• Adverse events;
  • fever;
  • influenza vaccine;
  • paediatrics;
  • safety


To evaluate the safety of CSL's split-virion inactivated trivalent 2009 Southern Hemisphere formulation influenza vaccine (TIV) in children.


We enrolled 1992 healthy children into three groups: Cohorts A, ≥6 months to <3 years; B, ≥3 years to <9 years; and C, ≥9 years to <18 years. Children received one or two doses of 0·25 ml (22·5 μg haemagglutinin) or 0·5 ml (45 μg) TIV, depending on age and prior vaccination history. We collected post-vaccination solicited adverse event (AE) data (days 0–6), including fever (temperature: ≥37·5°C axilla, ≥38·0°C oral), unsolicited AEs (days 0–29) and serious AEs (SAEs) and new-onset chronic illnesses (NOCIs; to day 180 after last vaccination).


At least one solicited AE was reported by 80%/78%/78% of children in Cohorts A, B and C, respectively. Systemic AEs were more common among Cohort A (72% of participants), and local AEs were more common among Cohort C (71% of participants). Fever was more common in younger cohorts, in influenza vaccine-naïve children (29% of Cohort A receiving their first dose), and following first compared with second doses. Severe fever following a first dose prevented 20 participants receiving their second scheduled vaccine dose. A 7-month-old participant had a single uncomplicated febrile convulsion on the day of vaccination.


Nearly 80% of subjects reported at least one solicited AE following immunization. Fever prevalence was highest in vaccine-naïve Cohort A participants, similar to other paediatric studies using CSL vaccine. Further research to understand fever-related AEs in children following CSL's TIV is recommended.