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.
Prenatal maternal micronutrient supplementation has been suggested as a means to reduce the proportion of low birth weight babies in low-income countries. The effects of prenatal multi-micronutrient supplements on birth weight and perinatal mortality were studied in a randomised controlled trial among 2100 pregnant women in Guinea-Bissau. Women up to 37 weeks pregnant were individually randomised to daily supplements until delivery of A) Iron + folic acid or multi-micronutrients in B) One or C) Two recommended dietary allowances. Secondary outcomes were infant growth and maternal haemoglobin eight weeks after delivery.
The general objectives of the proposed research work are: A1) to reduce childhood mortality in developing countries through better control of measles infection by finding the best immunization strategy, and A2) to investigate the hypothesis that standard titre measles immunization is associated with non targeted beneficial effects on childhood morbidity and mortality in developing countries. The measurable, specific objectives of the present proposal are: B1) to examine whether a two-dose strategy for measles immunization at 6 and 9 months of age can reduce measles incidence by 50% through better coverage or improved seroconversion, and B2) to examine whether a two-dose strategy for measles immunization at 6 and 9 months of age can reduce childhood mortality by 20% through better coverage, better protection against measles or non targeted beneficial effects, and B3) to determine the magnitude and duration of non-measles related changes in morbidity patterns after standard titre measles immunization, in particular to test whether measles immunization is associated with a 15% reduction in the risk of diarrhoea, and B4) to determine non-measles related immunological changes among recipients of measles vaccine in order to establish possible pathways for the non targeted effects of standard titre measles immunization.
We previously compared the effect on mortality of the half dose and the full dose currently recommended by WHO. Unexpectedly, the low dose was clearly better for girls, but not for boys. The girls' response might have depended on the last vaccine received before the OPV and VAS campaign. We believe that these findings call for confirmation. In connection with a new campaign, we will examine whether half the dose or the full dose has a more beneficial effect on mortality and morbidity in girls, and furthermore address the potential effect modification by the last vaccine received before the supplementation.
Vitamin A supplementation (VAS) is important for the immune system and may interact with different childhood vaccinations. We have hypothesized that the improved survival after VAS may depend on vitamin A amplifying the non-specific immune modulation induced by vaccinations. In the present study we used information collected in connection with a national vitamin A campaign in Guinea-Bissau during which different doses of VAS was provided together with missing doses of DTP, OPV, and measles vaccines. We aimed to study the potential interactions between VAS and vaccine type.
In the present study the investigators wish to address the effects of different doses of vitamin A supplementation in low and normal birth weight infants. 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 both normal and low birth weight infants. - A lower dose of vitamin A may be even more beneficial than a high dose.
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)