mixing of the Vaccines did not affect the immune response to the antigens included in the DTaP Vaccine. The immune response to Hib capsular polysaccharide, however, was significantly lower after combined administration (Co-S group) than after associated (As-S group) administration (P < 0.0001), with a similar trend among both countries (GMTs, 1.78 microg/ml and 6.19 microg/ml in Belgium, and 5.02 microg/ml and 11.67 microg/ml in Turkey). Booster vaccination with the unconjugated PRP induced a vigorous and similar anamnestic response in both groups. Belgian infants showed a significantly lower immune response to all antigens than Turkish infants (P < or = 0.001 for all antigens), with a similar trend among each study group. In all groups, the incidence of adverse events was lower than that usually reported after DTwP(whole-cell) Vaccine. Higher rates of systemic reactions were observed in the Belgian population, possibly due to differences in reporting practice. Our results indicate (1) that the combination Vaccine, DTaP//PRP-T, represents an important improvement over the existing uncombined Vaccines; (2) that immunogenicity studies should include at least one booster injection to evaluate priming effects by combined Vaccines; and (3) that it is feasible and valuable to co-randomize combination Vaccine studies in sufficiently different geographical areas and child populations.
-
priming effect immunogenicity and safety of an haemophilus influenzae type b tetanus toxoid conjugate PRP t and diphtheria tetanus acellular pertussis dtap combination Vaccine administered to infants in belgium and turkey
Vaccine, 1999Co-Authors: K Hoppenbrouwers, G Kanra, M Roelants, M Ceyhan, C Vandermeulen, K Yurdakök, T Silier, M Dupuy, T Pehlivan, E OzmertAbstract:Abstract To evaluate the priming effect, immunogenicity and safety of an Haemophilus influenzae type b (Hib) tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-acellular (two component) pertussis (DTaP) combination Vaccine, a randomized, comparative study was conducted in two centers, one in Belgium and one in Turkey. A total of 410 healthy infants, 160 in Belgium and 250 in Turkey, randomly received DTaP and PRP-T Vaccines in one of three fashions. One group ( N =138) received DTaP and PRP-T Vaccines reconstituted immediately prior to injection at 3, 4 and 5 months of age, and are referred to as the combined, short schedule group (Co-S). A second group ( N =135) received DTaP+PRP-T simultaneously but injected at different sites according to the same schedule, and are referred to as the associated, short schedule group (As-S). The third group ( N =137) also received DTaP+PRP-T at separate sites, but at 2, 4 and 6 months, and are referred to as the associated, long schedule group (As-L). The As-L group allowed for serological bridging with a Senegalese two-component pertussis Vaccine efficacy trial, using the same batch of DTaP Vaccine. Children of both short-schedule groups (Co-S and As-S) received, at the age of 12–14 months, a booster dose of DTaP Vaccine associated with unconjugated PRP Vaccine. Mixing of the Vaccines did not affect the immune response to the antigens included in the DTaP Vaccine. The immune response to Hib capsular polysaccharide, however, was significantly lower after combined administration (Co-S group) than after associated (As-S group) administration ( P μ g/ml and 6.19 μ g/ml in Belgium, and 5.02 μ g/ml and 11.67 μ g/ml in Turkey). Booster vaccination with the unconjugated PRP induced a vigorous and similar anamnestic response in both groups. Belgian infants showed a significantly lower immune response to all antigens than Turkish infants ( P ⩽0.001 for all antigens), with a similar trend among each study group. In all groups, the incidence of adverse events was lower than that usually reported after DTwP(whole-cell) Vaccine. Higher rates of systemic reactions were observed in the Belgian population, possibly due to differences in reporting practice. Our results indicate (1) that the combination Vaccine, DTaPPRP-T, represents an important improvement over the existing uncombined Vaccines; (2) that immunogenicity studies should include at least one booster injection to evaluate priming effects by combined Vaccines; and (3) that it is feasible and valuable to co-randomize combination Vaccine studies in sufficiently different geographical areas and child populations.
M Roelants - One of the best experts on this subject based on the ideXlab platform.
