Investigation of adverse events following immunization with liquid pentavalent vaccine in Sri Lanka
Issue
In April 2008, the Government of Sri Lanka withdrew a DTwP-HepB-Hib (fully liquid) pentavalent vaccine (Quinvaxem®) produced by Berna Biotech Korea Corporation from its national immunization programme as a precautionary measure following reports of serious adverse events following immunization (AEFIs). Subsequent investigation of the reported AEFIs and a review of the vaccine quality by WHO concluded that there was no evidence of an increased safety risk associated with Quinvaxem®. Quinvaxem® remains on the list of WHO prequalified vaccines and WHO has not recommended at any time a general withdrawal of the vaccine.
In response to continuing interest about the post-licensure safety profile of Quinvaxem®, this updated briefing note1 is being issued to inform key stakeholders, including countries considering introduction of the vaccine for routine use, about the key findings of the AEFI investigation in Sri Lanka and about WHO's current position on the safety of Quinvaxem.
To further assist all stakeholders in understanding the safety profile of Quinvaxem®), WHO is currently undertaking an expert review of the reported AEFI cases in Sri Lanka for an independent assessment of the potential causal relationship between the adverse events and the vaccine. The panel is also tasked with advising WHO on potential further steps to improve the post-marketing safety knowledge about the vaccine. A further communication will be issued when the results of the independent expert review become available in approximately four weeks.