Effective February 13, the Food and Drug Administration (FDA) has reclassified rapid influenza virus antigen detection test systems (RIDTs) that are currently regulated as influenza virus serological reagents from class I into class II with special controls. The agency made this decision in response to mounting reports of the poor performance of RIDTs in the field, compounded by the emergence of new influenza strains with the potential to create a public health emergency. The new special controls for RIDTs stipulate that: 1) RIDTs must meet minimum clinical performance criteria for sensitivity and specificity; 2) manufacturers must use a currently appropriate and FDA-accepted comparator method when establishing assay performance; 3) annual analytical reactivity testing of RIDTs must be performed with contemporary influenza strains; and 4) if the secretary of Health and Human Services declares an emergency or potential emergency for an influenza viral strain, manufacturers must perform emergency analytical reactivity testing with that viral strain.