9. Vaccines Flashcards
(61 cards)
What is the story of vaccination discovery?
Modern day vaccination: Dr Eward Jenner (end of 18th century) - noticed that milkmaids didn’t catch smallpox as easily - inoculated a boy with cowpox - developed immunity against smallpox => full protection againts smallpox
When was smallpox officially eradicated?
1980
What are the earliest records of vaccination?
- 7th century - Indian Budhists drank snake venom
- 10th century variolation to prevent smallpox in China, India, Turkey
What is the chronological sequence of vaccine type development?
- Bacterial vaccines
- Viral vaccines
- Molecular vaccines
What is passive immunisation?
Passive immunisation - transfer of serum antibodies - passive because the organism didn’t produce Ab itself
Who first developed passive immunisation?
Emil von Behring - Nobel prize in 1901 - developed passive immunisation for diphteria:
immunized guinea pigs against diphtheria with heat-treated blood products from animals recovered - antibodies to the diphtheria toxin - protected guinea pigs later exposed to lethal doses - next showed they could cure diphtheria in an animal by injecting it with the blood products of an immunized animal - Ab transfer
What are the modes of antibody transfer from immune to non-immune organism?
Passive immunity - Ab transfer:
1) Natural: transfer of mother’s Ab via placenta / mother milk (colostrum)
2) Artificial: Ab derived from blood of immune people / non-human immune animals
What is anti-sera?
Anti-sera / antisera / Ab serum - blood serum with antibodies against specific antigens, injected to treat or protect against specific diseases
- typically produced in donor animal (horse / sheep): animal immunised with non-lethal dose of antigen (toxin / venom / pathogen derived antigen) - blood from animal collected - Ab purified
What are the current aplications of Ab transfers?
Current Ab transfer applications:
- Rapid treatment: during acute ilness don’t need to wait for imm syst to develop
- Prevention measure: after transplantation
What are the adv and disadv of Ab transfer?
Ab transfer:
Adv:
- rapid acting
- support deficient immune system (beneficial to high-risk individuals)
Disadv:
- protection fades
- intravenous injection (instead of intramuscular)
- serum sickness - first time Ab recognised as Ag - imm response
- expensive / complicated to manufacture
What are monoclonal antibodies?
Monoclonal antibodies - A type of protein that is made in the laboratory and can bind to certain targets in the body - onse specific Ab for one Ag produced
Nobel prize 1984 Cesar Milsten, Georges J.F. Kohler
What was the initail method for monoclonal antibody production?
What are the major adv of monoclonal antibodies?
Adv of monoclonal antibodies:
- Single specificity (monoclonal)
- Unlimited supply (hybridomas can divide continously + can be frozen)
- Rare specificity Ab can be isolated
- Ab can be engineered - new specificieties, efficiencies
- more safe, less toxic in canceer threatment than chemotherapy
How are animal antibodies humanised?
Mouse monoclonal Ab can be recognised as Ag - use human Ab + adapt epitopes for Ag - add complementarity determining region (CDR) produced by mouse cells for the specific Ag (won’t be recognised as Ag) - Ag bound by the engineered Ab but not recognised as foreign because human Ab core is used
What are the currently used methods for monoclonal antibody production?
What do therapeutic monoclonal antibodies target?
- Cytokines
- Growth factor receptors
- Check point inhibitors
What are the main principles in vaccination?
- Introduce imm syst to a pathogen in a controlled env
- Cause imm syst to remember pathogen and respond to it
- Enable imm syst to effectively clear the pathogen to prevent disease
What are the characteristics sought in vaccines?
- long lasting immunity
- safe
- stable
- easy to store and administer
- single dose
- affordable
- pathogen evolution-proof
What are the features of adaptive immune system?
What are the main immune system components used in vaccination?
- Ab / B cells
- CD4 T cells
- CD8 T cells
What are the developed vaccines for polio?
Different types of vaccined developed for polio:
- Inactivated (whole pathogen killed): inactivated by formalin Jonas Salk
- Live-attenuated (weakened pathogen form): Albert Sabin
How are chicken eggs used for vaccine production?
Chicken eggs - vertebrate hosts for viral replication - different viruses grow in different egg parts - difficult host because need skilled professional to precisely inject the virus into a specific part + conditions for storage
What are the limitations of traditional vaccine production methods?
What are sub-unit vaccines?
Not entire organism - use components - ex proteins
Adv: no extra pathogenic particles (ex DNA)
Disadv: proteins may differ when outside the organism; production expensive
