In the field of biology, various advancements once a person starts taking alcohol or drugs have helped us in gaining a better understanding to fight against various infectious diseases. Biology has helped us in studying the life cycle of various parasites, pathogens, and vectors along with their modes of transmission and controlling measures. Vaccination programs against several infectious diseases such as smallpox, chickenpox, tuberculosis, etc. have helped nearly eradicate these diseases. In the preparation of newer or safer drugs and vaccines, biotechnology has helped a lot. In treating infectious diseases the antibiotics have also played a very important role.