We are trying to understand how proteins called antibodies and the cells that make them work to protect against Salmonella infections. This should help improve vaccines against Salmonella and other bacteria since nearly all vaccines work via antibody. Salmonella infections can have deadly consequences killing hundreds of thousands around the world yearly. In some cases if Salmonella is found in an infant’s blood then that child has a near 25% chance of dying. Salmonella travels through the blood to infect and grow in many sites such as the liver or spleen. Yet the body is not defenceless against this spread because antibodies can bind Salmonella and lead to its killing. But to be effective the antibody needs to be present before the infection and this can be achieved by vaccination. Using a mouse model, since these complex events cannot be effectively mimicked in other systems, we have found that antibodies to some Salmonella proteins can prevent infection and may help us design an effective, safe vaccine. Since these Salmonella proteins and the cells that make the antibody have some unusual properties we hope that these studies may help us better understand how we fight bacteria and then use this information to design vaccines to other bacterial diseases.