What is acquired immunity?
Acquired immunity is the type of immunity that develops during a person's lifetime after exposure to disease-causing microorganisms or through vaccination. It is also called adaptive immunity because the immune system adapts to recognize specific pathogens.
This immunity provides targeted protection against particular diseases.
Acquired immunity develops when:
The body encounters a pathogen naturally
A person receives a vaccine
Antibodies are introduced from another source
The immune system produces antibodies and memory cells that help fight future infections.
In active immunity, the body produces its own antibodies.
It develops through:
Natural infection
Vaccination
Characteristics:
Long-lasting protection
Memory cells are formed
Example:
Immunity after taking a measles vaccine.
In passive immunity, ready-made antibodies are transferred to the body.
Sources:
Mother’s milk to baby
Antibody injections
Characteristics:
Immediate protection
Temporary effect
No memory cells formed
Specific to particular pathogens
Stronger after repeated exposure
Helps prevent reinfection
Acquired immunity is important because it:
Protects against infectious diseases
Supports vaccination programs
Reduces severity of infections
Helps control disease outbreaks
Acquired immunity plays a major role in modern healthcare and disease prevention.