2.8 Vaccinations

Question 1

Why do people get vaccinated? (3)

Answer 1

• When you’re infected with a new pathogen it can take your white blood cells a while to produce the antibodies to deal with it. In that time you can get very ill, or maybe even die
• To avoid this you can be vaccinated against some diseases, e.g. polio or measles
• Big outbreaks of diseases (epidemics) can be prevented if a large percentage of the population is vaccinated (herd immunity)

Question 2

What do vaccinations do? (2)

Answer 2

• Vaccinations involve injecting dead, inactive or weakened pathogens into the body. These carry antigens, so even though they’re harmless they still trigger an immune response - your white blood cells produce antibodies to attack them
• Some of these white blood cells will remain in the blood as memory cells, so if live pathogens of the same type ever appear, the antibodies that help destroy them will be produced immediately

Question 3

What are the pros of vaccinations? (3)

Answer 3

• Vaccines have helped control lots of communicable diseases that were once common in the UK (e.g. polio, measles, whooping cough, rubella, mumps, tetanus..)
  Smallpox no longer occurs at all, and polio infections have fallen by 99%
• Protection from diseases
• Prevents outbreaks

Question 4

What is ‘herd immunity’?

Answer 4

This is when enough people in a population are immune to a pathogen so it wont be able to infect anyone. Once the host overcomes the disease (or dies), the pathogen dies

Question 5

What are the cons of vaccinations? (3)

Answer 5

• Vaccines don’t always work - sometimes they dont give you immunity
• You can sometimes have a bad reaction to a vaccine (e.g. swelling, or maybe something more serious such as a fever or seizure). Bad reactions are rare
• It can be expensive to make vaccines and carry out vaccination programmes - if a disease occurs only very rarely or the vaccine isn’t very effective, the cost of carrying out the programme may outweigh any benefits to society