Vaccination

• A vaccine contains a dead or altered form of the disease-causing pathogen. It contains a specific antigen to be introduced into the body.
• The vaccines work by:

  producing complementary antibodies.

  creating memory cells.
• if the body encounters the same pathogen again it will respond quickly.
• Vaccines are considered relatively safe as they only give mild symptoms of a fever and swelling at injection sites.
• Herd immunity is when enough people are immunised against a disease to protect those who cannot be immunised.( pregnant + elderly)
• During primary infection, the antibodies slowly increase, peak at around 10 days, and then gradually decreases.
• During secondary infection, the antibodies are made much quicker and to a much higher level to prevent infection.