The assessment of OPV vaccines by the monkey neurovirulence test: why and how to qualify the experts in histology of central nervous system

Prior to batch release of oral poliovirus vaccines (OPV) for marketing purpose, the World Health Organisation (WHO) and European pharmacopoeia require a monkey neurovirulence test to be performed both by the manufacturer and the relevant National Control Laboratory (NCL) to assess vaccine safety as regards neurovirulence. Due to the subjectivity of histological examination and of neural lesions scoring, the French NCL has set up a proficiency testing procedure to qualify a new expert. (C) 2002 Elsevier Science Ltd. All rights reserved.