Prevention Of Viral Infections_Vaccines

Question 1

The two types of immunization are❓

Answer 1

1. Passive Immunization:
   - acquired through maternal antibodies, antitoxins and immune globulins
2. Active Immunization:
   - acquired through natural infection, vaccines and toxoids
   - relatively permanent

Question 2

How does active Immunization work❓

Answer 2

Natural infection/artificial acquisition 
⬇️
Proliferation of T and B cells 
⬇️
Formation of effector and memory cells

*memory cells are the basis for the relatively permanent effects of vaccinations

Question 3

The role of memory B cells are affected by the incubation period of the pathogen in what way❓

Answer 3

Pathogens with a short incubation period such as influenza, the symptoms are already under way by the time memory cells are activated

There’s enough time to allow memory B cells response in pathogens with a long incubation period like poliovirus

Question 4

List the types of vaccines you know

Answer 4

Whole organism (Attenuated/Inactivated Viral or bacterial)

Purified macromolecules (polysaccharides, toxoid, recombinant antigen, recombinant vector)

DNA

Synthetic peptide

Multivalent subunit

Question 5

Many common vaccines used consist of inactivated or attenuated viral/bacterial cells

True or false

Answer 5

True

Question 6

Attenuated vaccines are weakened viruses achieved by growth under abnormal culture conditions

Give examples

Answer 6

TB/BCG (Bacillus Calmette-Guerin)

typhoid

Mumps

Measles

Polio (Sabin)

Rotavirus

Varicella zoster

Yellow fever

Question 7

List some advantages of attenuated vaccines

Answer 7

1. Capacity for transient growth
2. Prolonged immune system exposure
3. Single Immunizations
4. Replication within host cells

Question 8

List some disadvantages of attenuated vaccines

Answer 8

Possible reversion eg
Sabin polio 1 in 4million doses

Presence of other viruses as contaminants

Unforeseen complications

Question 9

Inactivated vaccines are used inactivates by heat, chemical agents or radiation

True or false

What does this cause❓

Answer 9

True

Loss of replication ability

Question 10

Which form of vaccines are more stable❓

What type of immunity would it induce❓

What is it’s booster requirement❓

What is it’s reversion tendency❓

Answer 10

Inactivated vaccines

Humoral immunity

Requires multiple boosters

They cannot revert to form virulent forms

Question 11

What are CRITICAL parts of inactivates vaccines❓

What are the most widely used forms❓

What are the effects❓

Answer 11

Adjuvants

Aluminum salts (hydroxide or phosphate)

Liberation of antigen, chemoattraction and inflammation