2: Vaccine Basics Flashcards
How does immune response occur?
- patient’s immune system recognize/identify antigens
- immune response: develop specific antibodies (IG) against antigen
- memory created (B cells) and some circulate
- production of antibodies; natural IG, upon re-exposure to angigen
What are the two types of immunity?
Passive - immediate protection, short term protection, derived from other sources
active - delayed protection, long term effects, person immune system produces protection
Examples of passive immunity.
- immune globulins (IG) and blood products (maternal IG, rabies IG, Hep A)
- antitoxin (diptheria antitoxin (DAT))
- monoclonal antibodies (palicizumab)
What are some factors that affect immune response?
Factors affecting the host: passively acquired antibody, age, nutrition, genetics.
Factors affecting vaccine: type of vaccine, dose, route, presence of adjuvant.
Vaccine quality of immune response: greatest to least
- live virus/bacteria
- easily recognizable surface proteins
- pure polysaccharide
How are vaccines classified?
Live and inactivated vaccines
What is a live vaccine?
adjuvanted virus or bacteria
What is an inactivated vaccine?
- whole virus/bacteria
- part or whole protein (e.g toxoid, subunit, recombinant, polysaccharide)
How do live vaccines work?
- first does provides protection
- second dose provides protection for small percentage of patients that did not respond to first dose
What are some important considerations for live vaccines?
- storage, circulating antibody, vaccine timing
What are adverse reactions to live vaccines?
- mild disease in heathy patients
- should be AVOIDED in patients with immunodeficiencies, or other specific conditions
- serious adverse reactions possible
Characteristics of inactivated vaccines
- first dose is a “priming” dose
- protection expected after 2-3 doses
- efficacy decreases after a few years (boosters provide continued protection)
Vaccine timing: increased spacing vs. decreased spacing
Increased spacing (months/years) between vaccine doses, does not interfere with effectiveness (no need to restart schedule)
decreased spacing (days or weeks) between scheduled doses of vaccines, can decrease antibody response and potentially effectiveness.
True or false: live vaccines cannot be given together.
False. live vaccines need to be given on the same clinic day or seperated by 28 days.
If given too close to eachother, the 2nd dose will need to re-administered or evaluated.
What are the exceptions to the simultaneous vaccine recommendations?
- PCV13 and Menactra vaccine should not be administered at the same time to anyone with asplenia or HIV.
- NONE of the pneumococcal conjugate vaccines (PCV13, PCV15, PCV20) should be administered with PPSV23.
- varicella vaccine should NOT be administered simultaneously with smallpox vaccine
What are combination vaccines?
Vaccines that include antigens indicated for the patient based on age and condition.
Define adverse reaction (ADR) versus adverse event (ADE)
adverse reaction - reactions caused by disease; side effects
adverse events - any medical event that occurs after vaccination
Clinically significant adverse events should be reported to….
VAERS
Define contraindication
should NOT recieve the vaccine
Define precaution
risk vs benefit
(most times the vaccine can deferred until the patient no longer has the condition then vaccinate)
Adverse events: A health-care provider is REQUIRED to report:
- any event listed by the vaccine manufacturer as a contraindication to subsequent doses of the vaccine.
- any event listed in the reportable events table that occurs within the specified time period after vaccination.
What are some common precautions/contraindications?
allergies, pregnancy, immunosuppression, acute illness (moderate-severe)
Special considerations for pregnancy patients
- can receive most inactivated vaccines
- cannot receive live vaccines, HPV, MenB, and non-aluminum adjuvanted vaccines (close contacts can)
Considerations for immunosuppression
Inactivated vaccines: okay to administer, may have reduced response.
Live vaccine: DO NOT administer, could result severe reactions.
Considerations for patients with HIV
vaccinate: inactive vaccines, MMR (if asymptomatic), varicella (asymptomatic children)
DO NOT vaccinate: LAIV, rotavirus, MMRV
How does a stem cell transplant affect vaccine immunity?
- antibody titers decline 1-4 years after SCT
- patients should revaccinate with most inactivated vaccines 6 months after SCT
Do antibootics affect vaccinations?
- routines are not affected
- oral typhoid vaccine replication is affected
