What should be contained within a vaccine?
- Antigen
- Immune stimulatory agent
- Preservative, stabilisers
What biological molecule do vaccines contain?
Proteins
What is the purpose of vaccines?
Prime the adaptive immune system to the antigens of a particular microbe so that a rapid and effective response is generated on contact with the organism or its products
→ Prevention of disease
List 5 features of an effective vaccine
- Safe
- Protective
- Sustained protection
- Induce an appropriate immune response
- Practical considerations - cost, stability, ease of administration, side effects
What are the 2 main classes of therapeutic protein?
- Proteins and peptides
- Monoclonal antibodies
→ Both are polypeptides
How are therapeutic proteins and peptides used?
Selected for the closest replacement to endogenous proteins
What are therapeutic monoclonal antibodies?
Antibodies made artifically outside of the body then delivered to the patient
How are therapeutic monoclonal antibodies used?
- Have the ability to bind to any antigen target
- Range of effects - blocking, bindong, activating, killing
Give 3 examples of proteins and peptides that are used therapeutically
- Insulin
- Growth hormone
- Cloting/blood factors
List 2 examples of how monoclonal antibodies are used therapeutically
- Herceptin - used to treat some cancers
- Infliximab - autoimmune diseases e.g. Chron’s
List the 3 vaccine types and some examples of the infections they protect against
- Live attenuated - Poilo, BCG (TB), Typhoid fever
- Inactivated (killed) - Influenza
- Sub-unit - Hep. B, Tetanus toxin
List the 4 components of a vaccine
- Antigen - whole organism or its protein/polysaccharide
- Adjuvant - aluminium salts or gels
- Stabilisers - e.g. polysorbates
- Preservative - e.g. thimerosal/formaldehyde
What is the purpose of the antigen in a vaccine?
Generates immune response to protect from future infection
What is the purpose of an adjuvant in a vaccine?
- Helps create a stronger immune response in the body - i.e. helps vaccine work better
- Often required for vaccines containing only the pathogen’s protein
What is the purpose of stabilisers in a vaccine
Prevents physical or chemical degradation of antigen
What is the purpose of a preservative in a vaccine?
Prevents microbial growth
How are vaccines delivered?
Usually intramuscular injection
Why do most vaccines have to be delivered via intramusclar injection?
- Vaccine will drain into the lymph nodes
- Immune responses occur in lymph nodes - T cells, B cells and dendritic cells are found here - site of action
Why can vaccines not be delivered orally?
Vaccines made of protein - will just be digested and have no therapeutic effect
List 4 formulation challenges for vaccines
- Stability
- Mechanism of action can be unclear
- Vaccines are not engineered - just developed my experiment
- Multiple doses often needed
What are 2 possible formulations for vaccines in the future?
- Microneedle patches
- Oral vaccines
What are microneedle patch vaccinations?
- Avoids penetrating dermis - painless
- Simple administration
- Needles can be pre-loaded with or manufactured from dried vaccine
- Delivery to tissue site rich with immune cells