Vaccination Flashcards
What is the purpose of vaccination?
disease prevention = for individual and community
prevention of common diseases or prevent spread of outbreaks
passive prevention of disease
maternal antibodies (placental transfer, breastmilk), antitoxins (tetanus fo ex), IVIg (specific and broad)
active prevention of disease
natural infection
vaccines
toxoids
T or F. Passive immunity can be artificial or natural
T
characteristics of a good vaccine
- effective = elicit correct response for the organism
- safe = minimal side effects; no disease
- inexpensive
- long term protection
- manufactured quickly
- easy to administer (1 dose, no refrigeration)
immune response required for viruses
cell-mediated
- cytotoxic T cells
- Th1, IL-2, IFNy, TNF
antibody
- can aid in prevention and spread of virus
- neutralization (bind surface to prevent attachment)
- complement activation
describe the antibody-mediated response to extracell bacteria
- toxin neutralization
- complement-mediated lysis
- opsonization and phagocytosis (Ig + Comp)
- anaphylatoxin = mast cell degranulation
- chemotaxis
define efficacy
ability of vaccine to elicit a response
measured in the individual (Ab level)
clinical trials
define effectiveness
ability of vaccine to reduce disease in the community
IMPACT
- Immunization monitoring program ACTive)
- across Canada
- pediatric hospital-based surveillance network
CAEFISS
Canadian adverse events following immunization surveillance system
- national monitoring (PHAC)
vaccine complications
- adverse rxns
- vaccine additives - allergens
> egg protein, latex, gelatin
> neomycin, streptomycin, gentamycin, polymyxin
> thimerosal
inactivated vaccine
- killed by heat, chemical, irradiation
- stable
- humoral response
- side effects
- requires boosters (need to see Ag over and over to get plasma cells to produce memory B cells)
whole organism vaccines
bacteria or viral particles
inactivated
live attenuated
live attenuated
- same parent organism, just not pathogenic (avirulent strain)
- good efficacy (one repeat)
- poor stability (needs refrigeration)
- humoral and cell-mediated response
- few side effects
- may revert to virulent form
- immunosuppressed/immunocompromised
subunit vaccine
- component of organism used (purified macromolecule)
- fewer side effects
- polysaccharide requires conjugate
- many capsular polysaccharide strains
types of subunit vaccine
inactivated exotoxin (toxoid)
polysaccharide
recombinant microbial antigen
this outlines policy and regulations regarding publicly funded immunizations
Alberta Immunization Policy
- Alberta Ministry of Health
- Provincial Legislation (Public Health)
these governing bodies ensure access, safety, education, training, reporting, research, and evaluation
CMOH with government and AHS
DTaP-IPV-Hib-HB
DIPHTHERIA, TETANUS, ACELLULAR PERTUSSIS
INACTIVATED POLIO VIRUS
HAEMOPHILUS INFLUENZAE TYPE B
HEP B
how often do you get a tetanus shot as an adult?
every ten years
HiB
Haemophilus influenzae type B
- encapsulated = phagocytosis and complement resistant
- bacteremia, pneumonia, epiglottitis, meningitis
- most common cause of bacterial meningitis in children under 5 prior to vaccine
- conjugate vaccine
T or F. HiB vaccine is a polysaccharide vaccine
T!
Disadvantages of HiB polysaccharide vaccine
- no memory
- IgM response only
- T-independent
- does not work in children under 2 y/o
pneumococcal disease
- S. pneumoniae
- pneumonia, sepsis, meningitis
- multiple strains/serotypes
- polysaccharide
- vaccine must be conjugated and include serotypes causing disease
- polysaccharide vaccines ineffective in children under 2
- PNEU-C13
rotavirus route of admission
fecal-oral route
risk group: 3 months - 3 yrs
symptoms of rotavirus
fever, vomiting, severe diarrhea
this can cause severe dehydration/hospitalization
rotavirus
T or F. Rotorix is available for risk groups only
F! Available for everyone in AB; oral vaccine
what type of vaccine is Rotorix?
live attenuated virus
- lots of side effects = GI upset
- leads parents not to get second dose
MMR-Var
- live attenuated
- 95% effective at one dose; 2 doses = 100%
- less effective before 6 mos of age
- 12-18 mos - 4 yrs if only one dose
side effects of MMR-Var
mild fever, rash that can look like disease
rare but serious side effects of measles
encephalitis
rare but serious side effects of mumps
sterility, deafness, encephalitis
rare but serious side effects of rubella in pregnancy
miscarriage, deafness
complications of chickenpox
CELLULITIS, GROUP A STREP, PNEUMONIA, ENCEPHALITIS
Shingles
reactivation of virus as an adult
= painful, time off work, $
N. meningitidis
meningococcal disease
- septicemia, meningitis
- risk groups: children <2, 15-24 elderly
- conjugate vaccine (MenCC); 4-24 mos
> protection vs type C
- gr 9 = ACYW-135 = teens, young adults = close contact, dorms, etc.
