Describe a medical advance that has led to a decrease in the spread of communicable diseases. what is the advance? how does it prevent the spread of disease?

Communicable disease or also known as infectious disease is the spread of disease from one person to another in a variety of ways: through air, contact with bodily fluids, discharges or blood, direct contact, and bites. Through the years, medical science had created lots of ways to control and prevent the spread of such diseases. One of these is the development of Immunization. Immunization works by preparing the body to fight foreign microorganisms that may harm the body. This boosts the body's natural defense against bacteria and virus by allowing the body to release more antibodies. This would enable to body to recognize the possible virus or bacteria that might invade inside the system.

Hydrosphere is the correct answer