• HIV or human immunodeficiency virus is the virus that can cause AIDS.
• HIV virus infection will trigger the immune system of individuals to produce HIV antibodies against the antigen of pathogens.
• Unfortunately, the antibodies produced by the immune system in humans are unable to kill the virus.
  • This virus always changes the shape of the antigen so that it will not be recognized by the antibodies.
• HIV virus weakened and destroys the immune system of humans by attacking the lymphocyte T.
  • This virus incorporates its own RNA into the lymphocyte T and uses the lymphocyte's DNA to replicate and produce more HIV virus.
  • This process will destroy almost all lymphocyte T in the body.
  • Lymphocyte T is unable to trigger the lymphocyte B to produce antibodies and this weakens the immune system. 
  • This virus can be transferred from one individual to another through blood or body fluids.

Systemic Lupus Erythematosus (SLE)

• A chronic autoimmune disease.
• The body of SLE patients produces many antibodies that attack its own tissues. 
• SLE can occur in anybody of all ages but it usually occurs in women compared to men.
• This disease can be controlled through medication. 
• The symptoms of SME are rashes, mouth ulcers, hair fall, inflammation in the blood vessels and joints and the skin becomes sensitive towards the sunlight.
• SLE can spread to organs that can cause organ failure especially kidney failure.

Allergies

• Allergies are the body's hypersensitivity reactions that occur due to the body’s immune system reacting to allergens that enter the body.
• The body’s immune system produces antibodies to attack allergens that are considered harmful, even though the allergens are actually harmless.
• An allergen is a foreign substance, usually a protein that triggers a hypersensitive reaction.