-
The effect of reconstitution of an Haemophilus influenzae type b-tentanus toxoid conjugate (PRP-T) Vaccine on the immune responses to a diphtheria-tetanus-whole cell pertussis (DTwP) Vaccine: a five-year follow-up.
Vaccine, 1999Co-Authors: K Hoppenbrouwers, M Roelants, C Vandermeulen, C Ethevenaux, J Knops, J DesmyterAbstract:Controversial results have been obtained from previous studies on the combined administration of Haemophilus influenzae type b-tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-whole-cell pertussis (DTwP) combination Vaccines, with regard to possible reciprocal interference between the constituent antigens. To document the priming effect and possible long-term immunogenic interference of PRP-T and DTwP combination Vaccines, a randomized, double-blind, controlled study was conducted in Belgium. A total of 168 healthy infants received, at 3, 4 and 5 months of age, DTwP Vaccine mixed just prior to injection either with PRP-T Vaccine (group A, DTwP//PRP-T, N = 85) or with placebo (group B, DTwP//Placebo, N = 83). At the age of 14 months, children of both groups were randomized to receive either a dose of DTwP//PRP-T Vaccine (subgroups A1 and B1) or a dose of Hib polysaccharide (PRP) Vaccine (subgroups A2 and B2). Those children in subgroups A1 and B1 had an additional serum sample taken at the age of 5 years (at the time of a DT booster). The immune response to Hib polysaccharide at the age of 4, 5 and 6 months confirmed the excellent immunogenicity profile of PRP-T in infants. In addition, the vigorous anamnestic response (i.e. a 20-fold increase of GMT) to a booster dose of the plain capsular polysaccharide (PRP) reflected the efficient Hib-priming induced by the combined DTwP//PRP-T Vaccine. Reconstitution of PRP-T with DTwP did not affect the immune response to diphtheria toxoid or pertussis agglutinins. Nevertheless, at almost any time point during the five-year follow-up, the tetanus antitoxin GMT values were significantly lower in the DTwP//PRP-T group (A and A1) than in the DTwP//Placebo group (B and B1). Despite the suppressive effect on GMT values, intergroup differences in rates of seroprotection were never significant, except after doses 2 and 3 for which there were lower percentages of children in group A with antitoxin titers > 0.05 IU/mL and > 1.0 IU/mL. In the group primed with the combined DTwP//PRP-T Vaccine, (1) a DT booster dose at the age of 5 years provoked a 150-fold increase in tetanus antitoxin GMT, (2) a high tetanus antitoxin GMT value was attained (GMT = 19.3 IU/mL) and (3) all children in this group had tetanus antitoxin titers > 1.0 IU/mL, so it may be concluded that all these children will still be protected against tetanus until at least the age of the next recommended booster dose (i.e. the age of 15 years). No differences in the occurrence of adverse events were observed between the groups who received the DTwP//PRP-T Vaccine or the DTwP//Placebo Vaccine, both Vaccines being associated with events customarily attributable to DTwP (data not shown). Our results indicate (1) that the combination Vaccine, DTwP//PRP-T, represents a safe and effective alternative for the existing uncombined Vaccines and (2) that the long-term effect of interference between the components of future combination Vaccines should be studied with subsequent booster doses, followed by the evaluation of persistence of antibodies over several years.
