Safety and immunogenicity of Vi-DT conjugate vaccine among 6-23-month-old children: Phase II, randomized, dose-scheduling, observer-blind Study.
EClinicalMedicine
; 27: 100540, 2020 Oct.
Article
em En
| MEDLINE
| ID: mdl-33150320
ABSTRACT
BACKGROUND:
Typhoid causes significant mortality among young children in resource-limited settings. Conjugate typhoid vaccines could significantly reduce typhoid-related child deaths, but only one WHO-prequalified typhoid conjugate vaccine exists for young children. To address this gap, we investigated the safety, immunogenicity and dose-scheduling of Vi-DT typhoid conjugate vaccine among children aged 6-23 months.METHODS:
In this single center, observer blind, phase II trial, participants were randomly assigned (221) to receive one or two doses of Vi-DT or comparator vaccine. Anti-Vi IgG titer and geometric mean titers (GMT) were determined at 0, 4, 24 and 28 weeks. Data were analyzed using per-protocol and immunogenicity (a subset of intention-to-treat analysis) sets. The trial is registered with ClinicalTrials.gov (NCT03527355).FINDINGS:
Between April and July 2018, 285 children were randomized; 114 received one or two doses of Vi-DT while 57 received comparator. 277 completed the study follow-up per protocol; 112 and 110 from single- and two-dose Vi-DT schedules, respectively and 55 from the placebo group were included in the per protocol analysis. Safety profile is satisfactory. Thirteen serious adverse events were reported during the 28-week follow-up, none of which were related to Vi-DT. The seroconversion rate four weeks after the first dose was 100% (95% CI 98·3-100) in Vi-DT recipients and 7·0% (95% CI 2·8-16·7) in comparator recipients (p<0·0001). Similarly, the seroconversion rate 4 weeks after the second dose was 98·2% (95% CI 93· 6-99·5) and 21·8% (95% CI 13·0-34·4) among Vi-DT and comparator groups, respectively (p<0·0001). Anti-Vi IgG GMT was significantly higher in Vi-DT than in control group at all post-vaccination visits (p<0·0001).INTERPRETATION:
Both single and two doses of Vi-DT vaccine are safe, well tolerated, and immunogenic for infants and toddlers in a moderately endemic setting.
Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
2_ODS3
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6_ODS3_enfermedades_notrasmisibles
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7_ODS3_muertes_prevenibles_nacidos_ninos
Base de dados:
MEDLINE
Tipo de estudo:
Clinical_trials
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Guideline
Idioma:
En
Revista:
EClinicalMedicine
Ano de publicação:
2020
Tipo de documento:
Article