KA7 Immunisation Flashcards
How can immunity be developed?
Through vaccinations using antigens from infectious pathogens, so creating memory cells
What are the antigens used in vaccines?
Inactivated pathogen toxins
Dead pathogens
Parts of pathogens
Weakened pathogens
What are antigens usually mixed with when producing a vaccine?
An adjuvant
What is an adjuvant?
An adjuvant is a substance which makes the vaccine more effective, so enhancing the immune response
When does herd immunity occur?
When a large percentage of the population is vaccinated
What is herd immunity and why is it important?
If a large percentage of the population are immunised by vaccination, non immune individuals are protected since there is a lower probability that they will come into contact with infected individuals.
Establishing herd immunity is important in reducing the spread of diseases
What is the herd immunity threshold?
The percentage of immune individuals in a population above which a disease cannot persist
What does the herd immunity threshold depend on?
Type of disease
Effectiveness of vaccine
Density of the population
What are mass vaccination programmes designed to establish?
Herd immunity to a disease
Why is it harder to establish herd immunity in a DEVELOPING country
Difficulties can arise when widespread vaccination is not possible due to poverty (not a persons choice)
Why may herd immunity be comprised in a DEVELOPED country?
Difficulties arise when vaccines are rejected by a percentage of the population (a persons choice)
What is antigenic variation?
Some pathogens can change their antigens, this means that memory cells are not effective against them
Why is a new influenza vaccine needed each year?
Antigenic variation occurs in the influenza virus explaining why it remains a major public health problem and why individuals who are at risk require to be vaccinated every year
