Reactogenicity of two 2010 trivalent inactivated influenza vaccine formulations in adults

To assess the reactogenicity of two 2010 trivalent inactivated influenza vaccine (TIV) formulations among adults, including the formulation associated with febrile convulsions among children in Australia.

We retrospectively interviewed persons aged ≥18 years who received TIV between 11 March and 24 April 2010 at a large general practice in Perth. All 160 persons who received Influvac® (Solvay) and a random sample of 190 of 451 persons who received Fluvax® (CSL Biotherapies) were included in the assessment; 127 (79%) recipients of Influvac® and 156 (82%) of the Fluvax® recipients completed the interview.

Patient demographics, the presence of underlying medical conditions, prior influenza vaccination history, self-reported onset of local and/or systemic symptoms within 72 h following receipt of 2010 TIV, and use of anti-fever/pain medication following TIV vaccination were examined.

The mean age of the vaccinees was 54 years for both the Fluvax® and Influvac® brand cohorts and there was no significant difference between the cohorts with regard to gender or the presence of underlying medical conditions. In bivariate analyses, reported swelling (18% vs 7%, p=0.009), muscle pain (12% vs 3%, p=0.014) and use of anti-fever/pain medication after TIV vaccination (12% vs 2%, p=0.008) were each significantly more common for patients who received Fluvax® compared to those who received Influvac®. In multivariate analyses simultaneously controlling for age, gender, receipt of seasonal influenza vaccine prior to 2010 and receipt of 2009 H1N1 pandemic vaccine, vaccination with Fluvax® TIV was a significant independent predictor of muscle pain and/or swelling (OR=3.3, 95% CI 1.5-7.4 p=0.004). No significant differences in the proportion of patients reporting systemic reactions were observed.

In this setting, 2010 Fluvax® was associated with a greater likelihood of local reactions among adults, compared to 2010 Influvac® TIV.