Flexibility of oral cholera vaccine dosing-a randomized controlled trial measuring immune responses following alternative vaccination schedules in a cholera hyper-endemic zone
A bivalent killed whole cell oral cholera vaccine has been found to be safe and efficacious for five years in the cholera endemic setting of Kolkata, India, when given in a two dose schedule, two weeks apart. A randomized controlled trial revealed that the immune response was not significantly incre...
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Published in | PLoS neglected tropical diseases Vol. 9; no. 3; p. e0003574 |
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Main Authors | , , , , , , , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
Public Library of Science
01.03.2015
Public Library of Science (PLoS) |
Subjects | |
Online Access | Get full text |
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Summary: | A bivalent killed whole cell oral cholera vaccine has been found to be safe and efficacious for five years in the cholera endemic setting of Kolkata, India, when given in a two dose schedule, two weeks apart. A randomized controlled trial revealed that the immune response was not significantly increased following the second dose compared to that after the first dose. We aimed to evaluate the impact of an extended four week dosing schedule on vibriocidal response.
In this double blind randomized controlled non-inferiority trial, 356 Indian, non-pregnant residents aged 1 year or older were randomized to receive two doses of oral cholera vaccine at 14 and 28 day intervals. We compared vibriocidal immune responses between these schedules. Among adults, no significant differences were noted when comparing the rates of seroconversion for V. cholerae O1 Inaba following two dose regimens administered at a 14 day interval (55%) vs the 28 day interval (58%). Similarly, no differences in seroconversion were demonstrated in children comparing the 14 (80%) and 28 day intervals (77%). Following 14 and 28 day dosing intervals, vibriocidal response rates against V. cholerae O1 Ogawa were 45% and 49% in adults and 73% and 72% in children respectively. Responses were lower for V. cholerae O139, but similar between dosing schedules for adults (20%, 20%) and children (28%, 20%).
Comparable immune responses and safety profiles between the two dosing schedules support the option for increased flexibility of current OCV dosing. Further operational research using a longer dosing regimen will provide answers to improve implementation and delivery of cholera vaccination in endemic and epidemic outbreak scenarios. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 MSD is an employee of Shantha Biotechnics. All other authors declare they have no conflicts of interest. This does not alter our adherence to all PLOS policies on sharing data and materials. Conceived and designed the experiments: SK MKB DS ALL JDC SND MA MSD TFW. Performed the experiments: AS JSY RKN. Analyzed the data: DRK BB SND SK BM TM. Contributed reagents/materials/analysis tools: JSY AS. Wrote the first draft of the paper: SK SND. Critically reviewed the data and finalized the manuscript: DS AMC JDC MA TFW. |
ISSN: | 1935-2735 1935-2727 1935-2735 |
DOI: | 10.1371/journal.pntd.0003574 |