Question

Why do scientists need to invent new vaccine for the same disease over a period of time?

Answer 1

Scientists invent a new vaccine for the same disease cause' the new vaccine is better and more reliable than the older one.


Hope it hi

Answer 2

Hyy I hope it will help you.

Scientists need to invent new vaccines for the some disease over a period of time because the pathogens causing the disease become resistant against the vaccines. Thus, the same vaccine cannot be used to provide protection against the same pathogen; thereby, a different vaccine that can effectively be used against the resistant pathogen needs to be developed in order to protect the organisms against that pathogen.