M27 - Vaccine

Question 1

what are the 2 types of natural immunity?

Answer 1

– Active - natural recovery from infection

– Passive - maternal antibodies

Question 2

What are the 2 types of artificially acquired immunity?

Answer 2

– Vaccination (active immunisation)

– Passive immunisation

Question 3

What is passive immunisation?

Answer 3

• Specific antibodies purified from blood of donor.

* Antibodies/immunoglobu lin injected into recipient

Question 4

What are the advantages of passive immunisation?

Answer 4

immediate protection

Question 5

What are the disadvantages of passive immunisation?

Answer 5

protecting short-lived

Question 6

when is passive immunisation used?

Answer 6

When unprotected person has been exposed to infectious agent, and there is not sufficient time for the patient to develop own antibodies by active immunisation

Question 7

what is a vaccination?

Answer 7

Administration of material of ‘microbial’ origin (vaccine) to a susceptible person to stimulate their immune defences

Question 8

What does vaccination stimulate?

Answer 8

long lasting protection against a specific disease

Question 9

When does immunological memory sometimes not work?

Answer 9

drugs, alcohol ,immunocompromised

Question 10

what should an ideal vaccine do?

Answer 10

• Provide resistance to disease
– (not necessarily to infection)
• Protect for as long as possible 
• Be safe
– minimal side effects
• Be stable
• Be cheap (especially 3rd world)
• Be perceived as “good and effective”

Question 11

What are the 4 types of vaccines?

Answer 11

• toxoid
• subunit
• Inactivated (killed)
• live-attenuated

Question 12

Describe toxoids.

Answer 12

• Purified toxin treated with formaldehyde to
render it non-toxic without changing antigenicity
• Toxoids usually adsorbed onto adjuvents to
improve their stimulatory effect
• E.g. tetanus toxoid, diptheria toxoid

Question 13

What does adjuvents do?

Answer 13

cause low grade inflammation to increase success of immune response

Question 14

Describe subunit vaccines.

Answer 14

• Consist only of small portion of microbe - enough to stimulate immune response, not enough for infection
• No risk of infection
• Generally expensive
• Generally not very effective
• Conjugate vaccine;
– where subunit is attached to another protein

Question 15

Describe inactivated vaccines.

Answer 15

• Microbe is exposed to denaturing agent or heat
• Aim is loss of infectivity without loss of antigenicity
• Little risk of vaccine associated infection
• Stable
• Not possible to achieve correct balance for all microbes
• Not always effective at stimulating correct immune response

Question 16

Describe live attenuated vaccines.

Answer 16

• Microbe with reduced pathogenicity
• Aim is to stimulate immune response without causing disease
• Very good immunogens
– (stimulate correct immune response)
• Unstable
• Risk of reversion to virulence

Question 17

Describe the administration of live and killed vaccines.

Answer 17

Live- may be natural route or injection , may be single dose
Killed - injection, usually multiple doses

Question 18

Is an adjuvant needed for live or killed vaccines?

Answer 18

Live- not required

killed- usually required

Question 19

Describe the safety of live and killed vaccines.

Answer 19

live- may revert to virulence

killed- pain from injection

Question 20

What is the cost of live and killed vaccines?

Answer 20

live- low

killed- high

Question 21

what is the duration of live and killed vaccines?

Answer 21

live- usually years

killed- may be long or short

Question 22

what is the immune response of live and killed vaccines?

Answer 22

live- IgG, IgA, cell-mediated

killed - mainly IgG, little or no cell-mediated

Question 23

What are common side effects of vaccines?

Answer 23

swelling and redness at injection site, transient fever, malaise, headache

Question 24

What are rare side effects of vaccines?

Answer 24

– anaphylactic shock

– have adrenalin and oxygen available

Question 25

Name complications of vaccines.

Answer 25

• “live” material in “killed” vaccine preparation • Allergic effects – e.g. influenza virus is grown in eggs • Toxicity – e.g. typhoid vaccine (vaccine contains large numbers of killed Salmonella typhi so large amounts of endotoxin)

Question 26

who should live vaccines not be given to?

Answer 26

• Pregnant women - unless significant risk of exposure outweighs risk to foetus • Immunosuppressive treatment – Individualsonhighdosesofsteroids – with malignant conditions - • lymphomas, leukaemia; • HIV +ve patients should not get BCG vaccine

Question 27

what is herd immunity?

Answer 27

the level of disease resistance of a community or population

Question 28

Describe how herd immunity works.

Answer 28

– Sufficient levels of immunised people to prevent circulation of disease & infection of non-immunised. – Applies only to diseases that pass form person to person – Ultimately herd immunity leads to eradication

Question 29

Name factors effecting herd immunity.

Answer 29

``` – Environmental • Population density • Time of year – Immunestatus • HIV – Vurulence of disease • Measles highly infectious >90% protection required for herd immunity • Varies but 90% a common figure. ```

Question 30

Describe measles.

Answer 30

* Highly contagious viral illness * First described in 7th century * Near universal infection of childhood in pre- vaccination era * Frequent and often fatal in developing worlds

Question 31

Name conditions caused by measles complications and 5 reported.

Answer 31

- Diarrhea (8%) - Otitis media (7%) - Pneumonia (6%) - Encephalitis (0.1%) - Hospitalization (18%) - Death (0.2%)

Question 32

Name adverse reaction from MMR.

Answer 32

* Fever * Rash * Joint symptoms * Thrombocytopenia * Parotitis * Deafness * Encephalopathy

Question 33

Describe the vaccination paradox in the post factual era.

Answer 33

- Increased vaccine safety - Increased vaccine coverage - Decreased disease incidence - Decreased doctors trust - Decreased parents trust

Question 34

Name some childhood vaccines.

Answer 34

- Meningitis C - Rotavirus - MMR - Chickenpox - BCG (TB) - Flu - HepB

Question 35

What is human papilloma virus (HPV)?

Answer 35

• Cervical Cancer – 1000UKdeathsperanum • 18 Yrs (25%) • 24 Yrs (40%) • HPV types – 16,18,

Question 36

What has been in place since 2009 for HPV?

Answer 36

– Vaccination for 15-17Yrs – Types 16 & 18 Protection – Prevent 70% of cervical cancer cases

Question 37

Name some adult vaccines.

Answer 37

* Flu Vaccine (65 years and older every year) * Men ACWY (teenage and university) * Pneumococcal (PPV) (65 years) * Whopping Cough (Pertusis)

Question 38

Give summary slide.

Answer 38

``` • Active & Passive immunisation • Ideal Vaccine & four types • Herd immunity • Contra-indications, side effects • Childhood vaccines – Diseasescontrolled, • Adult vaccines – Specific uses & targeted diseases • MMR & perception of vaccines ```