15 Oct Vaccines: Delaying Measles Vaccination May Increase Risk of Seizures
MedicalResearch.com Interview with:
Dr. Ali Rowhani-Rahbar PhD, MD, MPH
Kaiser Permanente Vaccine Study Center, Oakland, California
University of Washington
Department of Epidemiology Health Sciences
Seattle, WA 98195
MedicalResearch.com: What are the main findings of your study?
Answer: We found that the magnitude of increased risk of fever and seizures
following immunization with the first dose of measles-containing
vaccines during the second year of life depends on age. Specifically,
the risk of seizures attributable to the vaccine during the 7 to 10 days
following vaccination was significantly greater among children 16-23
months of age (9.5 excess cases per 10,000 doses) than among children
12-15 months of age (4.0 excess cases per 10,000 doses).
MedicalResearch.com: Were any of the findings unexpected?
Answer: I do not consider any of the findings necessarily “unexpected”;
however, they were certainly quite interesting to us. This is one of
the first studies to document a modifying effect of age on the risk of
adverse events following immunization with measles-containing vaccines.
It should be emphasized that the excess risk is small: less than 10
additional cases of febrile seizure per 10,000 doses during the 7 to 10
days following vaccination; but, the excess risk is even smaller when
children receive this vaccine on a timely basis.
MedicalResearch.com: What should clinicians and patients take away from your report?
Answer: Most important takeaway message: Timely administration of these
vaccines according to the recommended schedule is very important.
Clinicians and parents should not delay immunizing children with these
vaccines with the hope of minimizing the risk of adverse events.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Answer: Further research on the potential impact of delaying vaccination on
other health outcomes in the context of immunization safety is needed.
Rowhani-Rahbar A, Fireman B, Lewis E, et al. Effect of Age on the Risk of Fever and Seizures Following Immunization With Measles-Containing Vaccines in Children. JAMA Pediatr. 2013;():-. doi:10.1001/jamapediatrics.2013.2745.