Comparison of adverse reactions to whole-virion and split-virion influenza vaccines in hospital personnel

OBJECTIVE: To compare the adverse effects, particularly generalized aching, of a trivalent, inactivated whole-virion vaccine (WVV) and split-virion vaccine (SVV) for influenza in hospital personnel. DESIGN: Recipient-blinded study; first-time vaccinees were randomly assigned to receive either of the vaccines from one manufacturer in the 1989-90 influenza season. Subjects were asked to complete a symptom questionnaire during the 48 hours after immunization. SETTING: Annual influenza program for staff of a tertiary care children9s hospital. PARTICIPANTS: Volunteers were sought among approximately 2200 members of the hospital staff. Of the 358 vaccinated for the first time, 333 (93%) returned the questionnaire. RESULTS: During the 48 hours after vaccination 13% of the SVV recipients reported generalized aching, as compared with 26% of the WVV recipients (p less than 0.01). Also, the SVV group reported fewer visible local reactions and more transient arm soreness, but the actual differences between the two groups were small. The occurrence of mild symptoms was equally common in the two groups (local reactions in at least 70% of cases, systemic reactions in at least 33%). In each group 1% of the subjects reported missing work because of the vaccination. CONCLUSIONS: The use of SVV reduces the rate of the most objectionable of the common adverse effects of influenza vaccination. Therefore, as with children, it might be more acceptable to health care workers than the current use of WVV.