B9 - Vaccinations

Question 1

List some examples of common parental objections to immunisation and the response to these objections

Answer 1

1. The disease is not serious - measles can kill healthy children
2. The disease is uncommon - only uncommon now due to vaccines
3. The vaccine is ineffective and/or unsafe - vaccines are rigorously tested for efficacy and safety before being introduced
4. 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.

Question 2

When thinking about introducing a vaccination programme, what is it important to consider?

Answer 2

• HOW vaccine is produced and given

- WHO is given vaccine. Whole pop? certain demographic/sex?

Question 3

What percentage of immunisation coverage does WHO recommend in order to prevent an outbreak of mumps?

Answer 3

90%

Question 4

What is herd immunity?

Answer 4

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.

Question 5

What is the main aim of the UK immunisation programmes?

Answer 5

To eradicate infectious diseases

Question 6

What does R0 stand for and what does it mean?

Answer 6

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.

Question 7

What does a large R0 value mean?

Answer 7

The larger the R0, the more difficult the infection is to control

Question 8

What does R stand for and what does it mean?

Answer 8

= effective reproduction number

It’s the actual average number of secondary cases produced by an infectious primary case

Question 9

What does it mean if R<1?

Answer 9

The infection cannot persist.

R can be reduced by reducing the number of susceptible people in the population e.g. through vaccination

Question 10

What is s* and how is it calculated?

Answer 10

=critical proportion susceptible

= 1/R0

Question 11

What is the ‘herd immunity threshold’ and what 2 equations can be used to work it out?

Answer 11

= the proportion of the pop. that needs to be vaccinated to prevent sustained spread of the infection
= 1-1/R0
= 1-s*

Question 12

Identify some of the challenges/barriers in providing vaccinations (including flu)

Answer 12

• 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

Question 13

What does the 6-in-1 vaccine protect agains?

Answer 13

• diphtheria
• Hepatitis B
• Haemophilus Influenzae type b (Hib)
• Polio
• Tetanus
• Whooping cough (pertussis)

Question 14

At what ages are children in the UK recommended to get MMR vaccine and subsequent boosters?

Answer 14

1 year
and
3yrs 4 months

Question 15

At what age are children recommended to have their first vaccinations in the UK?

Answer 15

8 weeks old