Pneumonia is one of the most important causes of serious illness among children in The Gambia caused by a germ. There are roughly 90 different types of these pneumococcal bacteria and these can spread from person to person through close contact. It is likely that a new vaccine (Prevenar R) will soon be introduced into childhood immunization programme in The Gambia. This vaccine can work only on seven types but does not contain two forms of the germ that are important causes of invasive disease in The Gambia. In addition, there are concerns that the disease could re-emerge if children were infected with the other types of pneumococcal not covered in the original vaccine. We want to determine whether the introduction of this vaccine into a community will result in an increase in the carriage rate of these germs in the nose and throat without apparent disease and compare it to the germs in the nose and throat of children who did not receive this vaccine but a vaccine that prevent meningitis as a control. Swabs will be collected from the throats by a small stick with wool on the end one to three times a year. Some members of the household will contribute a small volume of blood and saliva before and after vaccination and subsequently at 3, 12 and 24 months after the completion of the first round of vaccination.

There is evidence that infection with intestinal helminths is associated with an increased relative risk of clinical malaria. A possible explanation for this is that intestinal helminth infections have the potential to bias antibody responses to malaria. Helminth infected individuals respond to malaria infection predominantly by the production of so called non-cytophilic antibodies that are not protective.||Comparatively little is known about the interaction of malaria and lymphatic filariasis or Onchocerciasis, mainly because definitive cure for these diseases is hard to achieve. Recently, studies carried out in malaria endemic areas have shown that treatment with doxycycline is effective against these pathogens, resulting in the killing of the adult worms.||Using serum samples from these studies we investigated if the clearance of the adult worms results in an altered antibody profile against malaria.||We found that the profiles of malaria specific antibodies were similar before and after treatment of filarial worms.||Importantly, the malaria-antibody profile observed in Ghanaian patients infected with filarial worms prior to treatment was similar to that seen in studies in the Gambia, where filarial infections are virtually absent. This suggests that infection with filarial worms may not affect the quality of the antibody response to malaria infection.

The Viral Diseases Programme has been conducting studies on pathogenesis and immunology of HIV-2 since 1995 and has recently started studies on HTLV-1 pathogenesis We are planning a number of studies to take advantage of the extraordinary resource of an HIV-2-infected community cohort with more than 15 years of follow-up in order to advance our understanding of HIV-2 pathogenesis and protective immunity. Recent studies in the Caio have indicated that there is a significant increase in mortality in HTLV-1-infected people, similar to that seen overall in the HIV-2. The reasons for the increased mortality rate associated with HTLV-1 infection are not clear. Studies have been proposed to investigate the potential for HTLV-1 to reduce the immune response to other pathogens and vaccines. We aim to link the serosurvey with the proposed rollout of ART in Guinea-Bissau (generic drugs provided by the Brazilian government) so that the participants will be able to link knowledge of their HIV status with access to ART where appropriate. We are coordinating with the Guinean National AIDS Control Programme to provide HIV testing and therapy if indicated.

Health outcomes in poor populations where infection and malnutrition still intersect, are influenced by a network of interacting genetic and environmental causal factors. Our Nutritional Genetics theme, linking in with the other research themes, employs genetic and epigenetic tools at a genome-wide scale to explore critical pathways that underpin or modulate nutritionally-mediated health and disease outcomes. We seek to understand the answers to the following questions: Does our genetic profile determine growth trajectories of children going up under a double burden of malnutrition and infectious diseases? Does maternal nutrition during early pregnancy mediate changes in gene regulation in their offspring? Does variation in genes regulating iron metabolism affect the response to infectious pathogens and/or susceptibility to anemia?

Malaria is a major cause of severe illness in children in The Gambia, and much of Africa. We would like to learn more about the immunity (protection in the body) to malaria and especially how long this lasts in young children. We would like to understand how important malaria parasites in the blood are for keeping immunity strong.In the study, 75 children will be selected by chance and given Fansidar to remove any parasites in the blood and 75 children not be given Fansidar at this time will as control. Subsequently, children will be visited at home weekly, for the next 14 weeks to record the health of the child. Every other week a finger prick blood sample will be taken to look for malaria parasites and measure immunity to understand the processes involved in protecting against malaria.