Vaccination

Question 1

Vaccination

Answer 1

Vaccination: A way of stimulating an immune response, providing immunity to specific diseases.
Created by deliberate exposure to harmless antigenic material (usually injected or orally). The antigens trigger an immune response, antibodies and memory cells (provide long-term immunity) are manufactured, without causing disease/symptoms.

Antigenic material forms:
- Similar microorganisms – ones that are not harmful but have similar antigen to actual disease.
- Harmless or attenuated (weakened) version of pathogenic organism (measles [MMR] and TB).
- Dead pathogen (cholera).
- A toxoid – harmless version of toxin.

Question 2

Control of epidemics:

Answer 2

Epidemic: A rapid spread of disease through a high proportion of the population.
Herd Vaccination: If most people in population are vaccinated the disease becomes extremely rare as few people can be infected. Non-vaccinated people are unlikely to get infected as there is no one to catch it from. Herd vaccination used to prevent epidemics (mass outbreaks of disease).
Ring vaccination: When new case of disease reported people in immediate vicinity of new case are vaccinated (surrounding houses or towns), preventing further spread of disease.
Vaccination is the administration of antigens; immunisation is the development of immunity. Vaccination causes immunisation.
Routine vaccines include:
- MMR – protects against measles, mumps and rubella. It is given to children before school, contains attenuated forms of these viruses.
- Meningitis C – protects against bacteria that causes meningitis C. Given to 3-month-old babies. Boosters then given later to make sure memory cells are still produced.

Once a disease has been eradicated/very low incidence, routine vaccination programs can be stopped (e.g. TB and smallpox).
However, some pathogens can undergo genetic mutations which change their antigens, the memory cells produced by vaccination do not recognise the new antigens, a new vaccination is needed for new strains.

Question 3

Influenza

Answer 3

Influenza – vaccination programmes:
Virus is relatively unstable and regularly undergoes genetic mutation which causes antigens on surface change forming new strain (which can cause an epidemic to arise). Memory cells produced in vaccinations for one strain won’t work for others and their receptors are specific for one antigen, different vaccines must be made each year.
WHO and CDC collect samples of different strains to identify the new antigens and test effectiveness of different vaccines / develop new ones. Governments and health authorities implement a programme of vaccination using the new vaccines. Sometimes people are vaccinated against strains in other countries – prevents global pandemic.

Question 4

Types of Immunity:

Answer 4

Active Immunity: Where the immune
system is activated by stimulation from
antigens and manufactures its own
antibodies.
Passive Immunity: Immunity achieved
when antibodies are supplied from another source (breast feeding or injection). Natural Immunity: Immunity achieved through normal life processes.
Artificial Immunity: Immunity achieved because of medical intervention.

Question 5

Tabel

Answer 5

Draw it