Flashcards · Biology · Human Defences and Immunity

Immunisation

16 cards

What is a vaccine?

A preparation of an inactive or weakened pathogen that makes the body immune.
Why does a vaccine not make you ill?

The pathogen is inactive, so it cannot reproduce or cause disease.
What does a vaccine contain that triggers the immune response?

The antigens of the pathogen.
What does the body make after a vaccine?

Antibodies and memory lymphocytes.
Why is the response to a real infection faster after vaccination?

Memory lymphocytes make a secondary response.
What is a booster dose?

An extra dose given to keep the level of memory lymphocytes high.
Why does the flu vaccine change each year?

The flu virus mutates, so its antigens change.
Who developed the first vaccine?

Edward Jenner, for smallpox.
When was smallpox declared eradicated?

1980.
What is a placebo?

A harmless substance with no effect, used for comparison in a trial.
Why is a placebo used in a vaccine trial?

To compare the effect of the vaccine with no vaccine.
Give one example of a disease that has been controlled by vaccination.

Smallpox, polio, measles or diphtheria.
How is the measles vaccine different from the flu vaccine?

Measles changes very little, so one vaccine works for life.
Is a vaccine a treatment for an infection that has begun?

No. It prevents infection in future.
What is the difference between inactive and weakened pathogens?

Inactive ones are killed, weakened ones are alive but harmless.
Common mistake about vaccines?

Saying that a vaccine gives the person the disease. It does not, because the pathogen is inactive.