Vaccines (Seminar)

Question 1

Vaccination vs. immunisation

Answer 1

vaccination: administration of antigenic material

immunisation: the process whereby a person is made immune (typically through a vaccination)

Question 2

Inventor of vaccines

Answer 2

Edward Jenner
vaccine against small pox based on cow pox

Question 3

pioneers in vaccinology

Answer 3

Albert Calmette & Camille Guerin:
- BCG: Bacillus-Calmette-Guerin
- M. boris
- protects against TB-meningitis in children

Salk & Sabin:
- IPV (Salk, 1955) and OPV (Sabin, 1963)

Question 4

Explain herd immunity

Answer 4

idea that an entire community can be protected from an illness by immunising a certain percentage of individuals
- correlates with R-number
- pathogen specific

• hard to archive if virus mutates often (Influenza, SARS-CoV 2)

Question 5

What is serotype replacement?

Answer 5

the expansion of non-vaccine serotypes as as result of the removal of vaccine types from the population

Question 6

What immune response do successful vaccines induce?

Answer 6

Antibody dependent

needed:
- HIV -> T cells
- Malaria -> more T cells
- TB -> mainly T-cells

Question 7

Name the available/possible types of vaccines

Answer 7

Question 8

vaccine examples for each type

Answer 8

inactivated - Polio (Salk), Rabies
live attenuated - BCG, Mumps-Measles-Rubella
live vector - Ebola

subunit/split:
protein - Tetanus, Diphtheria
polysaccharide - pneumococci
conjugate - Salmonella, Meningococci, Pertussis/Keuchhusten

mRNA - SARS-CoV-2

Question 9

What are common vaccine components

Answer 9

• active ingredients (antigenic information)
• adjuvants (boost the immune reaction)
• antibiotics (prevent bacterial contamination)
• stabilisers (maintain vaccinestability and effectiveness during storage)
• trace components (components from manufacturing like culture material or inactivating agents)
• preservatives (prevent bacterial & fungal growth) -> only in multi dose vials of flu vaccine

Question 10

(Dis-)Advantages of live/attenuated vaccines

Answer 10

Advantages:
- immunogenic memory, immunstimalatory
- mucosal immunity
- persistence
- multivalent
- long experience

Disadvantages:
- inflammation
- revision -> infection -> safety
- recombination

Question 11

Name the three vaccine options in TB

Answer 11

• prophylactic -> BCG
• after exposure/latent TB
• therapeutic vaccination -> cure TB

Question 12

(Dis-)Advantages of recombinant protein vaccines

Answer 12

Advantages:
- safe, defined, stable
- correct conformation -> ABs

Disadvantages:
- low immunogenicity
- no CD8+ T cells

Question 13

(Dis-)Advantages of peptide vaccines

Answer 13

Advantages:
- safe, defined, stable
- cheap

Disadvantages:
- very low immunogenicity
- no CD8+ T cells
- no conformation -> no ABs

often used as protein-conjugates with toxoids: tetanospasmin, diphtheria, cholera

Question 14

How do mRNA vaccines work?

Answer 14

1. conventional mRNA:
   - mRNA with GOI, cap, 5‘-UTR, 3‘-UTR and polyAAAAAAA
   - translation leads to protein -> presented on host cell surface for AB induction, degraded parts on peptide-MHC
   a) uridine mRNA: strong AB response, CD8 > CD4, active at low doses
   b) nucleoside-modified mRNA: very strong AB response, CD4 > CD8
2. self-amplifying mRNA (not used)
   - mRNA with GOI +replicase, cap, 5‘-UTR, 3‘-UTR and polyAAAAAAA
   - translation leads to protein -> presented on host cell surface for AB induction, degraded parts on peptide-MHC but in higher amounts

Question 15

(Dis-)Advantages of adjuvants

Answer 15

Advantages:
- depot effect
- immune stimulation
- often used: virus-like particles, lipid A, toxoids, oil in water, liposomes

Disadvantages:
- inflammation -> actually wanted

Question 16

What makes a good adjuvant?

Answer 16

strong and equal activation of humoral (B cell) and cellular (T cell) immunity