Vaccination

Communicable (infectious) diseaseViral diseasesBacterial diseasesFungal and protist diseasesHuman defence systemsVaccinationAntibiotics and painkillersThe discovery and development of drugsMonoclonal antibodiesPlant diseasePlant disease detection

Exam questions worksheet

Introduction

Vaccination is a method of preventing illness by introducing small quantities of dead or inactive forms of a pathogen into the body. This stimulates the white blood cells to produce antibodies. The antibodies attach to and destroy the inactive pathogen.

If the same, living pathogen enters the body in the future, the white blood cells can quickly recognise it and produce the correct antibodies to prevent infection and disease. This fast response means the body can fight off the pathogen before it causes illness.

The vaccination process

An inactive form of the pathogen (such as a virus) is injected into the body.
White blood cells detect the inactive pathogen and produce antibodies.
Antibodies attach to the pathogen and destroy it.
If the active pathogen later enters the body, the white blood cells can quickly produce the right antibodies to destroy it, preventing illness.

Herd immunity and reducing the spread of disease

When a large proportion of the population is vaccinated, the spread of the pathogen is greatly reduced. This is because the pathogen has fewer people it can infect, which means it cannot reproduce and spread easily. This offers indirect protection to those who are not vaccinated, as they are less likely to come into contact with the pathogen.

Examples of vaccination success

Countries with extensive vaccination programmes, like the UK, have successfully reduced or eliminated many diseases. Vaccines for diseases like tetanus, measles, mumps, and rubella have significantly reduced infection rates. Some countries, however, may not have the resources or infrastructure to offer widespread vaccination, so these diseases still occur.

A notable example of vaccination success is the complete eradication of smallpox, and polio cases have fallen by 99% worldwide. Additionally, during the COVID-19 pandemic, vaccines played a crucial role in preventing infections by some strains of the virus and offering protection against others.

Podcast

Quiz

Page updated

Google Sites

Report abuse