2: Vaccine Basics

Question 1

How does immune response occur?

Answer 1

• 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

Question 2

What are the two types of immunity?

Answer 2

Passive - immediate protection, short term protection, derived from other sources
active - delayed protection, long term effects, person immune system produces protection

Question 3

Examples of passive immunity.

Answer 3

• immune globulins (IG) and blood products (maternal IG, rabies IG, Hep A)
• antitoxin (diptheria antitoxin (DAT))
• monoclonal antibodies (palicizumab)

Question 4

What are some factors that affect immune response?

Answer 4

Factors affecting the host: passively acquired antibody, age, nutrition, genetics.

Factors affecting vaccine: type of vaccine, dose, route, presence of adjuvant.

Question 5

Vaccine quality of immune response: greatest to least

Answer 5

1. live virus/bacteria
2. easily recognizable surface proteins
3. pure polysaccharide

Question 6

How are vaccines classified?

Answer 6

Live and inactivated vaccines

Question 7

What is a live vaccine?

Answer 7

adjuvanted virus or bacteria

Question 8

What is an inactivated vaccine?

Answer 8

• whole virus/bacteria
• part or whole protein (e.g toxoid, subunit, recombinant, polysaccharide)

Question 9

How do live vaccines work?

Answer 9

• first does provides protection
• second dose provides protection for small percentage of patients that did not respond to first dose

Question 10

What are some important considerations for live vaccines?

Answer 10

• storage, circulating antibody, vaccine timing

Question 11

What are adverse reactions to live vaccines?

Answer 11

• mild disease in heathy patients
• should be AVOIDED in patients with immunodeficiencies, or other specific conditions
• serious adverse reactions possible

Question 12

Characteristics of inactivated vaccines

Answer 12

• first dose is a “priming” dose
• protection expected after 2-3 doses
• efficacy decreases after a few years (boosters provide continued protection)

Question 13

Vaccine timing: increased spacing vs. decreased spacing

Answer 13

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.

Question 14

True or false: live vaccines cannot be given together.

Answer 14

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.

Question 15

What are the exceptions to the simultaneous vaccine recommendations?

Answer 15

• 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

Question 16

What are combination vaccines?

Answer 16

Vaccines that include antigens indicated for the patient based on age and condition.

Question 17

Define adverse reaction (ADR) versus adverse event (ADE)

Answer 17

adverse reaction - reactions caused by disease; side effects
adverse events - any medical event that occurs after vaccination

Question 18

Clinically significant adverse events should be reported to….

Answer 18

VAERS

Question 19

Define contraindication

Answer 19

should NOT recieve the vaccine

Question 20

Define precaution

Answer 20

risk vs benefit
(most times the vaccine can deferred until the patient no longer has the condition then vaccinate)

Question 21

Adverse events: A health-care provider is REQUIRED to report:

Answer 21

1. any event listed by the vaccine manufacturer as a contraindication to subsequent doses of the vaccine.
2. any event listed in the reportable events table that occurs within the specified time period after vaccination.

Question 22

What are some common precautions/contraindications?

Answer 22

allergies, pregnancy, immunosuppression, acute illness (moderate-severe)

Question 23

Special considerations for pregnancy patients

Answer 23

• can receive most inactivated vaccines
• cannot receive live vaccines, HPV, MenB, and non-aluminum adjuvanted vaccines (close contacts can)

Question 24

Considerations for immunosuppression

Answer 24

Inactivated vaccines: okay to administer, may have reduced response.
Live vaccine: DO NOT administer, could result severe reactions.

Question 25

Considerations for patients with HIV

Answer 25

vaccinate: inactive vaccines, MMR (if asymptomatic), varicella (asymptomatic children)
DO NOT vaccinate: LAIV, rotavirus, MMRV

Question 26

How does a stem cell transplant affect vaccine immunity?

Answer 26

• antibody titers decline 1-4 years after SCT
• patients should revaccinate with most inactivated vaccines 6 months after SCT

Question 27

Do antibootics affect vaccinations?

Answer 27

• routines are not affected
• oral typhoid vaccine replication is affected