Fatal enhanced respiratory syncytial virus disease in toddlers

<p>In 1967, two toddlers immunized with a formalin-inactivated vaccine against respiratory syncytial virus (FIRSV) in the United States died from enhanced RSV disease (ERD), a severe form of illness resulting from aberrant priming of the antiviral immune response during vaccination. Up to 80% of immunized children subsequently exposed to wild-type virus were hospitalized. These events hampered RSV vaccine development for decades. In this manuscript, we provide a characterization of the clinical, immunopathological, and transcriptional signature of fatal human ERD, outlining novel evidence for safety evaluation of RSV vaccines and a framework for understanding disease enhancement for pathogens in general.&nbsp; These are the scanned histology slides from this study. &nbsp;</p>