how immunization came in limelight 

Dear student.

Process of immunisation came in limelight from the idea of vaccination.

Please refer the link below:

https://www.meritnation.com/ask-answer/question/give-the-importance-of-vaccination/why-do-we-fall-ill/9962357 

https://www.meritnation.com/ask-answer/question/how-gave-the-idea-of-vaccination-and-how/why-do-we-fall-ill/6956551 

Regards.