vaccines

Question 1

live attenuated vaccine

Answer 1

• weakened form of virus/bug produced via repeated passage thru subculture
• pros: produce immune response similar to natural infection, usually only need 1 dose
• cons: severe reactions possible, can replicate so can mutate, fragile (require cold chain), response can be inhibited by circulating antibody
• ex: sabin, measles, MMR, varicella, zoster, BCG

Question 2

inactivated vaccine

Answer 2

• whole killed organisms or fractional/subunit components
• pros: can’t replicate so no threat of disease
• cons: less effective, humoral response => require 3-5 doses/boosters, not inhibited by circulating antibody
• whole cell ex: salk, pertussis
• fractional ex: tetanus toxoid, flu, HPV, newer zoster

Question 3

conjugated vaccines

Answer 3

• combine weak (polysaccharide or oligosaccharide) antigen with strong antigen (protein carrier) => T cell dependent B cell response (IgG)
• ex: pneumococcal, HiB

Question 4

adjuvant

Answer 4

used to:

• increase magnitude of adaptive response to vaccine
• alter type of immune response (Th1 vs Th2, CD4 vs CD8, etc)
• increase T cell memory
• increase speed of response

Question 5

recombinant viral vector vaccines

Answer 5

• viral vector expresses heterologous antigen and induces antigen-specific cellular immune response w/o requiring adjuvant
• ex: new Mtb vaccine, ebola

Question 6

diseases eradicated (or eradicatable) with vaccine

Answer 6

• smallpox
• polio
• measles
• HiB (in US)

Question 7

measles vaccine

Answer 7

• live virus
• pros: very effective, lifelong immunity
• cons: people think MMR causes autism (nope)

Question 8

varicella vaccine

Answer 8

• live virus

- pros: very effective

Question 9

zoster vaccine

Answer 9

• higher dose of varicella live virus vaccine

- has been replaced by a recombinant viral vector vaccine

Question 10

polio vaccine

Answer 10

• salk = inactivated vaccine
• sabin = oral, live attenuated vaccine => allows person to person transmission but also risk of reversion to virulent strain

Question 11

BCG

Answer 11

• live attenuated m. bovis

- cons: only protective 10-20 yrs and variable protection

Question 12

pertussis vaccine

Answer 12

• DTP = whole cell vaccine => pretty effective after 3 doses, 5-10yrs, common adverse rxns
• TDaP = acellular subunit vaccine => less reactogenic (less adverse effects but maybe less durable tx)

Question 13

tetanus toxoid vaccine

Answer 13

• formalin inactivated toxin

- pro: very effective after 3-4 doses + booster every 10 yrs

Question 14

influenza vaccine

Answer 14

• trivalent influenza vaccine = inactivated subunit vaccine, injected, local rxns but few other side effects
• live attenuated vaccine = nasal route, associated with URI in adults and asthma flares in kids

Question 15

HPV vaccine

Answer 15

• virus like particle = self-assembling structural polypeptide (capsomere)
• 9-valent and 4-valent
• 100% efficacy

Question 16

recombinant zoster

Answer 16

• VZV glycoprotein + adjuvant
• pros: very effective
• cons: pain, fever/chills

Question 17

new Mtb vaccine

Answer 17

• recombinant; 2 Mtb antigens + adjuvant

- 50% efficacy at 3 years

Question 18

Ebola vaccine

Answer 18

• recombinant, replication competent VSV expressing ZEBOV glycoprotein
• pros: 100% efficacy

Question 19

Pneumococcal PPV23 vaccine

Answer 19

• pure polysaccharide covering 23 strains

- ineffective in kids < 2 yrs

Question 20

Pneumococcal PCV7/PCV13

Answer 20

• polysaccharide conjugated to non-toxic diphtheria toxin

- highly immunogenic in children/infants => more effective but more adverse rxns

Question 21

HiB vaccine

Answer 21

• conjugate polysaccharide vaccine

- largely eliminated HiB meningitis in kids in the US

Question 22

fractional vaccines

Answer 22

• subunit = isolated antigen (protein or polysaccharide)

- toxoid = inactivated toxins

Question 23

typhoid vaccine

Answer 23

• capsular polysaccharide vaccine