T or F. HPV self-resolves
T
cancers caused by HPV
cervical, anal, vaginal, penile, head, and neck
when is the HPV vaccine administered?
grade 6 = males and females
strains of HPV
9
HPV-9
non-routine vaccines purpose
travel
occupation
high risk group = lifestyle, health
group living facility
must pay/not free
Hep A vaccine
Havrix = 1 dose = inactivated virus
Twinrix = 3 doses HAV inact/HBV recomb
Hep A route of admission
fecal/oral
non-endemic to Canada
high-risk for Hep A
travel to endemic areas
military
occupational workers
liver disease
high risk sexual behaviour
Hepatitis B DNA
positive for virus and infectious
Hepatitis B HBs Ag
positive for virus - early stage
Hepatitis B Anti-HBs
end-stage of infection and immunity
Anti-HBc
previous or chronic infection
- Anti-HBc IgM/Total (see if really chronic or right afer infection)
HBe (enveloped) Ag and anti-HBe
chronic infection
HBV vaccine - we are positive for this
HBs Ag
what kind of vaccine is HBV vaccine
recombinant subuit
this titre for anti-HBs is considred protective
> /= 10 IU/L
Dukoral
V. cholerae
- inactivated Vibrio strains (heat/formalin)
- recombinant cholera B toxin subunit
- oral = IgA production
= also provides protection to TEC
T or F. Labile toxin for Vibrio and ETEC are similar
T, antibody response will neutralize
T or F. Dukoral is self-administered
T
how many doses for Dukoral
2 doses 1 wk apart prior to travel
limitations of Dukoral
- traveller’s diarrhea can be caused by other organisms
- side effects = 50% ab pain, diarrhea
- requires boosters
at risk populations that require vaccines
transplantation workup
splenectomy pt
pregnancy
senior in long term care
why are live attenuated vaccines not recommended for children under 12 mos
less effective de to passive maternal immunity
why are live attenuated viruses not recommended for immunosuppressed individuals?
virus might be strong enough to cause disease
this vaccine leads to long lasting, effective immunity (cellular, humoral) with often 1 dose
live attenuated virus
two doses almost 100% protection
this vaccine requires refrigeration
live attenuated
- short expiry to ensure viability
T or F. Live attenuated virus vaccines may have more pronounced side effects such as fever, rash, respiratory due to live virus
T
inactivated virus vaccines characteristics
safe, effective, minimal side effects
produce humoral response rather than cellular response
may require multiple doses
conjugate, subunit recomb, toxoid vaccines characteristic(s)
- strong humoral responses to specific aspects of pathogen (cell wall, protein, etc.)
- requires multiple doses and booster shots
- toxoid provides protection against toxin, and not the organism itself
AstraZeneca vs J&J DNA COVID vaccine
- modified non-replicating chimp adenovirus
- E1 gene replaced with Covid19 spike gene (J&J Ad26.COV2)
- similar = only human adenovirus vs. chimp)
side effects of AstraZeneca vaccines
- rare but serious
- vaccine-induced immune thrombotic thrombocytopenia (VITT)
- antibodies produced against PF4
- incidence 0.000019
COVID mRNA vaccines
Pfizer and Moderna
how do mRNA vaccines work?
- mRNA encapsulated in lipid nanoparticle fuse with cells
- mRNA produces spike protein
- MHC I presentation
- secreted antigen taken up by macs = MHC II presentation
- TLR 3 = RNA
safety and effectiveness of Pfizer and Moderna
95% EFFICACY AFTER TWO DOSES = PHASE 3 TRIALS
side effects of Pfizer
- pain, swelling, fatigue (mild-moderate)
- 1-3 day duration
- rare myocarditis in males 12-17 y/o
T or F. Polysaccharide vaccines are not effective in children under 2 years of age
T! unless conjugated
pure polysaccharide vaccines - why are they not recommended?
only T indenpdent immunity = no memory, lss specific, IgM only
short-lived (~2 yrs)
targets specific strains only
pros of DNA vaccibues
- induces cell mediated immunity
- prolongs expression, enhances memory
AstraZeneca vaccine
- non-replicating virus enters cell
- cDNA into nucleus => mRNA
- spike proteins produced
- MHC I display
- secreted antigen taken up by macs (MHC II)
- cellular and humoral
- TLR 9
