Short and long-term safety of the 2009 AS03-adjuvanted pandemic vaccine

PLoS One. 2012;7(7):e38563. doi: 10.1371/journal.pone.0038563. Epub 2012 Jul 3.


Background: This study assessed the short and the long term safety of the 2009 AS03 adjuvanted monovalent pandemic vaccine through an active web-based electronic surveillance. We compared its safety profile to that of the seasonal trivalent inactivated influenza vaccine (TIV) for 2010-2011.

Methodology/principal findings: Health care workers (HCW) vaccinated in 2009 with the pandemic vaccine (Arepanrix ® from GSK) or HCW vaccinated in 2010 with the 2010-2011 TIV were invited to participate in a web-based active surveillance of vaccine safety. They completed two surveys the day-8 survey covered the first 7 days post-vaccination and the day-29 survey covered events occurring 8 to 28 days after vaccination. Those who reported a problem were called by a nurse to obtain details. The main outcome was the occurrence of a new health problem or the worsening of an existing health condition that resulted in a medical consultation or work absenteeism. For the pandemic vaccine, a six-month follow-up for the occurrence of serious adverse events (SAE) was conducted. Among the 6242 HCW who received the pandemic vaccine, 440 (7%) reported 468 events compared to 328 of the 7645 HCW (4.3%) who reported 339 events after the seasonal vaccine. The 2009 pandemic vaccine was associated with significantly more local reactions than the 2010-2011 seasonal vaccine (1% vs. 0.03%, p<0.001). Paresthesia was reported by 7 HCW (0.1%) after the pandemic vaccine but by none after the seasonal vaccine. For the pandemic vaccine, no clustering of SAE was found in the 6 month follow-up.

Conclusion: The 2009 pandemic vaccine seems to have a good safety profile, similar to the 2010-2011 TIV, with the exception of local reactions. This surveillance was adequately powered to identify AE associated with an excess risk ≥1 per 1000 vaccinations but is insufficient to detect rare AE.

Trial registration: NCT01289418, NCT01318876.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic
  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Female
  • Health Personnel
  • Humans
  • Influenza A Virus, H1N1 Subtype / immunology*
  • Influenza Vaccines / adverse effects*
  • Male
  • Middle Aged
  • Pandemics
  • Paresthesia / chemically induced


  • Adjuvants, Immunologic
  • Influenza Vaccines
  • arepanrix

Associated data