Difference Between Active and Passive Immunity (With Table)

Immunity refers to the body’s capacity to eliminate foreign elements and germs to prevent infection. The epidermis, mucous layers, and saliva are the first line of defense against infections in the human body. When an immune system is awakened without an actual threat or is not shut down once a threat has passed, problems such as allergic reactions and autoimmune diseases develop. Immunity may be divided into two categories: active and passive.

Active vs Passive Immunity

The main difference between Active and Passive immunity is that Active immunity is based on antibodies created within the body, whereas passive immunity is based on antibodies made outside the body and then delivered into the body.

Active vs Passive Immunity

The phrase “active immunity” describes the body’s early reaction to pathogens. It may also relate to a person’s adaptive reaction to being exposed to a certain sickness or antigen. When it is exposed to a foreign antigen, such as that present in bacteria, it is also triggered. Immunity like this takes time to build.

Immunity supplied by a person through the transfer of serum or lymphocytes is known as passive immunity. They might potentially get it from someone who is extensively vaccinated. It also works immediately and without delay. Furthermore, it is just temporary. It may only survive a few months, to put it another way.

Comparison Between Active and Passive Immunity

Parameters of ComparisonActive ImmunityPassive Immunity
DefinitionImmunity to a pathogen that develops after infection is acquired is known as active immunity.Antibodies produced outside of the body offer passive immunity, which protects against illness.
Immunity typeThe immunity is mediated by both humor and cells.Only prepared antibodies are used to induce immunity.
AntibodiesThe body produces it.From a third-party source.
DurabilityLong-lasting protection is provided.It’s merely a temporary shield.
SuitabilityImmunocompromised individuals are not advised to take it.It’s safe for persons with impaired immune systems.

What is Active Immunity?

As we are exposed to novel microorganisms and unfamiliar infections, our immune systems spontaneously create active immunity. When you inhale the fresh air, eat new food, or touch new things, your immune system becomes active. Active immunity is always striving to neutralize foreign agents, so people with ordinary immune systems do not feel sick every time something new enters their body.

B cells, a kind of white blood cell, create antibodies that help in the destruction or neutralization of pathogens when the body is exposed to a new disease agent. Antibodies are y-shaped proteins that may bind to antigens found in poisons or diseases. Antibodies are disease-specific, meaning they protect the body against a certain type of disease agent.

In addition, the protection it offers is long-lasting. Because of the lag time, the protective reaction takes longer to develop. Finally, it might be reawakened by a return of illness or revaccination. It allows the immune system to detect a disease, prompting our bodies to respond by fighting it. It’s often long-lasting, and it might keep us safe from disease for the rest of our lives.

What is Passive Immunity?

Immunity supplied by a person through the transfer of serum or lymphocytes is referred to as passive immunity. They can potentially get it from someone who has had a lot of vaccinations. It’s also a fantastic way to confer resistance without having to wait for an active immune response.

Passive immunity, on the other hand, does not need prior disease agent contact. It also works instantly and without any lag time. It’s also just for a limited time. It may only survive a few months, to put it another way. Immune cells aren’t involved in the production of antibodies in passive immunity. Additionally, because it transmits directly, no antibodies are developed. Memory immune cells are also not formed.

In addition, there are no alternative options accessible in this situation. To give continuous protection, it must be re-administered on a regular basis. It is therefore useful in cases of immune deficit, immunodeficiency, or severe combined immunodeficiency.

Main Differences Between Active and Passive Immunity

  1. During active immunity, antibodies are created in the body, whereas antibodies are delivered from an external source during passive immunity.
  2. The active immunity reaction time is slower than the passive immunity response time.
  3. Passive immunity protects your body for a short period of time, but active immunity protects it for a long time.
  4. Passive immunity, in contrast to active immunity, produces an immunological memory.
  5. In most cases, active immunity comes with no negative consequences. There may be some negative side effects or responses from passive immunity.
  6. Active immunity has a lag period, but passive immunity does not.


Antibodies in our immune provide us with protection from foreign agents. In a person’s life, active immunity and passive immunity are two highly significant forms of immunity. We are considered to have active immunity when our immune system is in charge of protecting us against disease. The immunity that is active can develop spontaneously or as a result of vaccination. We are considered to have passive immunity when we are protected against a virus by someone else’s protection.


  1. https://www.ncbi.nlm.nih.gov/books/NBK513280/
  2. https://academic.oup.com/occmed/article-abstract/57/8/552/1474357