Vaccination and Immunisation

Question 1

What are the essential characteristics of vaccines?

Answer 1

• Must provide effective protection without risk of causing disease or severe side effects.
• Protection should be long-lived.
• Stimulate correct arm of immune response.
• Stimulate neutralising antibodies to prevent re-infection.
• Stable for long-term storage and transport.
• Economically affordable for widespread use

Question 2

Name the different types of vaccines

Answer 2

Life, Attenuated, killed, extract, recombinant and DNA.

Question 3

Describe what a live vaccine?

Answer 3

Organisms capable of normal infection and replication. Therefore they cannot be used against pathogens that cause severe disease.

Question 4

Describe attenuated vaccines

Answer 4

Organism is live but ability to replicate and causes disease is reduces by chemical treatment or growth-adaptation in non-human cell lines.

Question 5

Describe killed vaccinations

Answer 5

Organism killed by physical or chemical treatment. It is incapable of infection or replication but can still provoke a strong immune response

Question 6

Describe extract vaccines

Answer 6

Materials derived from disrupted or lysed organism, eg, capsular polysaccharides. These are used when there is a risk of an organism surviving inactivation steps.

Question 7

Describe recombinant vaccines

Answer 7

Genetically engineered to alter critical genes. Often can infect and replicate but doesn’t induce associated disease

Question 8

Describe DNA vaccines

Answer 8

Naked DNA injected. Host cells then pick up DNA and express pathogen proteins that stimulate the immune response

Question 9

What vaccine is best?

Answer 9

Generally the most effective vaccines have been live or attenuated as they stimulate the immune response in a manner which most closely resembles normal infection. Tends to be the more safe the vaccine, the less effective it is.

Question 10

Describe features of herd immunity

Answer 10

This is the beneficial impact of vaccination which means if enough people are immunised then the chances of an unprotected person meeting a pathogen becomes small.

Question 11

What is DTaP/IPV/Hib vaccine?

Answer 11

Diptheria, tetanus, pertussis, Inactivated polio vaccine, Haemophilus influenza type B (6 in 1 vaccine)

Question 12

Men C vaccine?

Answer 12

Meningococcal C conjugate

Question 13

DTaP/IPV vaccine?

Answer 13

Booster vaccine for diptheria, tetanus, pertussis and polio

Question 14

Td/IPV vaccine?

Answer 14

Booster vaccine for tetanus, diptheria and polio

Question 15

Who is offered the pneumococcal vaccine given too?

Answer 15

It is offered to 65years and over individuals

Question 16

Describe the reverse vaccinology for Meningococcal B

Answer 16

1) Whole bacterial genome is sequences,
2) 600 candidate genes identified.
3) 350 expressed in E.coli bacteria in lab.
4) 344 proteins purified and used to generate antisera in mice
5) 91 novel surface molecules identified
6) 28 bactericidal sera identified
7) 5 vaccine candidates in clinical trials. Total time =24-36 months

Question 17

What do dendritic cells express and what is their role?

Answer 17

Pattern recognition receptors which are members of the toll-like receptor family. They recognise components of pathogens

Question 18

What do TLR4 recognise?

Answer 18

Lipopolysaccharides and heat shock proteins.

Question 19

What is the role of dendritic cells?

Answer 19

They encounter antigens in the periphery and become activated, then migrate to lymph nodes where they activate T cells to become effector cells.

Question 20

What occurs when CpG is included with HepB or flu vaccines?

Answer 20

It increases antibody or interferon gamma secretion