-
The effect of reconstitution of an Haemophilus influenzae type b-tetanus toxoid conjugate (PRP-T) Vaccine on the immune responses to a diphtheria–tetanus-whole cell pertussis (DTwP) Vaccine: a five-year follow-up
Vaccine, 1999Co-Authors: K Hoppenbrouwers, M Roelants, C Vandermeulen, C Ethevenaux, J Knops, J DesmyterAbstract:Abstract Controversial results have been obtained from previous studies on the combined administration of Haemophilus influenzae type b-tetanus toxoid conjugate (PRP-T) and diphtheria–tetanus-whole-cell pertussis (DTwP) combination Vaccines, with regard to possible reciprocal interference between the constituent antigens. To document the priming effect and possible long-term immunogenic interference of PRP-T and DTwP combination Vaccines, a randomized, double-blind, controlled study was conducted in Belgium. A total of 168 healthy infants received, at 3, 4 and 5 months of age, DTwP Vaccine mixed just prior to injection either with PRP-T Vaccine (group A, DTwP//PRP-T, N =85) or with placebo (group B, DTwP//Placebo, N =83). At the age of 14 months, children of both groups were randomized to receive either a dose of DTwP//PRP-T Vaccine (subgroups A1 and B1) or a dose of Hib polysaccharide (PRP) Vaccine (subgroups A2 and B2). Those children in subgroups A1 and B1 had an additional serum sample taken at the age of 5 years (at the time of a DT booster). The immune response to Hib polysaccharide at the age of 4, 5 and 6 months confirmed the excellent immunogenicity profile of PRP-T in infants. In addition, the vigorous anamnestic response (i.e. a 20-fold increase of GMT) to a booster dose of the plain capsular polysaccharide (PRP) reflected the efficient Hib-priming induced by the combined DTwP//PRP-T Vaccine. Reconstitution of PRP-T with DTwP did not affect the immune response to diphtheria toxoid or pertussis agglutinins. Nevertheless, at almost any time point during the five-year follow-up, the tetanus antitoxin GMT values were significantly lower in the DTwP//PRP-T group (A and A1) than in the DTwP//Placebo group (B and B1). Despite the suppressive effect on GMT values, intergroup differences in rates of seroprotection were never significant, except after doses 2 and 3 for which there were lower percentages of children in group A with antitoxin titers >0.05 IU/mL and >1.0 IU/mL. In the group primed with the combined DTwP//PRP-T Vaccine, (1) a DT booster dose at the age of 5 years provoked a 150-fold increase in tetanus antitoxin GMT, (2) a high tetanus antitoxin GMT value was attained (GMT=19.3 IU/mL) and (3) all children in this group had tetanus antitoxin titers >1.0 IU/mL, so it may be concluded that all these children will still be protected against tetanus until at least the age of the next recommended booster dose (i.e. the age of 15 years). No differences in the occurrence of adverse events were observed between the groups who received the DTwP//PRP-T Vaccine or the DTwP//Placebo Vaccine, both Vaccines being associated with events customarily attributable to DTwP (data not shown). Our results indicate (1) that the combination Vaccine, DTwP//PRP-T, represents a safe and effective alternative for the existing uncombined Vaccines and (2) that the long-term effect of interference between the components of future combination Vaccines should be studied with subsequent booster doses, followed by the evaluation of persistence of antibodies over several years.
-
Priming effect, immunogenicity and safety of an Haemophilus influenzae type b-tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-acellular pertussis (DTaP) combination Vaccine administered to infants in Belgium and Turkey.
Vaccine, 1999Co-Authors: K Hoppenbrouwers, G Kanra, M Roelants, M Ceyhan, C Vandermeulen, K Yurdakök, T Silier, M Dupuy, T Pehlivan, E OzmertAbstract:To evaluate the priming effect, immunogenicity and safety of an Haemophilus influenzae type b (Hib) tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-acellular (two component) pertussis (DTaP) combination Vaccine, a randomized, comparative study was conducted in two centers, one in Belgium and one in Turkey. A total of 410 healthy infants, 160 in Belgium and 250 in Turkey, randomly received DTaP and PRP-T Vaccines in one of three fashions. One group (N = 138) received DTaP and PRP-T Vaccines reconstituted immediately prior to injection at 3, 4 and 5 months of age, and are referred to as the combined, short schedule group (Co-S). A second group (N = 135) received DTaP + PRP-T simultaneously but injected at different sites according to the same schedule, and are referred to as the associated, short schedule group (As-S). The third group (N = 137) also received DTaP + PRP-T at separate sites, but at 2, 4 and 6 months, and are referred to as the associated, long schedule group (As-L). The As-L group allowed for serological bridging with a Senegalese two-component pertussis Vaccine efficacy trial, using the same batch of DTaP Vaccine. Children of both short-schedule groups (Co-S and As-S) received, at the age of 12-14 months, a booster dose of DTaP Vaccine associated with unconjugated PRP Vaccine. Mixing of the Vaccines did not affect the immune response to the antigens included in the DTaP Vaccine. The immune response to Hib capsular polysaccharide, however, was significantly lower after combined administration (Co-S group) than after associated (As-S group) administration (P < 0.0001), with a similar trend among both countries (GMTs, 1.78 microg/ml and 6.19 microg/ml in Belgium, and 5.02 microg/ml and 11.67 microg/ml in Turkey). Booster vaccination with the unconjugated PRP induced a vigorous and similar anamnestic response in both groups. Belgian infants showed a significantly lower immune response to all antigens than Turkish infants (P < or = 0.001 for all antigens), with a similar trend among each study group. In all groups, the incidence of adverse events was lower than that usually reported after DTwP(whole-cell) Vaccine. Higher rates of systemic reactions were observed in the Belgian population, possibly due to differences in reporting practice. Our results indicate (1) that the combination Vaccine, DTaP//PRP-T, represents an important improvement over the existing uncombined Vaccines; (2) that immunogenicity studies should include at least one booster injection to evaluate priming effects by combined Vaccines; and (3) that it is feasible and valuable to co-randomize combination Vaccine studies in sufficiently different geographical areas and child populations.
