Vaccinology - definitions, components, types of vax, dev't part 1 Flashcards
what are the two main means of immunization (2)
1- active
2- passive
what is active immunization (1)
making the body actively generate antibodies after vaccination - e.g. the process after any vaccine is given
compared to passive imm, how quickly do you get protected, and how long does protection from active immunization last - general terms (1)
takes longer to make antibodies but protection lasts longer
what is passive immunization (2)
1- giving the body pre-formed antibodies for immediate but temporary protection against a disease for around 1 month
2- includes trans placental transfer of antibodies from mom to baby (e.g. pertussis…you get Tdap vaccine in pregnancy)
why/when is passive immunization useful (2)
1- useful for when there’s isn’t a vaccine available, or vaccine is c/i
2- or if a susceptible individuals has been exposed to an infectious agent and requires immediate protection (e.g. PEP)
what are some examples of passive immunization (MVBART) (6)
Ig for:
1- measles
2- varicella
3- hep A
4- hep B
5- rabies
6- tetanus
what is immunity (2)
1- protection from an infectious disease
2- if you are immune to a disease, you can be exposed to it without becoming infected
what is vaccinology (1)
1- the science of vaccine development and how the immune system responds to vaccines
what is a vaccine (1)
1- a product that stimulates a person’s immune system to produce immunity to a specific disease, protecting the person from that disease
what are the 5 components of a vaccine (PAAAS) (5)
1- preservatives
2- antigen
3- additive
4- adjuvant
5- stabilizer
describe the preservative component of a vaccine and give an example (1 + 1)
1- preservatives: added to prevent fungal or bacterial contamination
2- e.g. thimerosal in multi-dose flu vax vials and hep B vax; e.g. formaldehyde, phenol
describe the adjuvant component of a vaccine and give an example (2 + 1)
1- adjuvant: added to enhance immune response to vaccine by extending duration of B and T cell responses
2- work to reduce the amount of antigen in a vaccine dose, and/or reduce the number of total doses needed to gain immunity
3- e.g. Aluminum salts, ASO4 (proprietary)
describe the antibiotic component of a vaccine and give an example (2 + 1)
1- antibiotic: residual from the manufacturing process to prevent bacterial contamination of culture cells
2- only trace amounts in vaccines
3- e.g. neomycin, streptomycin, polymyxin B)
describe the antigen component of a vaccine and give an example (2 + 1)
1- antigen: derived from disease-causing agent
2- is the component that the body will produce an immune response to (considered foreign by the body)
3- any antigen e.g. rabies virus, influenza virus
describe the stabilizer component of a vaccine and give an example (2 + 1)
1- stabilizers (additives): used to preserve potency
2- used to stabilize a vaccine against heat or freeze-dried conditions, against pH variation, against protein/carbohydrate aggregation or hydrolysis
3- e.g. MgSO4; gelatin; human serum albumin
what are the determinants of vaccine response - PACVHOTRI (9)
1- presence of adjuvant
2- antigen dose
3- carrier protein
4- vaccine type
5- host factors
6- other (route)
7- timing between doses
8- recipient age
9- immune system status
describe the ‘antigen dose’ determinant of vaccine response (1)
Antigen dose - higher dose (to a threshold) means higher immune response
describe the ‘conjugate/carrier protein’ determinant of vaccine response (1)
Carrier protein - antigen conjugated to a carrier protein that’s easily recognized by the body will lead to more robust immune response
describe the ‘vaccine type’ determinant of vaccine response (1)
Vaccine type - live attenuated has greater response than inactivated vaccine
describe the ‘host factors’ determinant of vaccine response (1)
Host factors - age, sex, comorbidities
describe the ‘timing between doses’ determinant of vaccine response (1)
Timing between doses - need sufficient time to build successive waves of B cell response to go from primary response (slow production of antibodies) to secondary response (rapid production of antibodies since memory B cells recognize antigen)
describe the ‘recipient age’ determinant of vaccine response (2)
1- recipient age: extremes of age have lower immune responses from vaccination
2- younger age = less mature immune system, less response; old age = lower response as well
describe the ‘immune system status’ determinant of vaccine response (1)
Immune system status: immunocompromised people have limited immune response
what are the qualities of an ideal vaccine “farmer Ed’s easy ass - Easy ASS E-I-E-E-D (5 + 4)
1- easy to administer
2- affordable
3- safe
4- stable
5- effective
5a- immunogenicity
5b- efficacy
5c- effectiveness
5d- duration of protection
describe the ‘easy to administer’ quality of an ideal vaccine (2)
1- Oral and intranasal = easier to administer than injectable
2- you only administer the minimum number of doses required
