Question

What does COVID-19 stands for? Why vaccine for COVID-19 is difficult to prepare and taking so long?​

Answer 1

Answer:

covid 19 is the subtype of covid virus which came in year 2019 due to which it was named as covid 19.

in reality the vaccine was made in first 63 days of the arrival of virus but it is taking time as it is to mass produced.

hope it helps you