Immunisation Flashcards
What is immunisation/vaccination?
when you give a person a vaccine to prevent them becoming ill from a disease
How do vaccines work?
the vaccine contains antigens from the pathogen in the form of a dead or weakened pathogen
the person’s lymphocytes produce antibodies against the pathogen and also memory lymphocytes
if the person is infected with the real pathogen, the memory lymphocytes will give a rapid secondary response
this means that the person is very unlikely to become ill
What are the advantages of immunisation?
- immunity is produced without being ill
- immunity lasts a long time (often for life)
-if most people are immune, those who are unvaccinated are less likely to catch the disease
(herd immunity)
What does a vaccine contain?
antigens from the pathogen, often in the form of dead or weakened pathogens
(the pathogen is inactive and cannot cause disease)
What are the disadvantages of immunisation?
- some people get a mild reaction such as swelling, soreness, or a mild form of the disease
- rarely, a person has a major harmful reaction
- it doesn’t always work
Describe how a vaccine can protect you for life.
Once you have received the vaccine, the immune system makes antibodies but also memory lymphocytes which stay in the body for a long time.
If you ever catch the disease ‘for real’, these memory cells divide very quickly and produce huge numbers of antibodies.
(Make sure to refer to memory lymphocytes)
Describe the difference between a vaccine and immunisation.
A vaccine contains a dead or harmless form of a pathogen or antigenic material that is used to immunise a person.
Immunisation means giving a disease to cause an immune response in the body.
Explain why immunisation only protects you against one particular disease.
Each pathogen has a particular antigen.
The immune system produces antibodies that are exactly the right shape to fit on to these antigens.
Other pathogens have antigens of a different shape, so one kind of antibody cannot bind to a different kind of antigen.
Explain why people who have not been vaccinated against a particular disease are protected if most people are immune to that disease.
Infection can only be transmitted from an infected individual to an uninfected individual
vaccinated people are immune and so cannot become infected
if most people are immune, the chances of a vaccinated person meeting an infected person are very small
