Types of vaccines

Question 1

Live Attenuated

Answer 1

Live but weakened pathogen

natural viruses reproduce thousands of times
during an infection, vaccine viruses usually
reproduce fewer than 20 times.

not enough to make you sick, but enough to induce memory B cells

Ex: Measles, Mumps, Rubella
Chickenpox,
influenza (intranasal –> through nasal cavity)

Question 2

Live Attenuated advantages and disadvtages

Answer 2

Advantage : 1-2 doses provide
immunity that is usually life-long.

Limitation : usually cannot be
given to immunocompromised
people

Question 3

Inactivated

Answer 3

Pathogen killed with heat or
chemical

it cannot possibly reproduce itself to cause disease

Ex:
Inactivated polio
Influenza (shot)
Hep A
Rabies

Question 4

Inactivated advantages and disadvtages

Answer 4

Advantage : some can be given to
immunocompromised people

Limitation : usually needs several
doses to achieve immunity

Question 5

Subunit (Acellular)
Vaccines

Answer 5

Contains only the antigen –
protein marker

The antigen is made by yeast or bacteria

Need boosters and requires a lot of work to
synthesize and develop.

Ex Acellular pertussis
Hepatitis B
HPV

Question 6

Toxoid Vaccines

Answer 6

bacteria cause disease by making
toxins.

Toxoid vaccines are made by taking
toxins and inactivating them with a
chemical

the toxin, once inactivated, is called a toxoid

Ex.Tetanus,
diphtheria,

Question 7

Nucleic Acid (genetic material)
Vaccines

Answer 7

messenger RNA (mRNA) vaccine
contains mRNA that is the code,
or blueprint, for the spike protein
of the SARS-CoV-2 virus.

The vaccinated person’s dendritic
cells use the blueprint to make
the spike protein from the surface
of the virus.

The macrophage is displaying the antigen
and the immune response can begin…

Question 8

Herd immunity

Answer 8

When most people in a community have received a
vaccine for a particular disease, the chance of an
outbreak of that disease is greatly reduced.

protects the small number of people who cannot be

immunized or for whom the vaccine did not work.

effectiveness increases if as many people as
possible are vaccinated.

Question 9

Herd immunity percentage

Answer 9

80-94% needed for effectiveness

Question 10

As a result of herd immunity…

Answer 10

eliminated small pox world wide
Eliminated polio in the Americas
measles, mumps, rubella and diphtheria very rare in Canada

Question 11

What about pregnant women?

Answer 11

If not properly immunized against certain vaccine-preventable diseases:
increases risk of birth defects in fetus
increases risk of spontaneous abortion
Vaccines are generally safe for pregnany women or
women who hope to be pregnant.

We generally are on the side of caution with live attenuated
vaccines