describe the ‘affordable’ quality of an ideal vaccine (2)
1- Older vaccines cost only a few dollars per dose, while newer vaccines can cost $60/dose
2- Competition brings the price down
describe the ‘safe’ quality of an ideal vaccine (3)
1- Common side effects are mild, serious side effects are rare
2- Does not cause disease
3- disease not transmissible to others
describe the ‘stable’ quality of an ideal vaccine (2)
1- Temperature (ideally doesn’t require cold-chain)
2- Long shelf-life
describe the ‘effective’ quality of an ideal vaccine (4)
1- Immunogenicity: induces antibodies in individuals
2- Efficacy: reduces disease in clinical trials
3- Effectiveness: reduces disease in real-world populations
4- Duration of protection: need for boosters is limited (no waning immunity)
what are the two main categories of vaccine types (2)
1- live-attenuated (Contain whole, weakened bacteria or virus)
2- non-live
what are pros of live-attenuated vaccines (2)
1- Strong immune response (immunity similar to natural infection)
2- Single dose may be sufficient
what are cons of live-attenuated vaccines (3)
1- Rare potential to revert to virulence (e.g., polio)
2- Contraindicated in pregnancy and immunocompromised people
3- Possible interaction with other live virus vaccines (4 weeks between doses)
what are examples of live vaccines - BYMR VPoL (7)
1- BCG
2- Yellow fever
3- MMR
4- rotavirus
5- varicella
6- oral polio
7- live attenuated influenza
what are the subtypes of non-live vaccines - SIT NV (5)
1- subunit-based
2- inactivated antigen
3- toxoid
4- nucleic acid
5- viral vector
what are the sub-subtypes of subunit-based vaccines - PCP (3)
1- protein-subunit
2- conjugate subunit
3- polysaccharide subunit
what is a protein-subunit vaccine (1)
1- it Presents an antigen to the immune system using an isolated protein of the pathogen
what are pros of protein subunit vaccines (1)
1- No live components so no risk of causing disease
what are cons of protein subunit vaccines (1)
1- If denatured, isolated proteins may bind to different antibodies than the protein of the pathogen
what are examples of protein subunit vaccines (1)
1- acellular pertussis (aP)
what is a conjugate subunit vaccine (1)
1- also uses the bacterial polysaccharide capsule, but adds
a conjugated carrier protein
what are pros of conjugate vaccines (2)
1- Can induce long-term immunity
2- induce immune response in infants
what are cons of conjugate vaccines (1)
1- more difficult to manufacture
what are some examples of conjugate vaccines (2)
1- Haemophilus influenzae type B (Hib) vaccine
2- Pneumococcal conjugate vaccine
what is a polysaccharide subunit vaccine (1)
How does a bacteria’s polysaccharide capsule relate to infecting young children (1)
1- uses the bacterial polysaccharide capsule as the antigen
2- some bacteria use a polysaccharide capsule to evade the immune system (this is particularly effective in young children)
What are some examples of encapsulated bacteria (7) - SHiNE SaSK
Streptococcus pneumonia
Hib (haemophilus influenzae)
Neisseria meningitidis
E Coli
Salmonella
GBS
Klebsiella
what are pros of polysaccharide vaccines (2)
1- No live components so no risk of causing disease
2- Induce short- term immunity
what are cons of polysaccharide vaccines (2)
1- Molecules are small and often not very immunogenic
2- May not induce long-term/durable immunity
what are examples of polysaccharide vaccines (2)
1- Meningococcal polysaccharide A,C,Y, W- 135 vaccine
2- Pneumococcal polysaccharide vaccines
what is an inactivated antigen vaccine (1)
1- Contains whole or parts of an inactivated agent
what are pros of inactivated antigen vaccines (3)
1- Stable
2- Unable to cause the infection
3- Can use in pregnancy
what are cons of inactivated antigen vaccines (3)
1- May require several doses/boosters
2- Adjuvant may be needed
3- Shorter lasting immunity
what are some examples of inactivated antigen vaccines - HaRIP (4)
1- hep A
2- rabies
3- influenza (non-live)
4- inactivated polio
what is a toxoid vaccine (1)
1- Uses a weakened toxin made by the agent that causes disease
what is a pro of toxoid vaccine (similar to general non-live vaccine pro) (1)
1- cannot cause disease
what are cons of toxoid vaccine (similar to general non-live vaccine cons) (2)
1- May require several doses/boosters
2- Adjuvant may be needed
what are examples of toxoid vaccine (1)
1- DTaP vaccine contains diphtheria and tetanus toxoids
what are sub-subtypes of nucleic acid vaccines - MR (2)
1- mRNA
2- recombinant
what is an mRNA vaccine (1)
1- uses viral mRNA to make proteins in a host body in order to trigger an immune response
what are pros of mRNA vaccines (1)
1- Shorter manufacturing times
what are cons of mRNA vaccines (1)
1- Require specialized cold shipping/storage conditions at -80 degC
what is an example of mRNA vaccine (1)
1- COVID-19 Vaccines
what is a recombinant vaccine (1)
1- allow vaccine proteins to be expressed by alternative cell types in controlled settings, including insect, plant, yeast, and mammalian cells (instead of eggs, for example) - these proteins are then used as antigens in vaccine
