Vaccination Coverage and Level of Protection in Patients at Risk

1. Chronically ill children 1.1 What is the vaccination status for vaccines recommended by the Superior Health Council in pediatric chronically ill patients (2-16 years of age) who consult within the University hospital of Leuven? Patients with one of the following chronic conditions will be included: * Cystic fibrosis * Diabetes Mellitus type 1 * Allergic constitution * Congenital heart disease * Solid-organ transplantpatients * Immunodeficiency (congenital or acquired) * Cancer The vaccination coverage for the following vaccines will be determined: * Poliomyelitis * Diphtheria * Tetanus * Pertussis * Haemophilus influenzae type b * Hepatitis B * Measles-Mumps-Rubella * Pneumococci * Meningococcal serogroup C * Rotavirus * Diphtheria-Tetanus-Polio: booster (older than 7 years) * Human papillomavirus (girls of 13 yrs) * Seasonal flu (cystic fibrosis, immunodeficiencies) Timeliness of the vaccines given will also be determined. 1.2 Is the vaccination coverage of pediatric patients (2-16 years of age) comparable to the data on healthy children in 2012? 1.3 What are possible factors that influence coverage in this specific patient populations? 1.4 If the vaccination coverage is too low (below 90-95 percent), what are possbile solutions to increase the coverage rates within this group? 1.5. Determine antibody titers in this same population for the following vaccine-preventable infectious diseases: * Measles * Mumps * Rubella * Pertussis 1.6 Are antibody titers in this population similar to antibody titers measured in seroprevalence studies of healthy children in the same age group? 2. Adult patients at risk 2.1 What is the vaccinatiestatus for vaccines recommended by the Superior Health Council of adult patients at risk (over 18 years of age) who consult within the University hospital of Leuven? Patients with one or more of the following chronic conditions will be included in the study: * Chronic obstructive pulmonary disease (COPD) * Heart failure * Diabetes mellitus (Type 1 and 2) * Chronic kidney disease (stadium IV and V) * Solid organ Transplant patients * HIV * HSCT The vaccination coverage for the following vaccines will be determined: * Seasonal flu (yearly) * Diphtheria-tetanus (date of last dose) * Pneumococcus (1 dose/last dose before 5 years of age) * Pertussis (1 dose) * Hepatitis B (3 doses in specific risk groups) 2.2 Who immunizes these adult patients at risk? 2.3 What are possible risk factors who influences vaccination status in the adult population? 2.4 If the vaccination coverage is too low (below 90-95 percent), what are possible solutions to improve this coverage in these groups? 2.5 What are the antibody titers measured in the adult risk groups with a chronic condition for the following vaccine-preventable infectious diseases: * Diphtheria * Tetanus * Pertussis 2.6 Are antibody titers measured in this population comparable to those of healthy subjects as measured in previous seroprevalence studies?