Is it safe to give flu vaccinations to patients with an impaired immune response, such as those with diabetes? The evidence was both sparse and inconclusive, say researchers from Imperial College London. But their 7-year study of 124,503 patients with type 2 diabetes suggests “substantial benefits.”
The study covered 4 periods in each cohort year: preinfluenza, influenza season, postinfluenza, and summer. The outcome measures were hospital admissions for acute myocardial infarction (MI), stroke, pneumonia, influenza, and heart failure as well as all-cause death.
During the study, there were 5,142 admissions for acute MI; 4,515 for stroke; 14,154 for pneumonia or influenza; 12,915 for heart failure; and 21,070 deaths.
Vaccine recipients were older and generally more ill; they had more coexisting conditions and were taking more medications than nonrecipients. However, vaccination was associated with significant reductions in all the outcomes during the flu season. After adjusting for residual confounding, the researchers found 19% lower rates of admissions for acute MI, 30% for stroke, 22% for heart failure, and 15% for pneumonia or influenza. The mortality rate for patients was 24% lower than that of nonrecipients.
That was during flu season, but vaccination also was associated with significantly fewer events during the pre- and postinfluenza seasons for all outcomes except for acute MI and pneumonia/influenza in the preinfluenza period.
Concerns about the benefits of influenza vaccination in older adults and patients with chronic illnesses affect the acceptance and uptake of vaccination, the researchers note. But their findings, they add, “underline the importance of influenza vaccination as part of comprehensive secondary prevention in this high-risk population.”
Source:
Vamos EP, Pape UJ, Curcin V, et al. CMAJ. 2016;188(14):E342-E351.
