Because
vaccine co-administration can affect elicited immune responses, it is important to evaluate new
vaccines in the context of pre-existing vaccination schedules. This is particularly necessary for new pediatric
vaccines, as the World Health Organization's infant immunization program already schedules several
vaccines to be administered during the first months of life. To facilitate the assessment of inter-
vaccine interference, we developed a pediatric
vaccine multiplex assay (
PVMA) to simultaneously measure
antibodies against
vaccines commonly administered to infants, including
hepatitis B, Haemophilus influenzae type B,
diphtheria,
tetanus,
pertussis,
rubella, and respiratory syncytial virus (RSV). Comparison of antibody concentrations determined by
enzyme-linked
immunosorbent assays (ELISAs) and the
PVMA demonstrated that the
PVMA is highly sensitive, specific, reproducible, and accurate. Moreover, the
PVMA requires half the time to assess a cohort compared to ELISAs, and only costs marginally more. Demonstrating the utility of the assay, we employed the
PVMA to assess
vaccine interference in the setting of a candidate
vaccine, using the infant
HIV vaccines from the completed Pediatric
AIDS Clinical Trials Group (PACTG) protocols 230 and 326 as examples. There was no substantial difference in antibody concentrations between
vaccine and placebo recipients, which suggests that HIV vaccination did not disrupt antibody responses elicited by routine pediatric
vaccines. Thus, the
PVMA is a reliable, high-throughput technique that requires minimal sample volume to measure multiple antibody concentrations concurrently, and is an efficient alternative to ELISAs for the measurement of
vaccine-elicited antibody responses in large cohorts.