Vaccines

Question 1

Types of Vaccines

Answer 1

1. Live attenuated
2. Inactivated
3. Subunit (Protein, Polysaccharide, Conjugate)
4. Toxoid

Question 2

Live Attenuated Vaccines

Answer 2

Made from weakened form of pathogen. Trigger immune system but do not cause disease. Considered less safe than inactivated vaccines but have stronger immune response. Avoid in immunocompromised.
Eg. BCG, Oral Polio, Measles, Rotavisus, Yellow Fever, varicella

Question 3

Inactivated Vaccines

Answer 3

Prepared from the pathogens that have been killed by physical or chemical treatments. Cannot cause disease. Very safe but lower immune response compared live attenuated vaccines.
Eg. Whole-cell Pertussis, Inactivated Polio

Question 4

Subunit (Recombinant) vaccines

Answer 4

Uses antigenic parts of pathogen to elicit immune response. No pathogenic component so they are safe to use. Lower immune response than live attenuated.
3 types: Protein, polysaccharide, conjugate

Question 5

Protein based subunit vaccine

Answer 5

Uses protein based subunit as antigen of pathogen.
Eg. Hepatitis B vaccine

Question 6

Polysaccharide vaccines

Answer 6

Uses polysaccharide molecules present in bacterial cell wall. Less effective in children.
Eg. Meningococcal serogroup vaccines

Question 7

Conjugate vaccine

Answer 7

Conjugating polysaccharide to antigen which immune system is better able to respond to.
Eg. Heamophilus influenza type B

Question 8

Toxoid vaccine

Answer 8

Use toxin made by pathogen that causes disease. Causes immunity to the part of pathogen that causes disease, not pathogen itself.
Eg. tetanus, diphtheria

Question 9

Why do some vaccines require more than 1 dose?

Answer 9

1. First dose doesn’t provide as much immunity as is possible.
2. Immunity begins to wear off, need a booster.
3. More than one dose needed for all individuals to have best response.
4. Pathogen changing disease changes from season to season.