-
priming effect immunogenicity and safety of an haemophilus influenzae type b tetanus toxoid conjugate PRP t and diphtheria tetanus acellular pertussis dtap combination Vaccine administered to infants in belgium and turkey
Vaccine, 1999Co-Authors: K Hoppenbrouwers, G Kanra, M Roelants, M Ceyhan, C Vandermeulen, K Yurdakök, T Silier, M Dupuy, T Pehlivan, E OzmertAbstract:Abstract To evaluate the priming effect, immunogenicity and safety of an Haemophilus influenzae type b (Hib) tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-acellular (two component) pertussis (DTaP) combination Vaccine, a randomized, comparative study was conducted in two centers, one in Belgium and one in Turkey. A total of 410 healthy infants, 160 in Belgium and 250 in Turkey, randomly received DTaP and PRP-T Vaccines in one of three fashions. One group ( N =138) received DTaP and PRP-T Vaccines reconstituted immediately prior to injection at 3, 4 and 5 months of age, and are referred to as the combined, short schedule group (Co-S). A second group ( N =135) received DTaP+PRP-T simultaneously but injected at different sites according to the same schedule, and are referred to as the associated, short schedule group (As-S). The third group ( N =137) also received DTaP+PRP-T at separate sites, but at 2, 4 and 6 months, and are referred to as the associated, long schedule group (As-L). The As-L group allowed for serological bridging with a Senegalese two-component pertussis Vaccine efficacy trial, using the same batch of DTaP Vaccine. Children of both short-schedule groups (Co-S and As-S) received, at the age of 12–14 months, a booster dose of DTaP Vaccine associated with unconjugated PRP Vaccine. Mixing of the Vaccines did not affect the immune response to the antigens included in the DTaP Vaccine. The immune response to Hib capsular polysaccharide, however, was significantly lower after combined administration (Co-S group) than after associated (As-S group) administration ( P μ g/ml and 6.19 μ g/ml in Belgium, and 5.02 μ g/ml and 11.67 μ g/ml in Turkey). Booster vaccination with the unconjugated PRP induced a vigorous and similar anamnestic response in both groups. Belgian infants showed a significantly lower immune response to all antigens than Turkish infants ( P ⩽0.001 for all antigens), with a similar trend among each study group. In all groups, the incidence of adverse events was lower than that usually reported after DTwP(whole-cell) Vaccine. Higher rates of systemic reactions were observed in the Belgian population, possibly due to differences in reporting practice. Our results indicate (1) that the combination Vaccine, DTaPPRP-T, represents an important improvement over the existing uncombined Vaccines; (2) that immunogenicity studies should include at least one booster injection to evaluate priming effects by combined Vaccines; and (3) that it is feasible and valuable to co-randomize combination Vaccine studies in sufficiently different geographical areas and child populations.
E Ozmert - One of the best experts on this subject based on the ideXlab platform.
