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

Abstract

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: ClinicalTrials.gov NCT01289418, NCT01318876.

Conflict of interest statement

Competing Interests: The authors have read the journal’s policy and have the following conflicts: Gaston De Serres has received research grant from GSK, Sanofi Pasteur. Shelly McNeil has research grants from GSK, Pfizer, and Sanofi and participated in clinical trials for GSK, Sanofi, Pfizer, Merck, Novartis. She has received speaking fees/honoraria from Merck, GsK and Pfizer. Mélanie Benoît owned Janssen-ortho stocks and/or stock options and was an employee of Janssen-ortho (Johnson and Johnson) until 2009. Louis Valiquette has served on advisory boards for Abbott and Wyeth, and has received compensation to conduct clinical trials involving antibacterials from Genzyme, Wyeth, Merck, Pfizer, BioCryst, and Optimer. The other authors have declared that no competing interests exist. This does not alter the authors’ adherence to all the PLoS ONE policies on sharing data and materials.