Thrombocytopenic purpura after measles, mumps and rubella vaccination: A retrospective survey by the French Regional Pharmacovigilance Centres and Pasteur-Merieux serums et vaccins

Background. Thrombocytopenic purpura (TP) after vaccination with measles, mumps and rubella has occasionally been reported. Objectives. To evaluate the incidence and characteristics of thrombocytopenic purpura reported in France after measles, mumps or rubella vaccination with monovalent or multivalent vaccines, Methods. A retrospective epidemiologic survey was conducted. AU confirmed cases of TP reported spontaneously either to the French Regional Pharmacovigilance Centres or to the manufacturer (Pasteur-Merieux Serums ct Vaccins) between 1984 and June 30, 1992, were reviewed. Results. Sixty cases of TP in children between 1 and 11 years of age occurred 2 to 45 days after administration of 1 of 7 vaccines. The reported incidence of TP varied from 0.17 and 0.23/100 000 doses of measles or rubella vaccines, respectively, given alone to 0.87/100 000 doses of combined measles-rubella vaccines and 0.95/100 000 doses of the measles-mumps-rubella vaccine. The mean platelet count was 8000 +/- 6000/mm(3) and was lower than 10 000/mm(3) in 58% of cases. The immediate outcome was favorable in 89.5% of cases. Conclusions. According to the clinical course and biologic findings, vaccine associated TP appears to be similar to that occurring after natural measles or rubella infections and is not distinguishable from acute childhood idiopathic thrombocytopenic purpura not associated with vaccination. Such observations, combined with a clear temporal relationship between measles mumps-rubella vaccination and the occurrence of TP, make a causal relationship highly plausible. Nevertheless the incidence of these events remains relatively low with a favorable immediate outcome.