-
Priming effect, immunogenicity and safety of an Haemophilus influenzae type b-tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-acellular pertussis (DTaP) combination Vaccine administered to infants in Belgium and Turkey.
Vaccine, 1999Co-Authors: K Hoppenbrouwers, G Kanra, M Roelants, M Ceyhan, C Vandermeulen, K Yurdakök, T Silier, M Dupuy, T Pehlivan, E OzmertAbstract:To evaluate the priming effect, immunogenicity and safety of an Haemophilus influenzae type b (Hib) tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-acellular (two component) pertussis (DTaP) combination Vaccine, a randomized, comparative study was conducted in two centers, one in Belgium and one in Turkey. A total of 410 healthy infants, 160 in Belgium and 250 in Turkey, randomly received DTaP and PRP-T Vaccines in one of three fashions. One group (N = 138) received DTaP and PRP-T Vaccines reconstituted immediately prior to injection at 3, 4 and 5 months of age, and are referred to as the combined, short schedule group (Co-S). A second group (N = 135) received DTaP + PRP-T simultaneously but injected at different sites according to the same schedule, and are referred to as the associated, short schedule group (As-S). The third group (N = 137) also received DTaP + PRP-T at separate sites, but at 2, 4 and 6 months, and are referred to as the associated, long schedule group (As-L). The As-L group allowed for serological bridging with a Senegalese two-component pertussis Vaccine efficacy trial, using the same batch of DTaP Vaccine. Children of both short-schedule groups (Co-S and As-S) received, at the age of 12-14 months, a booster dose of DTaP Vaccine associated with unconjugated PRP Vaccine. Mixing of the Vaccines did not affect the immune response to the antigens included in the DTaP Vaccine. The immune response to Hib capsular polysaccharide, however, was significantly lower after combined administration (Co-S group) than after associated (As-S group) administration (P < 0.0001), with a similar trend among both countries (GMTs, 1.78 microg/ml and 6.19 microg/ml in Belgium, and 5.02 microg/ml and 11.67 microg/ml in Turkey). Booster vaccination with the unconjugated PRP induced a vigorous and similar anamnestic response in both groups. Belgian infants showed a significantly lower immune response to all antigens than Turkish infants (P < or = 0.001 for all antigens), with a similar trend among each study group. In all groups, the incidence of adverse events was lower than that usually reported after DTwP(whole-cell) Vaccine. Higher rates of systemic reactions were observed in the Belgian population, possibly due to differences in reporting practice. Our results indicate (1) that the combination Vaccine, DTaP//PRP-T, represents an important improvement over the existing uncombined Vaccines; (2) that immunogenicity studies should include at least one booster injection to evaluate priming effects by combined Vaccines; and (3) that it is feasible and valuable to co-randomize combination Vaccine studies in sufficiently different geographical areas and child populations.
-
priming effect immunogenicity and safety of an haemophilus influenzae type b tetanus toxoid conjugate PRP t and diphtheria tetanus acellular pertussis dtap combination Vaccine administered to infants in belgium and turkey
Vaccine, 1999Co-Authors: K Hoppenbrouwers, G Kanra, M Roelants, M Ceyhan, C Vandermeulen, K Yurdakök, T Silier, M Dupuy, T Pehlivan, E OzmertAbstract:Abstract To evaluate the priming effect, immunogenicity and safety of an Haemophilus influenzae type b (Hib) tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-acellular (two component) pertussis (DTaP) combination Vaccine, a randomized, comparative study was conducted in two centers, one in Belgium and one in Turkey. A total of 410 healthy infants, 160 in Belgium and 250 in Turkey, randomly received DTaP and PRP-T Vaccines in one of three fashions. One group ( N =138) received DTaP and PRP-T Vaccines reconstituted immediately prior to injection at 3, 4 and 5 months of age, and are referred to as the combined, short schedule group (Co-S). A second group ( N =135) received DTaP+PRP-T simultaneously but injected at different sites according to the same schedule, and are referred to as the associated, short schedule group (As-S). The third group ( N =137) also received DTaP+PRP-T at separate sites, but at 2, 4 and 6 months, and are referred to as the associated, long schedule group (As-L). The As-L group allowed for serological bridging with a Senegalese two-component pertussis Vaccine efficacy trial, using the same batch of DTaP Vaccine. Children of both short-schedule groups (Co-S and As-S) received, at the age of 12–14 months, a booster dose of DTaP Vaccine associated with unconjugated PRP Vaccine. Mixing of the Vaccines