View clinical trials related to Vaccine Response.
Filter by:Iron deficiency and anemia are health issues affecting mainly infants and women in developing countries. Iron deficiency in infancy can have long-lasting impact on cognitive and motor development of the child. Iron fortification has shown to be effective against anemia. However, in areas with a high burden of infectious diseases iron may increase the risk of unfavorable gut microbiota composition possibly influencing diarrhea prevalence. Therefore we want to assess the effects of home fortification of complementary food with two iron-containing micronutrient powders (MNPs) with and without the addition of a prebiotic (7.5 g of galactooligosaccharides as GOS-75) compared to a control on the composition of the gut microbiota of Kenyan infants. In addition, iron deficiency may iimpair adaptive immunity. Following Kenyan Minstry of Health guidelines, infants receive their first measles vaccine at 9 months. In this study we will use an MNP with a moderate iron dose of 5 mg, with 2.5 mg of Fe as NaFeEDTA and 2.5 mg of Fe as ferrous fumarate (+Fe). There will be 3 study groups MNP, MNP+Fe and MNP+Fe+GOS. The infants will be enrolled in the study at the age of 6-10 months and will consume a home-fortified maize porridge for four months. At baseline and endpoint (after 4 months of intervention), we will collect blood samples of the infants in order to assess anemia, iron status, and inflammation. In addition, we will assess the effect of iron supplementation on measles vaccine response. Fecal samples (from child and mother) will be collected at baseline, 3 weeks and at endpoint in order to evaluate the changes in gut microbiota and gut inflammation. During the intervention, in a sub-group of children who receive broad-spectrum antibiotics, we will compare how the three different interventions modify the effect of antibiotics on the infant gut microbiota. We will opportunistically select children that are enrolled in the study and who become ill, and who are prescribed antibiotics by the local health care team, according to the local standard of care in the study area. Five additional stool samples from these children will be collected (day 0 (before the first antibiotic dose), 5, 10, 20 and 40) to evaluate the changes in the gut microbiota and gut inflammation. Three years after the study end, we would like to collect a blood and stool sample from the children and examine the iron status and gut microbiome respectively.
Background: - Vaccines create resistance to disease. This study tests experimental human immunodeficiency virus (HIV) vaccines that use an adenovirus as a transporter. Transporters may help vaccines stimulate an immune response against HIV. This means the body works to fight infection. Researchers want to see if different ways of giving the vaccines cause different immune responses. They also want to see if the vaccines adenovirus is contagious. Adenoviruses cause cold symptoms or mild eye infections. Participants cannot get HIV from these vaccines. But they can get the adenovirus, so their entire household and intimate contacts must participate. Objective: - To test the safety of experimental HIV vaccines. Eligibility: - Healthy adults 18-49 years old. Design: - Participants will be screened with medical history, physical exam, and blood and urine tests. - Participants will receive the vaccine 3 times over 6 months. Each time, they will have a physical exam and blood and urine tests. Samples will be taken from their nose, rectum, and cervix. - Some participants will receive the vaccine by swallowing 11 capsules with water. Clinic staff will observe them for 1 hour. - Some participants will receive the vaccine swabbed in their throat. They will get dose 1 at the hospital and stay there for 1 week. They will have medical tests and nose swabs. Doses 2 and 3 will not require a hospital stay. - Participants will have 7 follow-up visits over 6 months, with a physical exam and blood tests. Samples will be taken from their nose, throat, and rectum. - Household and intimate contacts will have 4 clinic visits over 8 months, with a physical exam and blood tests.