Conference abstract
Effects of extended dose interval on the immune response to Oral Cholera Vaccine in Cameroon
Pan African Medical Journal - Conference Proceedings. 2023:18(24).03
Oct 2023.
doi: 10.11604/pamj-cp.2023.18.24.2071
Archived on: 03 Oct 2023
Contact the corresponding author
Keywords: Cholera, vaccination, clinical trial, administration interval
Oral presentation
Effects of extended dose interval on the immune response to Oral Cholera Vaccine in Cameroon
Jerome Ateudjieu1,2,3,&, Ketina Hirma Tchio-Nighie1,2, Collins Buh Nkum2, David Sack4
1Department of Public Health, Faculty of Medicine and Pharmaceutical Sciences, University of Dschang, Dschang, Cameroon, 2Department of Health Research, M.A. SANTE (Meilleur Accès aux Soins de Santé), Yaoundé, Cameroon, 3Division of Health Operations Research, Ministry of Public Health, Yaoundé, Cameroon, 4Johns Hopkins University, Baltimore, Etats-Unis
&Corresponding author
Introduction: the suddenness of the cholera outbreak and rapid dehydration of serious cases contribute to the high morbidity and mortality of cases. The limited availability of Oral Cholera Vaccine Doses (OCV) makes it difficult to be used in epidemic situations. This project aimed at assessing the equivalence of the immune response when the second OCV dose is given at 6 months and 11.5 months compared to the standard 2 weeks.
Methods: this was a randomized open-labeled phase 2 clinical trial targeting individuals aged > 1 year in the Soboum Health Area in Douala Cameroon, from 2018 to 2020. The participants were organized into three study groups. The first dose of OCV was received at day 0 for all the groups, while the second dose was received at day 14, 6 months, and 11.5 months for groups 1, 2, and 3 respectively. Blood samples were collected at defined intervals and the vibriocidal response was estimated.
Results: out of the 199 eligible participants, 186 were included in the study and randomly assigned to study group 1(62), group 2 (61), and 63 to study group 3. The vibriocidal geometric mean titer was significantly higher in group 2 and group 3 compared to group 1 estimated at similar intervals post-dose 2. The magnitude of vibriocidal antibody response 3 months after the second dose seems not to differ when extended to 6 months and 11.5 months for both Inaba and Ogawa Vibrio cholera serotypes. The same tendency was observed at 6 and 9 months when the second dose was extended to 6 months.
Conclusion: extending the delay of administration of the second dose to 6 months or 11.5 months showed a high immune response compared to 2 weeks. This study provides evidence that in situations of epidemics where there are limited vaccine doses, a one-round campaign can be conducted, and the second dose administered at a prolonged interval.
Effects of extended dose interval on the immune response to Oral Cholera Vaccine in Cameroon
Jerome Ateudjieu1,2,3,&, Ketina Hirma Tchio-Nighie1,2, Collins Buh Nkum2, David Sack4
1Department of Public Health, Faculty of Medicine and Pharmaceutical Sciences, University of Dschang, Dschang, Cameroon, 2Department of Health Research, M.A. SANTE (Meilleur Accès aux Soins de Santé), Yaoundé, Cameroon, 3Division of Health Operations Research, Ministry of Public Health, Yaoundé, Cameroon, 4Johns Hopkins University, Baltimore, Etats-Unis
&Corresponding author
Introduction: the suddenness of the cholera outbreak and rapid dehydration of serious cases contribute to the high morbidity and mortality of cases. The limited availability of Oral Cholera Vaccine Doses (OCV) makes it difficult to be used in epidemic situations. This project aimed at assessing the equivalence of the immune response when the second OCV dose is given at 6 months and 11.5 months compared to the standard 2 weeks.
Methods: this was a randomized open-labeled phase 2 clinical trial targeting individuals aged > 1 year in the Soboum Health Area in Douala Cameroon, from 2018 to 2020. The participants were organized into three study groups. The first dose of OCV was received at day 0 for all the groups, while the second dose was received at day 14, 6 months, and 11.5 months for groups 1, 2, and 3 respectively. Blood samples were collected at defined intervals and the vibriocidal response was estimated.
Results: out of the 199 eligible participants, 186 were included in the study and randomly assigned to study group 1(62), group 2 (61), and 63 to study group 3. The vibriocidal geometric mean titer was significantly higher in group 2 and group 3 compared to group 1 estimated at similar intervals post-dose 2. The magnitude of vibriocidal antibody response 3 months after the second dose seems not to differ when extended to 6 months and 11.5 months for both Inaba and Ogawa Vibrio cholera serotypes. The same tendency was observed at 6 and 9 months when the second dose was extended to 6 months.
Conclusion: extending the delay of administration of the second dose to 6 months or 11.5 months showed a high immune response compared to 2 weeks. This study provides evidence that in situations of epidemics where there are limited vaccine doses, a one-round campaign can be conducted, and the second dose administered at a prolonged interval.
