Vaccinations

• In the UK, we are vaccinated against a range of different diseases when we are young.
• Vaccination involves introducing small quantities of dead of inactive forms of a pathogen into the body.
• Because the pathogen is dead or inactive, it cannot lead to the disease in the patient.
• The white blood cells are not stimulated to produce antibodies against the dead or inactive pathogens.
• At the same time, the white blood cells divides by mitosis to produce lots of copies of itself.
• These copies of the white blood cells can stay in the blood for decades.
• If the same pathogen now enters the body, even years later, the white blood cells can produce the correct antibodies quickly. This prevents infection.
• When the real pathogen invaded, the antibody number rises very quickly onto a high level

  
• It is really important that a very large number of people are vaccinated against a pathogen. There are always some people who do not get vaccinated.
• If enough people get vaccinated, this also protects unvaccinated people.
• The unvaccinated person cannot catch the disease because no-one around then can pass the pathogen on.
• Scientists call this herd immunity.