Humans were battling for survival before evolution till our modern lifestyle. Amongst all, viruses are such tiny organisms keep infecting a humans a decades ago and spreading in universe by many routes/pathways. Animal to human transmission is triggered outbreaks claiming thousands of lives, in a period of time by different species of viruses. RNA genome viruses are assumed to more virulent than DNA genome one due to its complex structural instability , environmental adoptability, mutational properties. Study of its entry in human body, attachment and replication into host cells, response of host defence cells by innate and adaptive immunity is helpful to know virus’ mild to lethal pathogenic nature. Marburg, Ebola, HIV,influenza, SARS-COV, and 2019 –nCoV( COVID 19 /SARS-COV2) are few deadly threats of a battle. Study by lab investigation, vaccines, antiviral drugs need to focus on antidisease approach then anti pathology visionary to eradicate and protect human from viruses’ bioweapon use.