Specificity: Specific for the nucleoprotein of the SARS virus (IFA & ELISA) and COVID-19 virus (ELISA). Negative for human coronaviruses 229E & OC43. Reactive with the nucleocapsids of Variants: UK B.1.1.7, SA B.1.351, Brazil P.1 & B.1.617.2. Purified pr