Integrate biological knowledge to develop an informed response to a socio-scientific issue.
Achievement Standard 91602 (NCEA Biology 3.2) - Internally Assessed, 3 Credits.
Navigate the knowledge tree: 🌿 Biology➡ NCEA Level 3 Biology➡ 3.2 Socio-Scientific Issue
Vaccination is the process of administering a vaccine—usually via injection, oral dose, or nasal spray—to trigger the body's immune system to produce antibodies and develop immunity against specific, often serious, diseases. It teaches the body to fight infections without causing the disease itself.
Vaccination originated from ancient practices of variolation (deliberate infection) to create immunity against smallpox, recorded in China, India, and Africa before the 18th century. English physician Edward Jenner is credited with the first modern vaccine in 1796, using safer cowpox matter to protect against smallpox.
Science Learning Hub +3
Key historical developments include:
Variolation (Pre-1700s): Centuries ago, people knew survivors of diseases like smallpox rarely caught them again. Early methods included inhaling powder from dried smallpox scabs or scratching lesion material into the skin.
Edward Jenner (1796): Jenner observed that milkmaids who contracted cowpox did not contract the deadly smallpox. He inoculated 8-year-old James Phipps with cowpox matter, proving immunity, creating the first live attenuated vaccine.
Etymology: The term "vaccination" comes from the Latin word vacca (cow), as Jenner used cowpox, notes Sabin Vaccine Institute.
Advancements (19th-20th Century): Following Jenner, Louis Pasteur developed vaccines for rabies and cholera, transitioning the practice from using naturally occurring disease to attenuated, laboratory-created vaccines.
Expansion: The first inactivated vaccines for typhoid and cholera were created in 1896, with further innovations including tetanus and diphtheria vaccines, leading to widespread eradication of diseases like smallpox in 1980.
Active immunity involves the immune system being activated either by a disease organism(virus, bacteria, fungi) or by vaccination
Passive immunity involves providing a person with the antibodies(immunoglobulins) without their immune system being involved.e,g via injection or passively via breast milk for babies
The immune system utilises three lines of defence to protect the body: physical/chemical barriers (first), non-specific innate responses (second), and specific adaptive immunity (third). The first two are innate (general) and act immediately, while the third is adaptive (specific) and develops memory to fight specific pathogens over time.
1. First Line of Defence: Physical and Chemical Barriers (Innate)
These nonspecific defences prevent pathogens from entering the body.
BioNinja
Physical Barriers: Skin (barrier, sweat), mucous membranes (traps invaders), hair, cilia.
Chemical Barriers: Stomach acid, enzymes in tears and saliva, and antimicrobial proteins.
2. Second Line of Defence: Innate Immunity (Innate)
These nonspecific defences act internally when pathogens bypass the first line.
BioNinja
Phagocytes: Scavenger cells (macrophages, neutrophils) that engulf and destroy pathogens.
Inflammation: Increases blood flow and attracts white blood cells to the infected area.
Fever: Increases body temperature to inhibit pathogen growth.
3. Third Line of Defence: Adaptive Immunity (Specific)
This system specifically recognizes and remembers pathogens, adapting over time.
National Institutes of Health (NIH) | (.gov) +3
T-Lymphocytes (T-cells): Destroy infected cells (killer T-cells) and regulate the response (helper T-cells).
B-Lymphocytes (B-cells): Produce antibodies that specifically target and neutralize antigens.
Memory Cells: Store information about past invaders for a faster, stronger response in future exposures.
Not seeing anything above? Reauthenticate
