The five health care workers were definitively seronegative against H5 in all assays, meaning they were not infected with H5. Hemagglutinin inhibition (Hello) assay: The Hello assay exams for antibodies for the hemagglutinin of the precise influenza virus using purple blood cells (RBC). A number of sorts of RBCs ended https://www.dailypioneer.com/vivacity/ongc-always-stood-for-national-unity.html