did not affect the immune response to the antigens included in the DTaP Vaccine. The immune response to Hib capsular polysaccharide, however, was significantly lower after combined administration (Co-S group) than after associated (As-S group) administration ( P μ g/ml and 6.19 μ g/ml in Belgium, and 5.02 μ g/ml and 11.67 μ g/ml in Turkey). Booster vaccination with the unconjugated PRP induced a vigorous and similar anamnestic response in both groups. Belgian infants showed a significantly lower immune response to all antigens than Turkish infants ( P ⩽0.001 for all antigens), with a similar trend among each study group. In all groups, the incidence of adverse events was lower than that usually reported after DTwP(whole-cell) Vaccine. Higher rates of systemic reactions were observed in the Belgian population, possibly due to differences in reporting practice. Our results indicate (1) that the combination Vaccine, DTaPPRP-T, represents an important improvement over the existing uncombined Vaccines; (2) that immunogenicity studies should include at least one booster injection to evaluate priming effects by combined Vaccines; and (3) that it is feasible and valuable to co-randomize combination Vaccine studies in sufficiently different geographical areas and child populations.
J Desmyter - One of the best experts on this subject based on the ideXlab platform.
-
The effect of reconstitution of an Haemophilus influenzae type b-tentanus toxoid conjugate (PRP-T) Vaccine on the immune responses to a diphtheria-tetanus-whole cell pertussis (DTwP) Vaccine: a five-year follow-up.
Vaccine, 1999Co-Authors: K Hoppenbrouwers, M Roelants, C Vandermeulen, C Ethevenaux, J Knops, J DesmyterAbstract:Controversial results have been obtained from previous studies on the combined administration of Haemophilus influenzae type b-tetanus toxoid conjugate (PRP-T) and diphtheria-tetanus-whole-cell pertussis (DTwP) combination Vaccines, with regard to possible reciprocal interference between the constituent antigens. To document the priming effect and possible long-term immunogenic interference of PRP-T and DTwP combination Vaccines, a randomized, double-blind, controlled study was conducted in Belgium. A total of 168 healthy infants received, at 3, 4 and 5 months of age, DTwP Vaccine mixed just prior to injection either with PRP-T Vaccine (group A, DTwP//PRP-T, N = 85) or with placebo (group B, DTwP//Placebo, N = 83). At the age of 14 months, children of both groups were randomized to receive either a dose of DTwP//PRP-T Vaccine (subgroups A1 and B1) or a dose of Hib polysaccharide (PRP) Vaccine (subgroups A2 and B2). Those children in subgroups A1 and B1 had an additional serum sample taken at the age of 5 years (at the time of a DT booster). The immune response to Hib polysaccharide at the age of 4, 5 and 6 months confirmed the excellent immunogenicity profile of PRP-T in infants. In addition, the vigorous anamnestic response (i.e. a 20-fold increase of GMT) to a booster dose of the plain capsular polysaccharide (PRP) reflected the efficient Hib-priming induced by the combined DTwP//PRP-T Vaccine. Reconstitution of PRP-T with DTwP did not affect the immune response to diphtheria toxoid or pertussis agglutinins. Nevertheless, at almost any time point during the five-year follow-up, the tetanus antitoxin GMT values were significantly lower in the DTwP//PRP-T group (A and A1) than in the DTwP//Placebo group (B and B1). Despite the suppressive effect on GMT values, intergroup differences in rates of seroprotection were never significant, except after doses 2 and 3 for which there were lower percentages of children in group A with antitoxin titers > 0.05 IU/mL and > 1.0 IU/mL. In the group primed with the combined DTwP//PRP-T Vaccine, (1) a DT booster dose at the age of 5 years provoked a 150-fold increase in tetanus antitoxin GMT, (2) a high tetanus antitoxin GMT value was attained (GMT = 19.3 IU/mL) and (3) all children in this group had tetanus antitoxin titers > 1.0 IU/mL, so it may be concluded that all these children will still be protected against tetanus until at least the age of the next recommended booster dose (i.e. the age of 15 years). No differences in the occurrence of adverse events were observed between the groups who received the DTwP//PRP-T Vaccine or the DTwP//Placebo Vaccine, both Vaccines being associated with events customarily attributable to DTwP (data not shown). Our results indicate (1) that the combination Vaccine, DTwP//PRP-T, represents a safe and effective alternative for the existing uncombined Vaccines and (2) that the long-term effect of interference between the components of future combination Vaccines should be studied with subsequent booster doses, followed by the evaluation of persistence of antibodies over several years.