what are pros of recombinant vaccines (1)
1- No live components so no risk of causing disease
what are the cons of recombinant vaccines - general like non-live (1)
1- May not induce long-term immunity
what are examples of recombinant vaccines (2) - HH
1- Hepatitis B vaccine
2- HPV vaccine
what is a viral vector vaccine (1)
1- Use modified version of different, ‘harmless’ virus as vector for delivering antigen to host cells
what are pros of vector vaccines (1)
1- elicit strong immune response
what are cons of vector vaccines (different con to general non-live vaccines) (1)
1- Previous exposure to vector virus may reduce effectiveness of vaccine
what are examples of vector vaccines (1)
1- COVID-19 vaccine with adenovirus vector
who are key stakeholders in vaccine development & approval in Canada - HFN CPCP (7)
1- health canada - BRDD - biologics and radiopharmaceutical drugs directorate (second in process)
2- food and drugs act (first in process)
3- NACI - national advisory committee on immunization
4- CIC - canadian immunization committee
5- PHAC - public health agency of canada
6- CATMAT - committee to advise on tropical medicine and travel
7- PT - provinces and territories
describe ‘health canada’ as a key stakeholder for vaccine dev’t and approval in canada (3)
1- federal authority that reviews the clinical and manufacturing information of vaccine submissions
2- authorizes sale of vaccines that are safe, effective, of high quality, and whose benefits outweigh the risks
3- Also monitors vaccine safety and effectiveness
describe ‘food and drugs act’ as a key stakeholder for vaccine dev’t and approval in canada (2)
1- categorizes vaccines as biologic drugs
2- Requires special expertise and procedures for their manufacture, control, and regulation
describe ‘NACI’ as a key stakeholder for vaccine dev’t and approval in canada (3)
1- makes expert and evidence-based recommendations on vaccine use, strategy, research, programs
2- uses AFEEE for evaluating programs - acceptability, feasibility, ethics, equity, economics)
3- produces the Canadian immunization guide (CIG)
describe ‘CIC’ as a key stakeholder for vaccine dev’t and approval in canada (1)
1- reps from FPT who provide recommendations to Ministries of Health on vaccine program planning and policies, through PH network council
what are the working groups of CIC (4)
1- VSWG: vaccine safety
2- VVWG: vaccine vigilance
3- CIRC: CAN imm registry & coverage
4- NISWG: national immunization strategy working group (determines priorities, goals, targets)
describe ‘PHAC’ as a key stakeholder for vaccine dev’t and approval in canada (4)
1- Monitors vaccine safety via CAEFISS and IMPACT (peds)
2- Bulk procurement of publicly funded vaccines
3- Population vaccine coverage assessment
4- engages in imms awareness/promotion
describe ‘CATMAT’ as a key stakeholder for vaccine dev’t and approval in canada (2)
1- makes Recommendations re: tropical infectious diseases and health risks with international travel
2- generates travel health notices to help protect all Canadians upon travellers’ return to Canada
what are the levels of CATMAT travel health notices? (4)
1- Practice Usual Precautions (hand hygiene)
2- Practice Enhanced Precautions (vaccines if local outbreak)
3- Avoid non-essential travel (if large outbreak)
4- Avoid all travel
(there is risk of bringing back disease to Canada despite
precautions)
describe ‘PT’ as a key stakeholder for vaccine dev’t and approval in canada (5)
1- deliver immunization programs
2- set the imms schedules based on
jurisdictional context and NACI guidance
3- determine who/what circumstances are
the vaccines publicly funded
4- purchase vaccines for publicly funded
programs
5- maintain vaccine registries
what are the steps in vaccine development (6)
1- register
2- preclinical phase
3- phase 1
4- phase 2
5- phase 3
6- phase 4
describe the ‘register’ phase of the vaccine development process (1)
1- researchers/manufacturers need to register/submit an application for a clinical trial with BRDD at Health canada
describe the ‘preclinical’ phase of the vaccine development process (2)
lab/animal testing to see:
1- whether expected immune response is provoked;
2- whether there are any toxicities that would prevent use of candidate vaccine in humans
describe the ‘phase 1’ phase of the vaccine development process (3)
1- 10s of volunteers
2- is the vaccine safe?
3- does it provoke an immune response?
describe the ‘phase 2’ phase of the vaccine development process (3)
1- 100s of volunteers (target vaccinee group)
2- continue to check safety
3- determine best dose/schedule
describe the ‘phase 3’ phase of the vaccine development process (4)
1- 1000s of volunteers (variable group)
2- safety in larger groups
3- efficacy - does vaccine prevent disease
4- can submit to licensing after phase 3
describe the ‘phase 4’ phase of the vaccine development process (3)
1- post-licensing surveillance
2- assess real-world effectiveness
3- look for rare or unexpected adverse events
