Use of influenza and pneumococcal vaccines in people with diabetes.

p roviders are not convinced of the threat of c e rtain infectious illnesses or the likelihood of benefit from vaccination. Altern a t i v e l y, immunization of individuals with diabetes may be one of the many clinical pro c e s s e s of care that has been shown to be deficient for this group of patients (7‐10). Initially for practical reasons and later for ethical reasons, there have been few p l a c e b o - c o n t rolled studies designed to demonstrate the efficacy of influenza and pneumococcal immunization specifically in individuals with diabetes. In addition, there a re few clinical studies that have examined the benefit of glycemic control, antibiotics, antiviral agents, and other nonvaccine meas u res in preventing and controlling infection. Current vaccine recommendations for people with diabetes are based on historical o b s e rvations in studies from population g roups that have included only a minority of patients with diabetes. What is the evidence that people with diabetes benefit f rom these immunizations? For the purpose of this re v i e w, we will examine the impact of two vaccine-preventable illnesses: influenza and pneumococcal infection. We will first examine the evidence re g a rding the immune re s p o n s e to viral and bacterial illness in people with diabetes. We will also review the evidence for the risks of infection in diabetes as it relates to antibody response, cell-mediated i m m u n i t y, leukocyte function, colonization rates, epidemiologic evidence for infection, immune response to immunization, and e fficacy of vaccination. We will then systematically review the clinical re p o rts of infection, vaccine immunogenicity, and vaccine effectiveness for influenza and pneumococcus in people with diabetes. F i n a l l y, we will review general vaccine implementation strategies. Because most studies re p o rting patient c o h o rts and outcomes give limited and variable information about patients with diabetes, we felt that combining re s e a rch re s u l t s (a meta-analysis) would not be valid. In addition to our concerns about this heterog e n e i t y, confounders such as age and underlying card i o p u l m o n a ry disease make risk assessment of diabetes by itself diff i c u l t . T h e re f o re, we have elected to provide a narrative re v i e w. Primary articles were identified f rom a Medline literature search without time restriction, using the key words immunization, vaccination, influenza, pneumococcus, and diabetes. Additional sourc e s w e re then identified from the re f e re n c e s listed from these primary sources. Searc h e s w e re perf o rmed using the last 2 years of C u rrent Contents. Further information was also obtained from contacts with the prim a ry authors of published art i c l e s .