Answer:
Biological hazary are natural scenarios involving disease, disability or death on a large scale among humans, animals and plants due to micro-organisms like bacteria, or virus or toxins.
The H1N1 virus (Cause 9f Swine flu) is believed to have begun its deadly journey in pigs from a small region of central Mexico in January 2009. By March, the first cases were reported in California and Texas. By June, it was in 74 countries across the globe. A year later, when the WHO declared an end to the pandemic, between 151,700 and 575,400 people had died.
A massive global vaccine effort led by the US helped end the pandemic, but the H1N1 virus is still with us. Every year it circulates as a seasonal flu, causing sickness, hospitalisation and dead