The paramyxovirus virus that lacks both hemagglutinin and neuraminidase activities is:: (A) Mumps virus, (B) Measles virus, (C) Respiratory syncytial virus, (D) Parainfluenza virus.
Answer is C. 1. Influenza and mumps possess both haemagglutinin and neuraminidase spikes. 2. Measles possesses haemagglutinin but lacks neuraminidase spikes. 3. RSV lacks both haemagglutinin and neuraminidase spikes. The viral envelope contains a surface glycoprotein G, by which it is attached to the cell surface of the host cells. It contains F protein but lacks both H and N proteins. The F protein induces the fusion of the infected cells with adjoining cells, resulting in the formation of large multinucleated syncytia, from which the virus derives its name.