By Dean L. Winslow, MD, FACP, FIDSA

Professor of Medicine, Division of General Medical Disciplines, Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine

Dr. Winslow reports no financial relationships relevant to this field of study.

SYNOPSIS: In Queensland, Australia, rotavirus vaccine was shown to be 36% effective in preventing emergency department (ED) presentation for febrile seizures among children up to two years following vaccination.

SOURCE: Sheridan SL, Ware RS, Grimwood K, Lambert SB. Febrile seizures in the era of rotavirus vaccine. J Ped Infect Dis Soc 2016;5:206-209.

Vaccine effectiveness in preventing ED presentation and subsequent hospitalization for febrile seizures was calculated using routinely collected health data. The method used involved comparing the proportion of children with febrile seizures who were vaccinated with rotavirus vaccine (PCV) with the proportion of the target population vaccinated (PPV). PPV values were obtained from the Australian Childhood Immunisation Registry (ACIR). To determine PCV, Queensland Health Data Linkage unit used data-matching software to probabilistically match vaccination data with ED presentation data. vaccine efficacy (VE) was assessed over an observation period of one year for 12-month birth cohorts.

During the study period, there were 2,211 ED presentations for febrile seizures, and 635 (29%) children were hospitalized. Among children between 8 months of age and 31 months of age, VE for the full three-dose rotavirus vaccine series in preventing febrile seizures resulting in ED visit was 36%, and 38% for prevention of subsequent hospitalization. This protective effect of rotavirus vaccination persisted up to four years after vaccination.

COMMENTARY

The VE of 36% for prevention of any febrile seizure is generally consistent with the U.S. finding of a 21% reduction of all childhood seizures requiring ED care or hospitalization in the first year after rotavirus vaccination.1 The use of the Queensland linked dataset demonstrated a more profound effect, likely because of its ability to tease out febrile from afebrile seizures. Since serologic studies and/or viral isolation or polymerase chain reaction (PCR) was not performed in this study, the precise mechanism of the rotavirus vaccination’s protective effect on febrile seizures in these young children is not completely established.

Interestingly, another U.S. study showed that rotavirus infection was associated with new onset of febrile seizures in 8% of children and in 21% of children presenting with afebrile seizures.2

One potential source of confounding in this Queensland study was that it may have been more likely that children who received rotavirus vaccine also were more likely to have received influenza B vaccine (another common cause of febrile seizures). In any case, the results are very positive and demonstrate an additional unanticipated beneficial protective effect of rotavirus vaccination on preventing childhood seizures, in addition to its efficacy in preventing the most common cause of childhood diarrhea seen in the developed world.

REFERENCES

  1. Payne DC, et al. Protective association between rotavirus vaccination and childhood seizures in the year following vaccination in US children. Clin Infect Dis 2014;58:171-177.
  2. Martin ET, et al. Redefining outcome of first seizures by acute illness. Pediatrics 2010;126:1477-1484.