List some examples of common parental objections to immunisation and the response to these objections
- The disease is not serious - measles can kill healthy children
- The disease is uncommon - only uncommon now due to vaccines
- The vaccine is ineffective and/or unsafe - vaccines are rigorously tested for efficacy and safety before being introduced
- Other methods of disease prevention, such as homeopathy, are preferable to immunisation - no evidence that homeopathic vaccines confer long or short term protection.
- Because of the success of vaccinations, people have become complacent about the severity of a disease.
When thinking about introducing a vaccination programme, what is it important to consider?
- HOW vaccine is produced and given
- WHO is given vaccine. Whole pop? certain demographic/sex?
What percentage of immunisation coverage does WHO recommend in order to prevent an outbreak of mumps?
90%
What is herd immunity?
Where the proportion of a host population is immune to an infection. The presence of immune individuals protects those who are not immune themselves - perhaps their immune system was too weak to have vaccine or the vaccine was ineffective on them.
the idea that a disease can be eradicated even if some people remain individually susceptible.
What is the main aim of the UK immunisation programmes?
To eradicate infectious diseases
What does R0 stand for and what does it mean?
R0 = basic reproduction number
It is a way of measuring transmissibility. It is the average number of secondary cases produced by one primary case in a wholly susceptible population.
What does a large R0 value mean?
The larger the R0, the more difficult the infection is to control
What does R stand for and what does it mean?
= effective reproduction number
It’s the actual average number of secondary cases produced by an infectious primary case
What does it mean if R<1?
The infection cannot persist.
R can be reduced by reducing the number of susceptible people in the population e.g. through vaccination
What is s* and how is it calculated?
=critical proportion susceptible
= 1/R0
What is the ‘herd immunity threshold’ and what 2 equations can be used to work it out?
= the proportion of the pop. that needs to be vaccinated to prevent sustained spread of the infection
= 1-1/R0
= 1-s*
Identify some of the challenges/barriers in providing vaccinations (including flu)
- lack of understanding/education of HC providers and parents meaning you don’t get good coverage
- Lack of access - some vaccines require boosters so this may involve multiple trips to hospital
- Myths that arise in the press
- Lack of funding - if people have to pay for it they are less likely to get it
- Inadequate preclinical data
- antigenic variation requires constant updating of vaccine formulations (e.g. flu)
- high costs involved in developing the vaccines
What does the 6-in-1 vaccine protect agains?
- diphtheria
- Hepatitis B
- Haemophilus Influenzae type b (Hib)
- Polio
- Tetanus
- Whooping cough (pertussis)
At what ages are children in the UK recommended to get MMR vaccine and subsequent boosters?
1 year
and
3yrs 4 months
At what age are children recommended to have their first vaccinations in the UK?
8 weeks old
