"The OSOM Ultra Plus Flu A & B Test is an in vitro rapid qualitative test that detects influenza type A and type B nucleoprotein antigens directly from nasal swab and nasopharyngeal swab specimens obtained from patients with signs and symptoms of respiratory infection. "The OSOM Ultra Plus Flu A & B Test is an in vitro rapid qualitative test that detects influenza type A and type B nucleoprotein antigens directly from nasal swab and nasopharyngeal swab specimens obtained from patients with signs and symptoms of respiratory infection.