There was no significant difference in vaccine antigen exposure through the first 23 months of life between children with non–vaccine-targeted infections and controls between 24 and 47 months of age, according to results published March 6 in JAMA.
This was determined in a nested, matched case-control study of 193 infection cases and 751 controls, in whom estimated mean cumulative vaccine antigen exposure was 240.6 for cases of non–vaccine-targeted infections, and 242.9 for controls, reported Jason M. Glanz, PhD, of Kaiser Permanente Colorado, Denver, and his coauthors. The between-group difference was –2.3 (P = .55), a nonsignificant difference.
Using data from the Centers for Disease Control and Prevention-funded Vaccine Safety Datalink (VSD), the investigators identified children born between Jan. 1, 2003, and Sep. 31, 2013. Exclusion criteria were not having at least two well-child visits before the first birthday, medical contraindications to vaccination, or receiving vaccines not recommended by the Advisory Committee on Immunization Practices. Eligible children were followed through age 47 months or until disenrollment from their health care organization, the authors said.
ICD-9 and ICD-10 codes were used to identify non–vaccine-targeted infections, including upper and lower respiratory infections, gastrointestinal infections, and other viral and bacterial infections from ages 24to 47 months. A medical record review was performed to confirm case status. Cases were included only if it was confirmed that the infection occurred, that it was an incident outcome, that the outcome was the primary reason for the medical visit, that the outcome occurred in the inpatient or emergency department setting, and that there was no evidence that the child was diagnosed as having a vaccine preventable disease (VPD) on the same day as the infection. Controls did not have a VPD or record of a non–vaccine-targeted infection prior to the index date, Dr. Glanz and his colleagues said.