RESUMO
Background: Data are needed to serve as evidence in planning the strengthening of pharmacovigilance in health programs administering drugs to populations. The present study was proposed to map the distribution of pharmacovigilance units in health programs, assess the availability of key resources, the implementation of key pharmacovigilance activities and identify needs of involved actors. Methods: It was a cross sectional descriptive study targeting all health programs of the Cameroon Ministry of Public Health administering drugs/vaccines to the population. Data were collected using semi structured questionnaire administered face to face to key persons in charge of drug safety monitoring or drug management in health programs. Results: Out of the 09 health programs involved in drug distribution, 07 consented to participate. Five out of them (71.4%) claimed to have existing pharmacovigilance units. Office space, computers, operating budget, data analysis software and a trained staff were available in 28.6%, 42.9%, 42.9%, 14.3%, 00.0%, and 42.9% of the health programs respectively. One of the 7 health programs (14.3%) declared conducting detection/notification of adverse events following exposure drugs, 2 (28.6%) conduct causality assessment and 3 (42.8%) conduct analysis of pharmacovigilance data. All health programs proposed to prioritize the allocation of budget and qualified personnel and the training of existing personnel as key interventions to improve drugs/vaccines safety monitoring in health programs. Conclusion: The study reports limited coverage of Cameroon health programs with activities leading to drugs and vaccine safety monitoring. Suggested actions have to be taken into account when attempting to improve the situation.
RESUMO
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.