vaccine therapies Flashcards
which vaccine therapy to describe
choose at least one
objectives
*Understand the need for vaccination in the general population
*What is a vaccine, why is herd immunity needed
*Prophylactic and therapeutic vaccines: what are the differences and what the applications of each
*Vaccine types: understand the difference between them, mechanism of action, advantages/limitations and remember some examples of each
*To be able to elaborate and discuss which vaccine type would be more fitting to target specific pathogens or cancer
*mRNA vaccines and cancer vaccines: to be able to describe the mechanism of action, limitations, challenges and future directions
what is vaccines
is a biological preparation that provide active acquires immunity to the infectious diseases
what are the classes of vaccine
prophylactic vaccine: to prevent future infection
therapeutic vaccine: to fight diseases that has already occurred like cancer
what are the purpose of vaccinnantion
- to prevent those who can’t be vaccinated
- to avoid/limit the spread of infectious diseases
what effect does vaccine has in our body
it stimulate protective immune response
what is Herd immunity
occurs when critical level of vaccination has been achieved
when does virus spread stop
when the probability of infection drop from the critical level
what does critical level depends on
virus and population specific
what is population % needed to achieve the herd immunity
80-85% for polio and 90-95% for measles ( highly contagious)
can vaccine be 100% effective
no
how many population have to be vaccinated to achieve 80% of critical level of infection
89% population
differentiate between prophylactic and therapeutic vaccine
prophylactic
-engage in immune system to fight off the diseases in the future
-provide protection against the pathogen by building immunity
ex: small pork, measles, polio, mRNA for HIV
therapeutic
- strengthen immune response to fight off the existing infection
-designed for treatment of cancer or infectious diseases
ex: cancer, HepB
what are the vaccine type
- Live attenuated vaccine
- mechanism of action: live, weakened or inactivated form of pathogen
- advantage: strong and long lasting immunity
-limitation: reverting to to pathogenic form, increase risk of infection for immunocompromised patients, new version can’t be developed rapidly - inactivated vaccine
-mechanism: non-living pathogen
- advantage: low possibility of side effect
- limitation: not strong as live attenuated vaccines, multiple booster shots are needed
3.outer membrane vesicle vaccine
- mechanism: OMVs are used to present antigen for vaccine
-advantage: least challenging as the antigen are present in the outer membrane
-challenge: issue with the consistency of yield, immunogenicity, and toxicity
- subunit (PURIFIED PROTEIN)
-mechanism: employs part of pathogen
-advantage: can be given to immunocompromised patients
-limitation: expensive, poor immunogenicity without adjuvants - Protein-polysaccharide conjugate vaccine
- mechanism: bacterial are coated with polysaccharides
-advantage: long term and high immunogenicity in young child
-challenges: carrier protein induce immune response to itself - HPV vaccines
7.Virus-like particle
- mechanism: mimic the organization and conformation of native virus but lack the viral genome
-advantage: non-infectious safe
-limitation: liquid formation which can pose issue of storage and safety - antigen presenting cell vaccine
- mechanism: generation of APCs by reprogramming of endogenous APC
- advantage: used for anti-tumour immunity
-limitation: immunosuppressive MTE - bacterial vector vaccine
-mechanism: use bacterial vector to deliver pathogen to stimulate host immune response . bacterial are modified with inactive pathogen components
-advantage: high immunogenicity, easy to manufacture, inexpensive
-limitation: neutralization antibodies restrict the effect, toxic - viral vector vaccine
mechanism: used to deliver harmless virus that encode for the antigen of pathogen
advantage: doesn’t require additional adjuvants, can be used for a wide range of infection
limitation: low effective, not suitable for immunocompromised patients - Nucleic acid vaccine (mRNA)
-mechanism: use genetic material to code for antigen protein
- advantage: effective against multiple infectious virus, no risk of causing diseases
-limitation: mRNA degrade quickly and is not stable, lead to unwanted immune response
is 90% of high-risk HPVs cause cancer
yes
describe Inactivated Influenza vaccine, its effective and challenge
vaccine is produced using non-living influenza virus growing in embryonated chicken eggs.
the virus is detergent-inactivated to prevent it from causing the infection while retaining its ability to stimulate the immune response.
effective: its 60% effective
challenges: envelope protein of influenza virus change every yearly so, it require annual up-data to the vaccine composition
describe DC vaccine
- isolate immature DC from peripheral blood
- generate immature DC by culture it with IL-4
- leads to mature/activated DC in the presence of tumour fragment
- re-infuse mature- tumour-specific DCs
describe mRNA vaccine and give one example
- mRNA is injected into the body
- ribosome translate mRNA into viral protein, then cells move protein to the outer surface of its membrane
- T cells recognize the viral protein lead to T cells activation
- then antibody production is initiated
example: SARS-CoV-2
what are the mRNA vaccines challenges and potential solution
1.
challenge:
-large mRNA pose risk of effective transportation into the host cells
solution:
-increase efficiency by adding adjuvants which create strong immune response
2.
challenge:
- currently delivery system due to lipid complex
solution:
- use polymer and lipid-polymer nanoparticle which increase safety, efficiency and lower cost
3.
challenge:
-inflammation due to impurities in the mRNA vaccine
solution:
- filtrate method to purify mRNA sample
is mRNA vaccine going to be used to treat HIV and influenza in future
yes
describe 2 classes of cancer vaccine
- prophylactic cancer vaccine: used to prevent viral infectious that can cause cancer
-therapeutic cancer vaccine:
*help immune system to recognize, target and eliminate cancer cells- don not eliminate the underlying cause of cancer
what is personalized cancer vaccine
prepared from autologous tumour cells
challenge: immunosuppressive TME
what are the future perspectives to consider in vaccine therapy
- identification of novel vaccine vector and antigen
- improve method of antigen delivery
- improve method for vaccine delivery
requirement for effective vaccine
-low cost
-safety: no diseases or side effect
-provide long lasting protection
-induce appropriate immune response
