Vaccines & vaccination programs Flashcards
Is there a vaccination against S. pyogenes?
Why/ why not?
No effective vaccines
Explanations:
- lack of interest due to penicillin efficacy
- too many serotypes
- capsule: is poor immunogen
- M protein: immune response cross reacts with human tissue
Is there a vaccination against S.pneumoniae?
Yes, available and in use
- based on capsular polysaccharides
- active against common serotypes
- Prevnar: 7-valent pneumococcal conjugate vaccine (7vPCV)
- Prevnar 13®: 13-valent pneumococcal conjugate vaccine 13vPCV
- Pneumovax 23: 23-valent Pneumococcal polysaccharide vaccine (23vPPV)
Which pathogens have live attenuated vaccines available?
- Influenza (intranasal)
- MMR
- VZV
- Rotavirus
- Yellow fever
- Small pox
- Polio virus (Sabin)
Which pathogens have killed-pathogen vaccines available?
- Influenza (injected)
- HAV
- Rabies
- Polio (Salk)
Which pathogens have subunit vaccines available?
- HBV (HBsAg)
- HPV (6, 11, 16, 18)
- …
Which vaccines are available for H.influenzae in Canada?
INFANRIX hexa
- Conjugated HiB (w tetanus toxoid)
- DTaP + polio + HepB
PEDIACEL
- Conjugated HiB (w tetanus toxoid)
- DTaP + polio (no HepB)
Which vaccines are available for N.meningitidis in Canada?
Menjugate
- 1-valent conjugate
- Oligosacch from group C conj to CRM197
Menactra
- 4-valent conjugate
- Polysaccharides from A,C,Y,W conjugated to DT protein
What vaccines are available for S.pneumoniae?
Prevnar13 (PCV13)
- Conjugate vaccine
- Recomm <2y, >=65
PneumoVax23 (PPSV23)
- Polysacch vaccine
- Recomm >=65
At what ages do we vaccinate against diphtheria?
- 2m
- 4m
- 6m
- 18m
- 4y
- 15y
- Boosters q10y
- Pregnancy
At what ages do we vaccinate against tetanus?
- 2m
- 4m
- 6m
- 18m
- 4y
- 15y
- Boosters q10y
- Pregnancy
At what ages do we vaccinate against pertussis?
- 2m
- 4m
- 6m
- 18m
- 4y
- 15y
- Pregnancy
(No boosters, otherwise same as D+T)
At what ages do we vaccinate against polio?
- 2m
- 4m
- 6m
- 18m
- 4y
(Same as early schedule for DPT)
At what ages do we vaccinate against HiB?
- 2m
- 4m
- 6m
- 18m
(= Same Infant schedule as DTP-IPV)
At what ages do we vaccinate against Hepatitis B?
- 2m
- 4m
- 6m
- Boosters as needed
At what ages do we vaccinate against S.pneumo?
- 2m
- 4m
- 18m
- >= 65y
At what ages do we vaccinate against N.meningitidis?
- 12m
- 15y (ACYW)
At what ages do we vaccinate against MMR?
- 12m
- 4y
- Boosters as needed
At what ages do we vaccinate against Rotavirus?
- 2m
- 4m
- 6m
At what ages do we vaccinate against VZV?
- 12m
- >=65
At what ages do we vaccinate against HPV?
- 12y (x2 doses)
- 15y (x3 doses, girls only) {}
What types of vaccines are: Diphtheria & Tetanus vaccines
Toxin/toxoid
What type of vaccine is the IPV vaccine?
Inactivated
What type of vaccines are: Rotavirus, MMR, VZV
Live attenuated
What kind of vaccines are: S.pneumo, N.meningitidis MenC, MenACYW, and HiB?
Why?
Conjugate of bacterial polysaccharide to CRM197.
(HiB is to Tetanus toxoid)
{}
What kind of vaccine is: HBV, HPV, Pertussis
Subunit
Which pathogens are covered by routine childhood immunization in Canada?
Starting at which ages?
Starting at 2mo:
- DTaP + polio + HiB + HBV
- Rotavirus
- Pneumococcus (PneuC-13)
Starting at 4mo:
- Meningococcus (MenconC)
Starting at 6mo:
- Influenza
Starting at 1y:
- MMRV
Starting at 12y (Grade 6):
- HPV
Starting at 15y (Grade 9):
- Meningococcus (MenC-ACYW)
Which VPDs require booster shots? When?
Diphtheria & Tetanus
- Td = q10y
- dTap = 1 dose as an adult + 1 dose in every pregnancy
As needed & if at-risk: HBV, Rubella
(Influenza isn’t really a booster shot, but annual/repeated vaccination is recommended)
Which pathogens require adult immunization?
Pneumococcus (Pneumo-P= 1 dose ~=65yo)
Shingles, if prior VZV infection
Which pathogens’ vaccines are contraindicated for those who are immune compromised?
Live vaccines for:
- MMRV
- Rotavirus
- Varicella
- Shingles
- Influenza (but inactivated available)
… if traveling:
- YFV
- Cholera (but inactivated available)
- S.Typhi (but inactivated available)
… if risk:
- Smallpox
Which pathogens’ vaccines will not be effective in children <2 years old?
Why?
Unconjugated polysaccharide-based vaccines are not effective in infants <2.
- E.g. Pneumococcal PSP23 vaccine for seniors, not kids.
- Infants are able to mount good B cell-driven responses, but their T cell-based responses aren’t fully developed until ~2yo.
- In the meantime, they rely on aT cell-independent pathway.
- B cells recognize whole/unprocessed polysaccharide antigens and develop a weak, short, IgM-based response.
- But because Thelper cells don’t help B cells switch Ab classes, it never switches to IgG (for memory).
(In contrast, protein antigens are presented to CD4 T cells on MHC-II molecules. Conjugate vaccines activate both B and T cells. Immunologic memory should be lifelong.)
What is the difference between the different diphtheria/tetanus/pertussis vaccine formulations? {}
DTaP-IPV-Hib-HB
DTaP-IPV-Hib
dTap-IPV
dTap
Td
= +/- polio, +/- HiB, +/- hepatitis B virus
and
= Tdap is used to boost immunity for ~10yo (lower dose of diphtheria toxoid).
What are the pros & cons of live attenuated vaccines?
PROS:
- Induce both humoral and cell-mediated immunity.
- No booster needed
CONS:
- Dangerous to immunocompromised or their close contacts.
- Have reverted to virulence on rare occasion.
What are the pros & cons of killed-pathogen vaccines?
PROS:
- Easier production.
CONS:
- Induce humoral immunity only.
- Require boosters.
When are children routinely vaccinated for H.influenzae in Canada?
INFANRIX hexa
- @ 2+4+6 mo
PEDIACEL
- @ 18mo
When are children routinely vaccinated for N.meningitidis in Canada?
MenC
- @ 4 + 12mo
MenACYW
- @ Grade 9
What is the TB vaccine?
Bacille Calmette-Guerin (BCG): a live attenuated M.bovis strain
