Active & Passive Immunity/ Vaccinations

Question 1

Which kind of immunity does receiving preformed antibodies impart?

Answer 1

Passive immunity

• passive because antibodies are pre-formed, body doesn’t need to make them ‘actively’ against antigen
• transfer of active humoral immunity (antibodies from B cells) from one individual to another

Question 2

Which kind of immunity does exposure to exogenous antigens produce?

Answer 2

Active immunity

Question 3

Which immunity takes longer to develop?

Answer 3

Active immunity

Question 4

Which immunity develops rapidly?

Answer 4

Passive immunity

Question 5

How long does passive immunity last?

Answer 5

Short-lived protection—around 3 weeks to 4 months

because of short span of antibodies (half-life = 3 weeks)

Question 6

How does a person get passive immunity?

Answer 6

Maternal/ Natural passive immunity
is immunity passed along from mother to child
-trans-placental IgG
-breast milk IgA

Artificial passive immunity
comes from injected antibodies created within a different person or an animal. These antibody-containing preparations are termed antiserum
-rabies vaccine
-snake antivenom
-humanized monoclonal antibody (blood transfusion)

Question 7

Immunity gained by breast milk is which type of immunity?

Answer 7

Maternal/ Natural passive immunity

Question 8

What are examples of artificial passive immunity?

Answer 8

Antitoxins

• rabies vaccine
• snake antivenom

Humanized monoclonal antibodies

-abciximab

Question 9

How does a person get active immunity?

Answer 9

Natural immunity
-Natural infection

Artificial/ Vaccine-induced immunity

• vaccines
• toxoids

Question 10

How long does active immunity last?

Answer 10

Long-lasting protection (memory)

years even entire life-time

Question 11

A chickenpox infection will impart which type of immunity to a child?

Answer 11

Active immunity

Question 12

What are examples of natural passive immunity?

Answer 12

• trans-placental IgG
• breast milk IgA

maternal/ natural passive immunity
is immunity passed along from mother to child

Question 13

Which immunity develops after exposure to tetanus toxin?

Answer 13

Passive immunity

Question 14

Preformed antibodies are administered to unvaccinated patients after exposure to which type of toxins?

Which cells provide these antibodies?

What type of immunity will this provide?

Answer 14

Tetanus

HBV

Varicella

Rabies virus

Botulinum toxin

Diphtheria toxin

(To Heal Very Rapidly Before Disease)

B cells

Passive immunity

Question 15

Which immunity involves both humoral and cell mediated immunity?

Answer 15

Active immunity

vaccination

Question 16

What is secondary immune response?

Answer 16

The first exposure leads to primary response (formation of long-lasting memory cells) and incase of a subsequent exposure to same pathogen later, a much faster and stronger secondary response is established.

(eg “booster” shots) evokes a secondary response (anamnestic, memory, or booster response) that is stronger, peaks in 2–7 days, and last months to years

The main antibody is of the IgG type

Question 17

Which type of immunity is not suitable for immunocompromised patients?

Why?

Answer 17

Active immunity

Because even live attenuated vaccines (active immunity) can cause significant disease (there is potential for live organism to revert back to virulent form and the immunocompromised individual cannot form an adequate immune response)

Question 18

Which type of conditions benefit from both active & passive immunity?

Answer 18

Hepatitis B

Rabies exposure

Question 19

What is live attenuated vaccine?

Which type of immune response?

Answer 19

Microorganism rendered nonpathogenic but retains capacity for transient growth within inoculated host.

Induces cellular and humoral responses (Active artificial immunity)

Question 20

Give example of how passive immunity can be utilized as a treatment?

Answer 20

• Gamma-globulin (IgG) injection for HIV patients
• Hepatitis B antibodies to prevent infection even after exposure

(expensive because the half-life is ~30 days)

Question 21

What is advantage of live attenuated vaccine?

Answer 21

Induces strong, often lifelong immunity

Question 22

What is disadvantage of live attenuated vaccine?

Answer 22

may revert to virulent form

Contraindicated in pregnant and immunodeficient patients

Question 23

What are examples of live attenuated vaccines?

Answer 23

Attention Teachers Please Vaccinate SMALL Beautiful Young Infants with MMR Regularly

Adenovirus (nonattenuated, given to military recruits)

Typhoid (Ty21a, oral)

Polio (Sabin)

Varicella (chickenpox)

SMALLpox

BCG (TB)

Yellow fever

Influenza (intranasal)

MMR
Measles Mumps Rubella

Rotavirus

Question 24

In what condition can MMR and varicella vaccines be given to people living with HIV without evidence of
immunity?

