Immunity
Before we begin, here are some terms which you should familiarise yourself with.
Active immunity is where antibodies are made by the immune system of the immune system and thus retains memory and can respond rapidly on second exposure. However, this can also cause adverse effects from the infection
Passive immunity is where antibodies produced in one person are introduced into another person to provide immunity and thus provides immediate protection but has no memory and doesn’t provide lasting protection
Vaccines are used to activate the immune system to produce antibodies against specific disease-causing organisms without causing the disease. This is because the pathogens can be killed or weakened so they cannot cause harm
Herd Immunity is the indirect protection of populations from infection where that protection is created by the presence of immune individuals as it decreases the possibility for a contagious infection to be present. This protects vulnerable members of society e.g. elderly people who are unable to access the vaccine
Monoclonal antibodies are specially artificially designed antibodies to target one specific antigen
Autoimmune diseases occur when the immune system fails to recognise ‘self’ and produces antibodies against the body’s own cells. These antibodies are called autoantibodies
Multiple sclerosis is an autoimmune disease that results from autoantibodies attacking the myelin that forms an insulating sheath around nerve fibres in the brain and spinal cord. When the myelin is destroyed, nerve fibres are exposed, and the transmission of nerve impulses is slowed or blocked which can lead to numbness, lack of coordination and vision impairment
Acquired immunodeficiency syndrome is a disease that results from an uncontrolled and untreated infection by the human immunodeficiency virus. HIV is a retrovirus that carries its genetic information in two fragments of single stranded RNA. The HIV targets the T helper cells of the immune system, thus crippling it, as the gradual depletion of T helper cells means that the immune system ceases to protect against pathogens
The immune system of those with untreated AIDS are suppressed and these people are at risk of opportunistic infections which are pathogens that take advantage of the weakened immune system
An allergic reaction is an abnormal reaction of the immune system to an allergen. Allergens such as pollen, dust, peanuts react with IgE antibodies attached to mast cells – primed mast cells. They develop via sensitisation