Viruses By Vinayak What is a virus? ● A virus is an infectious microbe that contains genetic material (either DNA or RNA) and surrounded by a protein coat (Capsid). ● A virus cannot replicate alone; instead, it must infect cells and use components of the host cell to make copies of itself. The discovery of a virus • Two scientists were accredited for the discovery of the Virus, Dmitri Ivanovsky • Ivanovsky reported in 1892 that extracts from infected leaves were still infectious after filtration through a Chamberland filtercandle. • Beijerinck, in 1898, was the first to coin the term 'virus', the cause of the tobacco mosaic. He showed that the pathogen was able to migrate in an agar gel, therefore being an infectious soluble agent, or a 'contagium vivum fluidum' and definitively not a 'contagium fixum' as would be a bacteria. • Beijerinck is also called the father of virology due to his discovery Types of Viruses Are there viruses that infect other viruses? • Yes • There are viruses that infect other viruses. • These are called Virophages & only infect a special, rare group called Giant Viruses • Giant viruses are viruses that have a diameter of more than 600 nanometer. How does a vaccine work? • A simple, safe, & effective way of protecting you against harmful diseases, before you come into contact with them. • They train your immune system to create antibodies for a particular disease. • They contain only killed or weakened forms of germs like viruses or bacteria, they do not cause the disease or put you at risk of its complications. The early vaccine • Edward Jenner is considered the founder of vaccinology in 1796, after he inoculated a 13 year-old-boy with vaccinia virus (cowpox), and demonstrated immunity to smallpox. • In 1798, the first smallpox vaccine was developed. • However, a practice wherein monks drink snake venom to gain immunity to it, was followed centuries before vaccination COVID - 19 • Covid 19’s full form is Coronavirus Disease and is caused by the SARS-COV2 virus • COVID-19 affects different people in different ways. • Most infected people will develop mild to moderate illness and recover without hospitalization.
