NEET BIOLOGY

Detailed explanation-1: -Once you’ve been exposed to a virus, your body makes memory cells. If you’re exposed to that same virus again, these cells recognize it. They tell your immune system to make antibodies against it.

Detailed explanation-2: -When antibodies attach to an antigen (think a lock–key configuration), it signals other parts of the immune system to attack and destroy the invaders. This is how the human body develops immunity (acquired) to a particular disease. But some germs and viruses are very adaptive.

Detailed explanation-3: -Vaccination: The act of introducing a vaccine into the body to produce protection from a specific disease. Immunization: A process by which a person becomes protected against a disease through vaccination. This term is often used interchangeably with vaccination or inoculation.

Detailed explanation-4: -Humans have three types of immunity-innate, adaptive, and passive: Innate immunity: Everyone is born with innate (or natural) immunity, a type of general protection. For example, the skin acts as a barrier to block germs from entering the body.