Immunizations

Question 1

1. Describe the principle of passive immunization as well as the advantages and disadvantages of each in a given clinical situation.

Answer 1

passive immunity is the transfer of immunity from one individual to another (naturally or as a treatment) ie. maternal IgG, clostrum (IgA), immunoglobulin, gamma globulin, or IVIG

can be use to prevent a specific disease in pre-exposure or post exposure (rabies)

advantages: rapid onset, no need for functional immune system, very effective
disadvantages: expensive, anaphylaxis and other adverse rxns, short duration of protection, parenteral admin.

Question 2

2. Describe the attenuated virus used in vaccines, and list the advantages and disadvantages.

Answer 2

attenuated vaccines= live vaccines (weakened)
contain a non-virulent mutant and retain their capacity to reproduce and provide prolonged and strong immune response; they have the potential to revert back to virulent form (RARELY), can cause dx in immunocompromised and can be shed

Question 3

2. Which antigens are contraindicated in pregnancy?

Answer 3

live-attenuated viruses can be transferred to the fetus if given to a pregnant mother

Question 4

3. Discucss the basic principles of vaccine policy. (goals)

Answer 4

to prevent disease in an individual, population

to eradicate disease

Question 5

4. Define the basic terminology of vaccine epidemiology such as herd immunity, efficacy and immunogenicity.

Answer 5

immunogenicity: ability of the vaccine to produce a measurable immune response in a population (does not mean neutralizing immunization)

vaccine efficacy: ability of vaccine to prevent disease in a population

herd immunity: high enough percentage of population is immunized that an unimmunized person is unlike to be exposed to the disease

Question 6

5. Explain the factors that result in under-immunization.

Answer 6

parental apathy, lack of knowledge and forgetfulness
doctor ignorance
parental concern
missed opportunity
cost
number of injections per visit/complicated schedule
culture/religion
logistical: transport, wait times, appt. scheduling
vaccine shortages
record keeping
liability of adverse events
lack of access to care

Question 7

1. Describe the principles of active and passive immunization as well as the advantages and disadvantages of each in a given clinical situation.

Answer 7

application of antigen to the host in order to induce an immune response which prevents further episodes of the disease by inducing an immunological memory

memory cells allow for a more rapid immune response that neutralize infection before it can cause significant disease (antibodies must neutralize to be effective)

booster doses generate further memory cells and antibody producing cells, resulting in sustained response

Question 8

Name diseases in which passive immunization is used as a treatment.

Answer 8

tetanus, rabies, botulism, Diphtheria, measles, Hep A, B, Varicella, CMV, RSV, snake bite venom and TSS.

also used as an immune-modulator in Kawasaki Disease, Guillain-Barre and Idiopathic thrombocytopenia purpura

Question 9

List different sources of immunoglobulin.

Answer 9

horse immunoglobulin
pooled human plasma
specific high titer human immunoglobulin (harvested after immunization)
monoclonal antibody: produced in lab in cell culture

Question 10

2. Describe the inactivated virus used in vaccines, and list the advantages and disadvantages.

Answer 10

inactivated vaccines= killed vaccines; virus is killed by heat or chemical means, elicit mainly a humoral response and usually require boosters and contain a complex mix of antigens (potential for adverse events)

Question 11

2. Describe the purified subunit formulation used in vaccines, and list the advantages and disadvantages.

Answer 11

contain one or more purified molecules from the organism, have the same characteristics as inactivated vaccines except lower adverse event rate (i.e. toxoid vaccines- inactivated bacterial exotoxin, polysaccharide vaccines, conjugate polysaccharide vaccine and surface antigen vaccines)

Question 12

What is contained in a vaccine besides the antigen?

Answer 12

adjuvant (increase antibody response by binding to antigen and increases uptake of antigen and increases synthesis of cytokines)
preservatives
antibiotics (as preservatives)
trace materials from production ie. yeast or egg protein

Question 13

What can be done to improve immunization rates?

Answer 13

immunize early and at every opportunity
get out of the clinic
state school/day care passport laws
public education and advocacy
combined vaccines to decrease # of visits required