What is Active Immunity
Immunity produced by one's OWN immune system. (After infection/vaccination). Lasts for years-lifetime
What is Passive Immunity
Immunity TRANSFERRED onto oneself from products/another. Temporary
1) Transplacental passive immunity from mothers - will protect up to 1 year for fully immunised mothers.
2) Homologous IV IG (post exposure prophylaxis hep A/measles, hep B, rabies, tetanus, varicella) [Homologous - from humans]
3) Heterologous IV IG (from animal, horse). Anti-toxin for diptheria, tetanus
4) Monoclonal Antibody - Derived from a single type, or clone, of antibody-producing cells (B cells). Antibody is specific to a single antigen or closely related group of antigens
What is an Antigen
A live OR inactivated substance capable of producing an immune reaction.
What is an Antibody
Protein molecules (immunoglobulins) producced by B lymphocytes to help ELIMINATE an antigen
What are the different types of vaccine
1) Life attenuated - lab modified disease producing virus/bacteria. ("Attenuated" = weakened)
- immune response produced almost identical to that of a "wild" type of virus/bacteria. CELLULAR mediated, memory B cells dev, and will kick in when exposed
- can be damaged by heat/light
2) Inactivated - whole or fractions of virus/bacteria. DEAD = cannot replicate, cannot cause disease EVEN IN IMMUNOCOMPROMISED.
- ALWAYS require MULTIPLE dose.
- immune response to an inactivated vaccine is mostly humoral w little to no cellular immunity. Antibody titers against inactivated antigens diminish with time.
- May need BOOSTERS
What are some examples of live-attenuated vaccines?
Viral: Measles, Mumps, Rubella, Varicella, zoster, vaccinia, yellow fever, rotavirus, intranasal influenza.
Bacteria: BCG, Oral thyphoid vaccine
What are some examples of inactivated vaccines
Viral
- Hep A, Hep B, polio, rabies
- Influenza
- HPV
- diptheria, thyphoid toxoids
Bacteria
- Pertussis, thyphoid
Pure polysaccharide vaccines: pneumococcal disease, meningococcal disease, and Salmonella Typhi
Alternative classification
1) whole cell
2) Fractionated
3) Polysaccharide
4) Recombinant (small parts of multiple organism genes) like influenza, HPV on a carrier cell (yeast or virus)
What are some important elements of polysacharride vaccines.
1) Repeat booster doses does NOT cause a booster antiboty response
2) Children <2yrs respond unpredictably to polysaccharide vaccines
3) Less functional antibody activity than that induced by protein antigens -because the predominant antibody produced in response to most polysaccharide vaccines is IgM, and little IgG is produced
CONJUGATION solves the above problems to some extent - olysaccharide is chemically combined with a protein molecule. it changes the immune response to a T cell dependent one.
What are some important considerations of administering body a vaccine and an antibody?
1) Presence of circulating antibody to a vaccine antigen may reduce or completely eliminate the immune response to the vaccine - this is NOT the case for most inactivated antigens.
ie simultaneous admin of post exposure Vaccine and IV IG for tetanus, hep B, rabies is OKAY.
For live vaccines, time between giving IV Ig and vaccine is always 3mths or longer.
What post-partum vaccines should be considered?
Women without evidence of immunity to rubella or varicella should receive MMR or varicella vaccine (but not MMRV) in the postpartum period
Can vaccines be co-administered?
1) General Rule: All vaccines can be administered at the same visit as all other vaccines.
2) **exception: in children with functional or anatomic asplenia pneumococcal conjugate vaccine (PCV13) and Menactra brand meningococcal conjugate vaccines should not be administered at the same visit; PCV first then Menectra at least 4 weeks
3) ***Note: Never mix vaccines into same syringe.
4) Try not to co-administer injected/intranasal vaccines at the same time.
5) Oral live vaccines are NOT thought to interfere w each other
Why is it preferred to give MMR and Varicella as separate vaccines for children (Despite availability or MMRV?)
Due to increased risk of febrile seizures following the first dose of MMRV vaccine compared to MMR and varicella vaccines.
What is important about Vaccine intervals/Ages?
1) Vaccine doses should not be administered at intervals less than the recommended minimal intervals or earlier than the minimal ages.
BUT
- children may receive MMR vacccine 6-11mths during outbreak/for travel purposes. However this WILL NOT count towards their vaccine schedule.
2) Vaccine doses administered up to 4 days before the minimum interval or age can be counted as valid (if risk of no follow up is more than of follow up) - Except Rabies vaccine.
What are some examples of inactivated vaccines whose immunity wanes and booster needs to be considered.
Tetanus, Pertussis, Diptheria, hep A
What Live attenuated vaccine is prone to causing systemic reactions.
DTP (which contains whole cell pertussis component).
In general systemic reactions are due to the live-attenuated vaccines replicating (in order to achieve immune rxn). May have mild form of dz
What are some notable vaccine related conditions for childhood vaccinations?
1) Intussusception related to rotavirus vaccine (rotavirus vaccine contraindicated if there is hx of intuss)
2) Encephalopathy not due to other cause related to pertussis vaccine (within 7 days of)
3) DTaP high fever/seizure/hypotonic state within 48hrs
What are some contrainidcations to vaccinations
1) Live attenuated: Pregnancy, immunosuppresion
2) All vaccines: moderate-severe illness. Receipt of antibody containing blood pdt.
What are some egg containing vaccines?
1) Yellow fever
2) Influenza Vaccines
What food allergy can predispose to MMR allergic reaction
gelatin
What vaccinations should be avoided in Pregnant Women?
1) small pox
2) ALL live vaccines
3) HPV vaccination (to be deferred)
** Long live vaccines when given, patients should be counselled to practice safe sex 1/12: Sexually active young women who receive MMR or varicella vaccination
What vaccinations are RECOMMENDED to be given DURING pregnancy
1) INACTIVATED influenza vaccine
2) Tdap vaccine regardless of prior vaccination (optimal between 27-36wks)
What are some considerations for vaccinations in immunosuppressed individuals:
1) Cannot received live attenuated vaccines (risk of transmission to fetus)
2) Can receive inactivated vaccines but immune response to vaccination may be reduced
3) For those who have completed chemotherapy/umminomodulator drugs - live vaccines CAN be given approx 3mths after last dose of chemo. (TNF-alpha blockers etc as well)
4) LT high dose steroids, should avoid live vaccines as well.
Are antibiotics/antivirals a contraindication to giving vaccination?
no CI for abx but should not give viral vaccinations until 48hrs after last dose antiviral
Any vaccines to omit for breastfeeding mothers?
Yellow fever vaccine.
What is important about the Varicella Vaccine?
1) not to be givne in pregnancy
2) not to be given in immunocompromised - needs to be evaluated first
What are some contraindications for further pertussis vaccine doses
1) Precautions to DTaP (not Tdap) include
(a) seizure within 3 days of a dose
(b) pale or limp episode or collapse within 48 hours of a dose
(c) continuous crying for 3 hours within 48 hours of a dose
(d) fever of 105°F (40°C) or higher within 48 hours of a previous dose
2) Encephalopathy within 7 days of a pertussis dose
3) unstable progressive neurologic problem (if stable problem, like seizure, can still give)
What vaccinations does a hx of Guillian barre Syndrome contrainidcate?
1) Influenza Vaccines
2) Tetanus containing vaccines
What is a CI for MMRV (combi one only) not includin separate MMR and V vaccines
Personal/fam hx of febrile/afebrile seizures