There are about 68 clinical studies being (or have been) conducted in Guinea-Bissau. The country of the clinical trial is determined by the location of where the clinical research is being studied. Most studies are often held in multiple locations & countries.
Two studies from Asia have suggested a beneficial effect of vitamin A supplementation given at birth. Hypotheses: Vitamin A supplementation administered at birth together with BCG vaccination is associated with a 30% reduction in infant mortality and morbidity during the first year of life in normal birth weight children in an African setting.
Vitamin A supplementation reduces all-cause mortality. It is therefore given with oral polio vaccine in national campaigns. However, it is not clear which dose is optimal. The two studies that have investigated the impact of different doses of vitamin A have both found that a smaller dose was better than a large dose. We therefore investigated if a smaller dose given with oral polio vaccine gives equal or better effect.
Few data exist on long-term persistence of measles antibodies after vaccination of West African infants. The data that do exist indicate that the antibody titres decline very rapidly. Our data would be the first to describe the persistence of measles antibodies after two doses of measles vaccine, and the study would allow us to identify unprotected children and offer them revaccination. Since persistence of measles antibodies is of crucial importance to measles control, the study will contribute significantly to the existing knowledge and might have important implications for future eradication programmes.
The specific aims are to examine in Guinea-Bissau: - whether the standard titre Schwarz (SW) or standard-titre Edmonston-Zagreb (EZ) measles vaccine will be the best vaccine strain for use in a routine one-dose measles vaccination schedule and a two-dose measles vaccination schedule in terms of antibody response, protection against measles and child survival, and - whether the standard-titre Edmonston-Zagreb (EZ) vaccine will be suitable for use in a very early two-dose schedule vaccinating at 4½ and 9 months of age
OBJECTIVES - General: To investigate the immunological background for the non-specific effects of diphtheria-tetanus-pertussis (DTP) and measles vaccines on child mortality - Specific: Examine the cytokine responses and possible association with morbidity in a study of DTP vaccinated children who will be randomised to receive a measles vaccine or no vaccine at 4½ months of age. (All children will receive a measles vaccine at 9 months of age)
Objective It is the objective to test whether the use of prophylactic antibiotics in measles infection will reduce the incidence of post-measles pneumonia and/or admissions to hospital with 50%. The possible impact on other complications of severe measles will also be measured.
The World Health Organization (WHO) currently recommends BCG vaccination at birth in developing countries. Pre-term infants should be vaccinated when they reach the chronological age of 40 weeks. Due to difficulties in establishing the correct gestational age, the vaccination policy for BCG in many developing countries is defined by birth weight rather than by gestational maturity. In the study area, low birth weight (LBW) infants (< 2500 g) are not supposed to be vaccinated at birth; instead the mother is asked to return for vaccination when the child has gained sufficient weight. BCG has marked immune stimulatory effects in both animal and human studies and observational studies suggest that BCG is associated with a non-specific reduction in mortality in areas with high infant and child mortality. The specific objective of the study is to examine the effect of early vaccination of LBW children for adverse events, purified protein derivative of tuberculin (PPD) reaction, scar size, morbidity, and mortality in a randomised prospective study of BCG vaccination at birth versus later (according to policy) among children 19 months of age in Guinea-Bissau. The hypothesis is that BCG vaccination of low birth weight (LBW) children at birth reduces infant mortality of this high-risk group by 25%.
Children participating in a study evaluating the efficacy of chloroquine and amodiaquine for the treatment of malaria will, if getting malaria during follow-up, be re-treated with sulfadoxine-pyrimethamine (SP) in accordance with the recommendations of the National Malaria Programme. To compare the actual efficacy of SP with that in 1995 - 1996 we, the investigators of the Bandim Health Project, will visit these children once a week for 5 weeks. A finger prick blood sample will be collected for a malaria test. Children with malaria during follow-up will be treated according to the guidelines of the Bandim Health Centre.
This study will evaluate the efficacy of the treatment recommended by the National Malaria Programme in Guinea-Bissau as compared to a higher dose of chloroquine and to another anti-malarial drug, amodiaquine. The genetic basis of the parasites for developing resistance will be examined. Children coming to Bandim Health Centre with symptoms of malaria and a positive malaria test will be included. The children will be visited and malaria films will be obtained weekly until day 35. In case of a reappearance of parasites the children will be re-treated with sulfadoxine/pyrimethamine.
BCG vaccine is given at or shortly after birth in many developing countries to prevent tuberculosis. In Guinea Bissau, it has been shown that its protective effect against death is greater than would be expected from its effect against tuberculosis. This observation suggests that BCG may enhance the ability of the immune system of young children to make a protective response to other infections, including malaria. There is some evidence to support this hypothesis as BCG protects against malaria in experimental animals. Because BCG is a recommended vaccine, a randomised controlled trial of BCG at birth would not be ethically justifiable. However, it is not known whether re-vaccination with BCG in the second year of life might provide some added benefit and a large study to determine this is under way in Guinea Bissau. This study examined the effect of re-vaccination with BCG on the incidence of clinical malaria. If re-vaccination with BCG at 19 months of age is found to protect against malaria this would support the hypothesis that one of the ways that BCG at birth provides protection to young children is through an effect on malaria.