Now showing 1 - 1 of 1
ItemOptimising immunisation in special risk groupsCrawford, Nigel William ( 2011)Special risk groups are those patients who are at higher risk of infections, including vaccine preventable diseases (VPD). This is because of their underlying disease and/or immunosuppressive therapies. These VPD and the associated morbidity can have a significant impact on both quality of life and long-term survival. The evidence base for special risk group immunisation guidelines requires further study and compliance with these guidelines in Australia is unknown. This thesis includes a number of complementary studies addressing strategies optimise the immunisation status of children and adolescents within special risk groups. It is important that special risk group patients are educated regarding their VPD risk and the ideal time to evaluate this is at diagnosis, prior to commencement of immunosuppressive therapy. The special risk vaccinology studies included clinical audits of the immunisation status of children and adolescents within four groups: inflammatory bowel disease (IBD), type 1 diabetes, preterm infants and paediatric oncology [Chapters 3-6]. This immunisation status was relative to current national guidelines and included complementary physicians surveys for two groups (neonatologists and paediatric oncologists). Two novel interventional vaccine immunogenicity studies in special risk groups were undertaken, using the 4-valent Human Papillomavirus (4vHPV) vaccine and a 10-valent pneumococcal conjugate vaccine (PCV10) [Chapters 7-8]. The final study was a randomised controlled trial of a postcard immunisation reminder in outpatients, aiming to utilise the Australian Childhood Immunisation Register (ACIR) and a reproducible intervention to optimise immunisation status in clinical practice [Chapter 9]. The clinical audits identified satisfactory immunisation coverage in special risk groups for routine scheduled vaccines, but low coverage for additional recommended immunisations such as influenza and pneumococcal vaccines. A follow-up audit in preterm infants showed a twofold increase is additional vaccine administration following education and practical strategies such as immunisation reminders in Child Health Records. The PCV10 vaccine produced a satisfactory immunogenicity response in children and adolescent during therapy for leukaemia (N=39), particularly in those who had received a primary PCV immunisation course prediagnosis. A minimum of 2 doses was required to produce an immunogenic response in those patients who were PCV naïve. The immunogenicity response to the 4vHPV vaccine in special risk groups (N=64) was robust and although reduced in those patients on biologic therapies, remained above HPV type specific sero-status antibody cut-offs. The postcard immunisation reminder did not produce a statistical difference in the outpatient’s immunisation status compared to controls. It did provide proof of principle in utilising the ACIR to link with hospital outpatient appointments and in the future may be linked to electronic ‘e’ health records. In conclusion, these complementary studies confirmed that a multimodal approach is required to optimise the immunisation of special risk groups. Improving the evidence base is important and long-term follow-up studies of serum immune persistence are required. These strategies require the support of patients, their families and treating health care professionals. Implementation of evidence-based immunisation strategies will optimise VPD protection of all special risk group patients.