Vaccination

Vaccination is a method of providing immunity using a dead or inactive form of a pathogen.

1. An inactive form of the pathogen (such as a virus) is injected into the body.

2. White blood cells detect the inactive pathogen and produce antibodies.

3. Antibodies attach to the inactive pathogen and destroy it.

4. Memory cells remain in the blood

5. If the active pathogen later enters the body, the memory cells can quickly produce the right antibodies to destroy it, preventing illness.

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.

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.