A substance or reactant intended to be used together with a parent IVD to perform a specific function in an assay that is used for the qualitative and/or quantitative detection of one or multiple antigens from viruses associated with respiratory diseases in a clinical specimen. Viruses intended to be detected may include respiratory syncytial virus (RSV), influenza viruses, parainfluenza viruses, human metapneumovirus, coronaviruses, enteroviruses, rhinoviruses and/or adenoviruses.