| Autor: |
Ateudjieu J; MA Sante, Yaoundé, Cameroon.; Department of Public Health, Faculty of Medicine and Pharmaceutical Sciences, University of Dschang, Cameroon.; Clinical Research Unit, Division of Health Operations Research, Ministry of Public Health, Cameroon., Sack DA; Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland., Nafack SS; MA Sante, Yaoundé, Cameroon., Xiao S; Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland., Tchio-Nighie KH; MA Sante, Yaoundé, Cameroon., Tchokomeni H; MA Sante, Yaoundé, Cameroon., Bita'a LB; MA Sante, Yaoundé, Cameroon., Nyibio PN; MA Sante, Yaoundé, Cameroon., Guenou E; MA Sante, Yaoundé, Cameroon., Mondung KM; MA Sante, Yaoundé, Cameroon., Dieumo FFK; MA Sante, Yaoundé, Cameroon., Ngome RM; Department of Bacteriology-Parasitology-Mycology Laboratory, Centre Pasteur of Cameroon (CPC), Yaoundé, Cameroon., Murt KN; Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland., Ram M; Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland., Ali M; Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland., Debes AK; Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland. |
| Abstrakt: |
The recommended schedule for killed oral cholera vaccine (OCV) is two doses, 2 weeks apart. However, during vaccine campaigns, the second round is often delayed by several months. Because more information is needed to document antibody responses when the second dose is delayed, we conducted an open-label, phase 2, noninferiority clinical trial of OCV. One hundred eighty-six participants were randomized into three dose-interval groups (DIGs) to receive the second dose 2 weeks, 6 months, or 11.5 months after the first dose. The DIGs were stratified into three age strata: 1 to 4, 5 to 14, and > 14 years. Inaba and Ogawa vibriocidal titers were assessed before and after vaccination. The primary analysis was geometric mean titer (GMT) 2 weeks after the second dose. Data for primary analysis was available from 147 participants (54, 44, and 49 participants from the three DIGs respectively). Relative to the 2-week interval, groups receiving a delayed second dose had significantly higher GMTs after the second dose. Two weeks after the second dose, Inaba GMTs were 55.1 190.3, and 289.8 and Ogawa GMTs were 70.4, 134.5, and 302.4 for the three DIGs respectively. The elevated titers were brief, returning to lower levels within 3 months. We conclude that when the second dose of killed oral cholera vaccine was given after 6 or 11.5 months, vibriocidal titers were higher than when given after the standard period of 2 weeks. This provides reassurance that a delayed second dose does not compromise, but rather enhances, the serological response to the vaccine. |
