Study participants are invited to receive the clinically recommended seasonal influenza and pneumococcal polysaccharide vaccines during the seasonal influenza vaccination season (September - December), mirroring routine care they would receive in the community. Information on age, gender and pre-existing health problems, together with blood and urine samples will be collected from CKD patients for comparison with healthy volunteers at the following timepoints: day of vaccination, day 7 and 28 and 6 months after vaccination.