-
The effect of reconstitution of an Haemophilus influenzae type b-tetanus toxoid conjugate (PRP-T) Vaccine on the immune responses to a diphtheria–tetanus-whole cell pertussis (DTwP) Vaccine: a five-year follow-up
Vaccine, 1999Co-Authors: K Hoppenbrouwers, M Roelants, C Vandermeulen, C Ethevenaux, J Knops, J DesmyterAbstract:Abstract Controversial results have been obtained from previous studies on the combined administration of Haemophilus influenzae type b-tetanus toxoid conjugate (PRP-T) and diphtheria–tetanus-whole-cell pertussis (DTwP) combination Vaccines, with regard to possible reciprocal interference between the constituent antigens. To document the priming effect and possible long-term immunogenic interference of PRP-T and DTwP combination Vaccines, a randomized, double-blind, controlled study was conducted in Belgium. A total of 168 healthy infants received, at 3, 4 and 5 months of age, DTwP Vaccine mixed just prior to injection either with PRP-T Vaccine (group A, DTwP//PRP-T, N =85) or with placebo (group B, DTwP//Placebo, N =83). At the age of 14 months, children of both groups were randomized to receive either a dose of DTwP//PRP-T Vaccine (subgroups A1 and B1) or a dose of Hib polysaccharide (PRP) Vaccine (subgroups A2 and B2). Those children in subgroups A1 and B1 had an additional serum sample taken at the age of 5 years (at the time of a DT booster). The immune response to Hib polysaccharide at the age of 4, 5 and 6 months confirmed the excellent immunogenicity profile of PRP-T in infants. In addition, the vigorous anamnestic response (i.e. a 20-fold increase of GMT) to a booster dose of the plain capsular polysaccharide (PRP) reflected the efficient Hib-priming induced by the combined DTwP//PRP-T Vaccine. Reconstitution of PRP-T with DTwP did not affect the immune response to diphtheria toxoid or pertussis agglutinins. Nevertheless, at almost any time point during the five-year follow-up, the tetanus antitoxin GMT values were significantly lower in the DTwP//PRP-T group (A and A1) than in the DTwP//Placebo group (B and B1). Despite the suppressive effect on GMT values, intergroup differences in rates of seroprotection were never significant, except after doses 2 and 3 for which there were lower percentages of children in group A with antitoxin titers >0.05 IU/mL and >1.0 IU/mL. In the group primed with the combined DTwP//PRP-T Vaccine, (1) a DT booster dose at the age of 5 years provoked a 150-fold increase in tetanus antitoxin GMT, (2) a high tetanus antitoxin GMT value was attained (GMT=19.3 IU/mL) and (3) all children in this group had tetanus antitoxin titers >1.0 IU/mL, so it may be concluded that all these children will still be protected against tetanus until at least the age of the next recommended booster dose (i.e. the age of 15 years). No differences in the occurrence of adverse events were observed between the groups who received the DTwP//PRP-T Vaccine or the DTwP//Placebo Vaccine, both Vaccines being associated with events customarily attributable to DTwP (data not shown). Our results indicate (1) that the combination Vaccine, DTwP//PRP-T, represents a safe and effective alternative for the existing uncombined Vaccines and (2) that the long-term effect of interference between the components of future combination Vaccines should be studied with subsequent booster doses, followed by the evaluation of persistence of antibodies over several years.
