In:
Infection and Immunity, American Society for Microbiology, Vol. 72, No. 11 ( 2004-11), p. 6586-6588
Abstract:
In a double-blind, randomized, and placebo-controlled previous trial, the efficacy of Vi- r EPA for typhoid fever in 2- to 5-year-olds was 89.0% for 46 months. Vi- r EPA contained 25 μg of Vi and induced a greater-than-eightfold rise in immunoglobulin G (IgG) anti-Vi in all of the vaccinees tested. In this investigation, we conducted a dosage-immunogenicity study of 5, 12.5, and 25 μg of Vi- r EPA in this age group. Two doses of Vi- r EPA were injected 6 weeks apart. Blood samples were taken before and at 10 weeks (4 weeks after the second injection) and 1 year later. All postimmunization geometric mean (GM) levels were higher than the preimmune levels ( P 〈 0.0001). At 10 weeks, the GM IgG anti-Vi level elicited by 25 μg (102 EU/ml) was higher than those elicited by 12.5 μg (74.7 EU/ml) and 5 μg (43 EU/ml) ( P 〈 0.004): all of the children had ≥3.52 EU/ml (estimated minimum protective level). One year later, the levels declined about sevenfold (13.3 and 11.3 versus 6.43 EU/ml, P 〈 0.0001) but remained significantly higher than the preimmune levels ( P 〈 0.0001), and 〉 96% of the children had a greater-than-eightfold rise. This study also confirmed the safety and consistent immunogenicity of the four lots of Vi- r EPA used in this and previous trials.
Type of Medium:
Online Resource
ISSN:
0019-9567
,
1098-5522
DOI:
10.1128/IAI.72.11.6586-6588.2004
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
2004
detail.hit.zdb_id:
1483247-1
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