Purpose: Previous study did not reveal any particular heptavalent pneumococcal conjugate vaccine (PCV7) related risk. However, french drugs agency (Afssaps) requested the continuation of its surveillance.
Methods: All serious PCV7-related adverse drug reactions spontaneously reported between October 1, 2004 and December 31, 2007 to the French pharmacovigilance centers or to Wyeth Pharmaceutical France were included. Vaccine failure was defined as an invasive pneumococcal infection due to vaccine serotype which occurs at least 15 days after the third dose of vaccine. Incidence rates were estimated according to the doses number except for vaccine failure estimated according to the vaccinated children number.
Results: During the 39-month follow-up period, 154 serious adverse drug reactions were spontaneously reported: convulsions (17%), fever (13%), hypotonia (10%), sudden death (7%) and thrombopenic purpura (6%). Evolution was recovery in 72% of cases. PCV7 was the only suspect medication in 28% of cases. The median age was 4 months (range 1-108), and the children's sex was male in 53%. The adverse drug reaction recurred after a subsequent injection in six cases. Among the 24 pneumococcal infections PCV7 failure was certain in 4 cases. The incidences of serious adverse drug reactions did not differ from our previous survey, except the incidence of thrombopenic purpura and of PCV7 failure which seems to be increasing.
Conclusions: This new study confirms the risk of vascular purpura, raises the thrombopenic purpura issue, and the emergence of PCV7 failures which will need a strict monitoring of the future 13 valences vaccine.
© 2011 Société Française de Pharmacologie et de Thérapeutique.