Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7-8
pubmed:dateCreated
1999-5-27
pubmed:abstractText
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.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0264-410X
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
17
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
875-86
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
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.
pubmed:affiliation
Department of Youth Health Care, Katholieke Universiteit Leuven, Belgium.
pubmed:publicationType
Journal Article, Clinical Trial, Comparative Study, Randomized Controlled Trial, Multicenter Study