What allows the viral genome RNA to spread to other cells ?
Once inside the cell , the acidic conditions in the endosome cause two events to happen : First , part of the hemagglutinin protein fuses the viral envelope with the vacuole 's membrane , then the M2 ion channel allows protons to move through the viral envelope and acidify the core of the virus , which causes the core to dissemble and release the viral RNA and core proteins .