According to an article published by Healio, survey data showed that patients aged 65 years and older who received a trivalent flu vaccine experienced more side effects than those who received the standard-dose vaccine. The increase in side effects did not impact those patients’ general health, Healio reports.

The researchers conducted a survey on elderly patients who used walk-in influenza vaccine clinics in the Minneapolis VA Health Care System from Oct. 27 to Oct. 29, 2015 (trivalent, n = 547; standard dose, n = 541).

Researchers wrote that among trivalent recipients, 37% reported a local or systemic side effect, compared with 22% of patients who received a standard-dose vaccine (P < .001). Most side effects were considered mild to moderate. Seven (1.3%) patients who received a trivalent vaccine reported severe side effects, as did three (0.6%) of recipients of standard-dose vaccine (P = .034).