Lecture 11. Public Health 2: What are the Current Immunisation Policies in the UK and Why?

Question 1

What is JCVi and what is there role?

Answer 1

Joint Committee on Vaccination and Immunisation
Advises Department of Health (comes under NICE umbrella)
Has a statutory right that if the health minister want a recommendation from the JCVI, they have to follow the JCVI’s advice

Question 2

What is the Green Book?

Answer 2

Has information about every vaccine
Every GP has one and it is updated very so often

Question 3

What does the Green Book contain?

Answer 3

Schedule for routine immunisation

Question 4

Why is there a pressure to amalgamate vaccines with similar due dates together?

Answer 4

Parents don’t want to keep bringing their children to the GP -want to get every vaccine done at once (some can’t be given together as efficacy is reduced)

Question 5

Why are most of the vaccines given to the very young?

Answer 5

Because you want to protect them for as long as possible (most of these vaccines will last their lifetime)

Question 6

When is the measles, mumps and rubella (MMR) vaccine given, and when is the booster given?

Answer 6

Initial injection - One year old (on or just after birthday)
Booster - Three years four months old or sooner

Question 7

What are the five aims of public health interventions?

Answer 7

Control
Elimination of Disease
Elimination of Infection
Eradication
Extinction

Question 8

What is the aim of control?

Answer 8

Reduction of disease incidence, prevalence, morbidity or mortality to a locally acceptable level as a result of deliberate efforts. Continued intervention measures are required to maintain the reduction

Question 9

What is the aim of elimination of disease?

Answer 9

Reduction to zero of the incidence of a specified disease in a defined geographical area as a result of deliberate efforts. Continued intervention measures are required

Question 10

What is the aim of elimination of infection?

Answer 10

Reduction to zero of the incidence of infection caused by a specified agent in a defined geographical area as a result of deliberate efforts. Continued measures to prevent re-establishment of transmission are required
Some diseases have infection eliminated before disease

Question 11

What is the aim of eradication?

Answer 11

Permanent reduction to zero of the worldwide incidence of infection caused by a specific agent as a result of deliberate efforts. Intervention methods are no longer needed

Question 12

What is the aim of extinction?

Answer 12

The specific infectious agent no longer exists in nature or the laboratory

Question 13

What is an example of a disease that was controlled?

Answer 13

Haemophilus influenzae B (HiB), booster introduced in 2006 after honeymoon phase wore off

Question 14

How diphtheria eliminated locally (not worldwide)?

Answer 14

Introduction of immunisation in 1940 eliminated the pathogen - massive reduction in both infections and deaths

Question 15

Why does the number of measles cases per year zigzag?

Answer 15

Measles outbreak alternate between small and large outbreaks (one year small outbreak, next year big outbreak)

Question 16

Because the R₀ of measles is so high, what percentage of the population would need to be vaccinated to ensure herd immunity?

Answer 16

~97%

Question 17

Why was there a measles outbreak in Swansea in 2012?

Answer 17

A local newspaper was publishing anti-vaxx messages

Question 18

What vaccine led to a huge drop in Polio cases in 1962?

Answer 18

Sabin

Question 19

Since 2004, why did doctors switch from OPV (live attuned oral polio vaccine) to IPV (inactivated polio vaccine)?

Answer 19

IPV has a lower risk than OPV
Get away with less effectiveness as polio is less prevalent within the population

Question 20

When was the WHO European Region (EUR) deemed free of indigenous poliovirus transmission?

Answer 20

21 June 2002

Question 21

What were the first two WHO regions deemed polio free?

Answer 21

Region of the Americas - 1994
Westen Pacific Region - 2000

Question 22

How many estimated people live in countries and territories that are certified free of endemic wild poliovirus transmission?

Answer 22

3.4 billion

Question 23

What three countries have not stopped polio transmissions?

Answer 23

Pakistan
Afghanistan
Nigeria

Question 24

How many reported cases of poliovirus were there in 2017?

Answer 24

22

Question 25

When did the smallpox eradication campaign take place?

Answer 25

1967-77

Question 26

When did the dracunculiasis (Guinea worm) eradication campaign take place?

Answer 26

1980 - should also result in extinction (dogs identified are reservoir hosts)

Question 27

What are the main problems with vaccines?

Answer 27

Immunogenicity
Reactogenicity (side effects of vaccine)
Coverage - proportion of the population immunised & protected

Question 28

What is Hepatitis B (HBV)?

Answer 28

Childhood disease in most developing countries – Mass immunisation as soon as possible after birth
Adult, risk behaviour associated infection in most developed countries - Mass immunisation vs. Targeted immunisation of identified risk groups
This is a question with health-economics can have a substantive input

Question 29

What’s more expensive, mass immunisation or targeted immunisation?

Answer 29

Targeted

Question 30

What does HBV result in death?

Answer 30

HBV causes deaths chronic infection leading to liver disease, which develops over years

Question 31

What are the pros and cons of mass immunisation?

Answer 31

Mass immunisation is very effective, but there is a delay of 15yrs until the effect is seen (because of start of risk behaviours)
Mass immunisation results in 1 carrier prevented per 200 doses

Question 32

What are the pros and cons of targeted immunisation?

Answer 32

More effective immediately than mass immunisation, but overtaken at about 25 years before effect seen
Targeted immunisation is much more cost-effective (carries prevented per dose of vaccine given)

Question 33

What is the current incidence of HBV?

Answer 33

Very low (~500 per year), but not zero

Question 34

Why hasn’t HBV been eradicated?

Answer 34

Too costly to eradicate the last places

Question 35

What countries are resisting the global momentum to vaccinate everybody and why?

Answer 35

UK, The Netherlands and Scandinavian countries
This will be a barrier to eradication since individuals start risk behaviours before they are immunised
Economics of immunisation mean that a mass programme in UK is expensive and not cost-effective

Question 36

What caused the additional complications of HBV eradication?

Answer 36

Caused by age-related risks of becoming a carrier

Question 37

What HPV and what are the symptoms?

Answer 37

Human papilloma virus
Genital warts and cervical cancer (cervical cancer is the biggest effect and the most costly)
Sexually transmitted

Question 38

Which disease causes a bigger burden on the NHS, HBV or HPV?

Answer 38

HPV

Question 39

What are the population consequences of vaccination?

Answer 39

Immunisation reduces the number of susceptibles
Makes infection rarer - those not vaccinated will be infected later in life: possibly with more disease which makes vaccine relatively more more dangerous
Changes the dynamics
Older population more at risk

Question 40

What caused the sharp rise in pertussis cases in 2011?

Answer 40

Children were too young to immunise, therefore mass emergency vaccines were given to mothers in the last trimester so maternal antibodies could give the babies immunity