Getting a flu shot might do more than just protect you from infection: a higher-dose flu vaccine may reduce older adults’ risk of developing Alzheimer’s disease over the next several years compared with a standard dose, according to a study published April 28, 2026, in Neurology.
More than 164,000 US insurance claims from those 65 and older (56% women) were examined by researchers. About 44,000 people received a standard-dose flu shot, compared to over 121,000 who received a high-dose shot. The researchers tracked diagnosis codes and prescriptions for Alzheimer’s drugs to determine the number of participants who developed Alzheimer’s over a three-year follow-up period following vaccination.
In the few years following immunization, the high-dose vaccine was associated with a marginally reduced incidence of Alzheimer’s; researchers calculated that the larger dose avoided one case of the illness for every 185 recipients. Additionally, the benefit seemed to be greater for women. Because the study was observational, it was only able to demonstrate the existence of a correlation rather than establish that higher-dose flu vaccines prevented Alzheimer’s. Also, the three-year follow-up period in this study is a short window for assessing the development of dementia, the study authors noted.
