Risk of serious neurologic disease after immunization of young children in Britain and Ireland.

Abstract

OBJECTIVE:

We sought to investigate the risk of serious neurologic disease after immunization in early childhood.

METHODS:

The results of a 3-year prospective study of children (2-35 months old) in Britain and Ireland with encephalitis and/or severe illness with convulsions and fever were linked to each child's vaccine history. Cases were reported via the British Paediatric Surveillance Unit's network. The self-controlled case-series method was used to investigate associations between immunization and acute potential adverse events. The risk periods investigated were 0 to 3 and 0 to 7 days post-diphtheria, tetanus, whole cell pertussis, Haemophilus influenzae type b or meningococcal C conjugate vaccine and 6 to 11 and 15 to 35 days post-measles, mumps, rubella vaccine.

RESULTS:

A total of 157 disease episodes from 155 children met the analytical case definition. There were 11 cases of herpes simplex encephalitis and 23 cases of primary human herpesvirus 6 and/or 7 infection. There was no evidence of a raised relative incidence of serious neurologic disease in any of the specified risk periods with the exception of a raised relative incidence of 5.68 in the 6-11 days after measles, mumps, rubella vaccine. Based on this relative incidence, between 3 and 6 of the 6 cases in this period were estimated to be attributable to the vaccine with a best estimate of 5. The 6 cases all had fever with convulsions lasting >30 minutes; in all but 1, there was complete recovery by discharge from hospital. Of the 5 patients who recovered, 1 had a concurrent primary human herpesvirus 6 infection and one a primary human herpesvirus 7.

CONCLUSIONS:

Six to 11 days after measles, mumps, rubella vaccine there is an increased risk of fever and convulsions lasting >30 minutes. All 6 of the episodes temporally related to immunization met the criteria for complex febrile convulsions. The estimated attributable risk of serious neurological disease was similar to that previously found for measles vaccine.

• Authors: Katherine N Ward, Naomi J Bryant, Nick J Andrews, Jennifer S Bowley, Anu Ohrling, Christopher M Verity, Euan M Ross, Elizabeth Miller
• Journal: Pediatrics (Pediatrics) Vol. 120 Issue 2 Pg. 314-21 (Aug 2007) ISSN: 1098-4275 [Electronic] United States
• PMID: 17671057 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Measles Vaccine
• Meningococcal Vaccines
• Mumps Vaccine
• Rubella Vaccine
• serogroup C meningococcal conjugate vaccine

Topics

• Child, Preschool
• England (epidemiology)
• Humans
• Infant
• Ireland (epidemiology)
• Measles Vaccine (adverse effects)
• Meningococcal Vaccines (administration & dosage, adverse effects, immunology)
• Mumps Vaccine (adverse effects)
• Nervous System Diseases (epidemiology, virology)
• Prospective Studies
• Risk Factors
• Rubella Vaccine (adverse effects)
• Vaccination (adverse effects)