which virus spread the fastest and which virus had the highest death rate...Why?
The virus that is widely considered to have spread the fastest is the coronavirus (COVID-19), which quickly spread worldwide in early 2020. This rapid spread was fueled by the virus's high level of contagiousness, as well as global travel and interconnectedness allowing it to move quickly from one region to another.
On the other hand, the virus with the highest death rate is the Ebola virus, with mortality rates ranging from 25% to 90% in different outbreaks. The high death rate of Ebola is largely attributed to the virus's ability to cause severe hemorrhagic fever, leading to organ failure and death in a significant portion of those infected. Additionally, the lack of effective treatments and vaccines for Ebola has contributed to its high death rate.