Among people with diabetes, influenza hospitalizations decreased for those who received the influenza vaccine in both the current and prior influenza seasons, according to a study published in Clinical Infectious Diseases.
Previous studies have demonstrated that the antibody response to influenza vaccination in people with diabetes is similar to that of healthy adults. The influenza vaccine effect in people with diabetes patients has also been evaluated in several studies, based on non-laboratory-confirmed clinical endpoints. However, the effect of influenza vaccination in preventing hospital admissions with laboratory-confirmed influenza over several seasons among diabetic patients remains unclear and inconclusive. Therefore, this study estimated the average effect of influenza vaccination status in preventing laboratory-confirmed hospitalization in diabetic patients over 6 influenza seasons.
The primary analysis evaluated the influenza vaccine effect over the course of 6 seasons (2013-2014 to 2018-2019) in the prevention of hospitalization with laboratory-confirmed influenza in people with diabetic. Cases included people with diabetes hospitalized for influenza-like illness and confirmed for influenza via reverse-transcription polymerase-chain-reaction. Controls included people with diabetes admitted for an influenza-like illness who tested negative for any influenza virus. The status of influenza vaccine in the current and previous 5 seasons was obtained from the regional vaccination register, and only vaccines received ³14 days before the onset of illness were considered.
In total, data from 1670 people with diabetes hospitalized during the 6 influenza seasons were included in the study. Results indicated that influenza vaccination of people with diabetes reduced the risk of influenza-related hospitalization. Overall, 569 (34%) patients had confirmed influenza, while 1101 patients were test-negative controls. Among both case and control patients, 58% and 68% were vaccinated in the current season, with 71% and 82% vaccinated in any of the 5 prior seasons, respectively.
When compared with unvaccinated patients in the current and prior seasons, the average effect of vaccination in preventing influenza hospitalization was 46% (95% CI, 28%-59%) for the current season and 44% (95% CI, 20%-61%) in prior seasons; this suggested that vaccination in prior seasons maintained a notable protective effect. Additionally, among the 34% of people with diabetes with confirmed influenza, current-season vaccination reduced the probability of hospitalization (adjusted odds ratio 0.35). The influenza vaccine effect estimated for vaccinations in the current seasons were higher in women with diabetes compared with men (58% vs 39%; (P interaction =.271) and in participants aged 9 to 64 years than in those 65 years or older (58% vs 40%; P interaction =.340); however, there was no statistical significance. Furthermore, a similar influenza vaccine effect was observed in older or chronic non-diabetic patients.
“Influenza vaccination reduces the risk of laboratory-confirmed influenza hospitalizations among people with diabetes,” the researchers concluded. “When…vaccination fails to prevent influenza disease in [people with diabetes], it can still reduce the probability of hospitalizations. Our results reinforce the recommendations of annual vaccination for influenza in patients with diabetes.”
Martinez-Baz I, Navascués A, Portillo ME, Casado I, Fresán U, Ezpeleta C, Castilla J. Effect of influenza vaccination in preventing laboratory-confirmed influenza hospitalization in patients with diabetes mellitus [published online May 15, 2020]. Clin Infect Dis. doi:10.1093/cid/ciaa564/5837528