10 Differences Between active immunity and passive immunity

Active Immunity vs Passive Immunity: Understanding the Differences

Immunity plays a crucial role in protecting our bodies against harmful pathogens and diseases. To achieve this, our immune system can be stimulated through active immunity or provided with pre-formed protection through passive immunity. In this article, we will explore the differences between active immunity and passive immunity, including their definitions, examples, uses, and advantages. By the end, you will have a clear understanding of how these two forms of immunity differ from each other.

What is Active Immunity?

Active immunity refers to the resistance developed by an individual’s immune system against a specific antigen. It occurs naturally when a person is exposed to an infectious agent or artificially when vaccines are administered. In both cases, the body produces its own immune response, including the production of antibodies and memory cells.

Examples of Active Immunity

  • Recovering from an infection: Once you recover from an illness, your body develops immunity to that specific pathogen, making it less likely that you will get sick from it again.
  • Vaccination: When a person receives a vaccine containing weakened or inactivated pathogens, it prompts the immune system to produce an immune response, creating immunity against the targeted pathogen.

Uses of Active Immunity

Active immunity has multiple uses, including:

  1. Preventing infectious diseases through vaccination
  2. Protecting vulnerable populations, such as children and the elderly, from diseases
  3. Reducing the severity of illness if a vaccinated person does contract the disease

What is Passive Immunity?

Passive immunity, on the other hand, is the immediate, but temporary, protection provided to an individual without stimulating their immune system. This immunity is acquired from another source, such as maternal antibodies passed to infants through breast milk or through the injection of pre-formed antibodies.

Examples of Passive Immunity

  • Maternal antibodies: During pregnancy, a mother transfers antibodies to her fetus through the placenta, protecting the newborn during the initial months of life.
  • Administered antibodies: In certain medical situations, such as emergency treatment for snakebites or rabies exposure, pre-formed antibodies are directly injected into a person to provide immediate protection.

Uses of Passive Immunity

Passive immunity serves several purposes, including:

  1. Providing immediate protection when there is no time for the body to develop an immune response
  2. Temporarily strengthening a weakened immune system in individuals at high risk of infections
  3. Managing certain diseases and conditions by using antibodies with specific properties

Differences Between Active Immunity and Passive Immunity

Difference Area Active Immunity Passive Immunity
Source of Immunity Self-produced through immune response Externally acquired from another source
Duration of Protection Long-lasting protection Temporary protection
Time Required to Develop Immunity Several days to weeks Immediate protection
Transferability Cannot be transferred to another person Can be transferred to another person
Need for Prior Exposure to Pathogen Does not require prior exposure to the pathogen May require prior exposure to the pathogen
Requirement for Booster Doses May require booster doses to maintain immunity No need for booster doses
Memory Cells Production Stimulates the production of memory cells for long-term protection Does not stimulate the production of memory cells
Immediate Protection Not immediately effective Immediately effective
Cost Vaccines or natural infection can be costly Can be expensive depending on the source
Availability Readily available through vaccination or recovery from infections Dependent on the availability of suitable donors or artificial antibodies


In summary, active immunity and passive immunity differ in terms of their source, duration of protection, speed of response, need for prior exposure, transferability, memory cell production, and more. Active immunity relies on the body’s immune response to produce long-lasting protection, while passive immunity provides immediate protection by using externally acquired antibodies. Each form of immunity has unique uses and benefits, and their applications depend on specific circumstances and individual needs.

People Also Ask:

Here are some common questions about active immunity and passive immunity:

1. Can active immunity be acquired without getting sick?

Yes, active immunity can be acquired through vaccination without the person contracting the actual disease.

2. Does passive immunity provide long-term protection?

No, passive immunity only provides temporary protection, as the transferred antibodies degrade over time.

3. Are booster doses required for passive immunity?

No, booster doses are not required for passive immunity, as the protection is immediate and short-term.

4. What happens to active immunity over time?

Active immunity can weaken over time, which is why booster shots are sometimes necessary to reinforce protection.

5. Can passive immunity be transferred from one person to another?

Yes, passive immunity can be transferred from one person to another through the administration of pre-formed antibodies.

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