1. Vaccines
a. Vaccines are preparation of microorganisms or their products used to prevent or treat diseases.
b. Preparation of antigenic proteins of pathogens on inoculation into a healthy person provides against a particular disease.
2. Prions
The word 'prion' means proteinaceous particle, i.e., pathogenic viral particles containing only proteins. But they do not contain . They are the rod-shaped cell surface glycoprotein found in neurons.