Answer 24

If CD4 cell count ≥ 200 cells/mm3

Question 25

What type of immunity do vaccinations provide?

Answer 25

Active immunity (Humoral and/or cell-mediated immunity)

Question 26

Which type of vaccine in which pathogen is inactivated by heat or chemicals?

Answer 26

Killed or inactivated vaccine

Question 27

Killed or inactivated vaccine provide which type of immune response?

Answer 27

Humoral immunity

Question 28

What is disadvantage of killed vaccine?

Answer 28

- Weaker immune response | - Booster shots usually required

Question 29

What are examples of killed or inactivated vaccine?

Answer 29

A TRIP could Kill you Hepatitis A Typhoid (Vi polysaccharide, intramuscular) Rabies Influenza Polio (SalK)

Question 30

What is a subunit vaccine? Advantages? Disadvantages? Examples?

Answer 30

Vaccine with purified parts of the pathogen that are antigenic (elicit immune response) -doesn't contain the whole pathogen, unlike live attenuated or inactivated vaccine, but contains only the antigenic parts (proteins, polysaccharides or peptides) Advantages - safer, more stable (lower chance of adverse reactions) - well-established technology - suitable for immunocompromised individuals - can withstand changes in conditions (temperature, light exposure, humidity) Disadvantages - Complex & expensive to manufacture - Weaker immune response (require adjuvants and booster shots & time to examine which antigenic combinations work best) Examples ``` HBV (antigen = HBsAg), HPV (types 6, 11, 16, and 18), acellular pertussis (aP), Neisseria meningitidis (various strains), Streptococcus pneumoniae, Haemophilus influenzae type b. ```

Question 31

What is a subunit vaccine? Advantages? Disadvantages? Examples?

Answer 31

Vaccine with purified parts of the pathogen that are antigenic (elicit immune response) -doesn't contain the whole pathogen, unlike live attenuated or inactivated vaccine, but contains only the antigenic parts (proteins, polysaccharides or peptides) Advantages - safer, more stable (lower chance of adverse reactions) - well-established technology - suitable for immunocompromised individuals - can withstand changes in conditions (temperature, light exposure, humidity) Disadvantages - Complex & expensive to manufacture - Weaker immune response (require adjuvants and booster shots & time to examine which antigenic combinations work best) Examples Protein subunit - HBV (antigen = HBsAg) - acellular pertussis (aP) - HPV (types 6, 11, 16, and 18) Polysaccharide subunit - Neisseria meningitidis - Streptococcus pneumoniae Conjugate -Haemophilus influenzae type b

Question 32

What is a toxoid vaccine? Examples?

Answer 32

Denatured (inactivated) bacterial toxin proteins with an intact receptor binding site. Stimulates the immune system to make antibodies without potential for causing disease (prevents disease but not infection) toxoid: toxin like DTaP Diptheria, tetanus, acellular Pertussis Clostridium tetani (tetanospasmin) Corynebacterium diphtheriae (dipth toxin) * remember point tetanus: its symptoms are not caused by the Clostridium tetani bacterium, but by a neurotoxin it produces (tetanospasmin) *Whole-cell pertussis vaccines contain the entire inactivated organism while acellular pertussis vaccines contain parts (subunits) including the pertussis toxin alone or with components such as filamentous haemagglutinin, fimbrial antigens and pertactin

Question 33

Advantages of toxoid vaccine? Disadvantages

Answer 33

Pros - safe (cannot cause the disease & no possibility of reversion to virulence) - cannot spread to unimmunized individuals (vaccine antigens are not actively multiplying) - stable & long lasting (suitable for temperature, humidity and light) Cons - need an adjuvant and require several doses - local reactions at the vaccine site are more common—(may be due to the adjuvant or a type III (Arthus) reaction: reaction results from excess antibody at the site complexing with toxoid molecules and activating complement by the classical pathway causing an acute local inflammatory reaction)

Question 34

Which immunoglobulins do polysaccharide vaccines produce?

Answer 34

IgM | because inability of polysaccharide to activate Th cells which require protein to be activated

Question 35

What are some of the risks associated with artificial (passive) immunotherapy?

Answer 35

-IgE antibodies (produced against foreign species antibodies) → systemic anaphylaxis especially in patients with IgA deficiency (they have not encountered IgA before and they produce IgE after infusion with even human gamma globulins - therefore have to give IgA depleted globulins) - IgG & IgM anti-isotype antibodies can be formed against foreign antibodies → complement-activating immune complex → type III hypersensitivity reactions - IgG anti-allotype antibodies can be formed against minor polymorphic or other allotype immunoglobulins