5.15: dis/advantages of immunisation

What is herd immunity?

When the majority of the population has immunity against a serious disease, people who aren’t immune will still be protected as they are less likely to come into contact with an infected person (since there are fewer of them in the population)

If the majority of the population aren’t immune to a certain disease, what happens?

When a few people are ill with contagious diseases, these can spread rapidly and develop into mass infection because most people aren’t immune

When most of the population aren’t immune to a specific disease, some are immune and healthy, but some aren’t immune and are unwell and contagious, what happens?

Mass infection can happen, but the small number of immune individuals will stay healthy and some that aren’t immune will also stay healthy

When the majority of the population has immunity and is healthy, but a few don’t have immunity but are still healthy, what happens

The majority are protected due to their immunity, and although a few individuals will become unwell, most non-immunised people will still have protection against the disease

What are advantages to immunisation?

They stop individuals from becoming ill, herd immunity can happen if enough of the population are immunised, vaccines are often much cheaper than treating ill people, and the chance of falling seriously ill or dying from the disease may be greater than the chance of experiencing a side-effect

What are disadvantages to immunisation?

Vaccines often cause people to have mild reactions, and some people have concerns that vaccines cause disabilities such as autism