Vaccines

Question 1

What causes small pox

Answer 1

Variola virus

Question 2

What causes cowpox

Answer 2

Vaccinia Virus
This is a milder disease that can affect humans and induce cross immunity to smallpox

Innoculation with vaccinia

Question 3

Disease that have been reduced because of vaccinations

Answer 3

Diphtheria
Measles
Mumps
Pertussis
Polio
Rubella
Tetanus
Haemophilus influenza type b
Hepatitis b

Question 4

Passive immunization

Answer 4

The transfer of maternal IgG antibody to the fetus in utero or IgA to the child’s gut from breast milk

Question 5

Active immunization

Answer 5

Vaccination with an antigen that elicits an immune response

Prior exposure to pathogen or related pathogen

The memory response (T cells, antibodies) protects from reinfection and/or disease

Question 6

There are immunoglubulins available for post-exposure prophy

Answer 6

From human:
-Hep   A and B
-measles
-rabies
-chickenpox,  VZV
-cytomegalovirus
-tetanus
From horse
-tetanus
-botulism
-diphtheria
Recombinant:
Ebola

Question 7

What can a vaccine do

Answer 7

Make the body think that it is infected
Elicits a memory of immune responses that is ready to go when a person is exposed to a pathogen

• blocks initial infection (sterilizing immunity)
• blocks spread in the body or establishment of chronic infection (HBV)
• lessen symptoms of infection
• shorten time of infection
• block the action of toxins (tetanus)
• reduce or eliminate the risk of virus-caused cancers (HBV, HPV)
• reduce opportunity of spread to other individuals by lowering the incidence in the population

Question 8

Herd immunity

Answer 8

By vaccinating you are reducing the opportunity of spread to other individuals thus lowering the incidence in a population

Vaccines are usually not 100% effective - some people will not develop a protective immune response and not all people will receive a vaccine.
If enough people are successfully vaccinated, the chain of transmission can be broken and the incidence of infection will drop.
The viral reproductive ratio (r) is reduced to r<1
If there is no animal reservoir then a disease might be eradicated. Smallpox was eradicated as of 1979
Polio?

Question 9

T/f measles outbreaks are entirely preventable

Answer 9

True

Vaccines must be used to be effective

Question 10

Vaccine strategies

Answer 10

Inactivated

Attenuated

Subunit

Vector vaccines

DNA vaccines

Question 11

Inactivated

Answer 11

Salk Polio vaccine, HAV, influenza shot.

Formalin (formaldehyde) is the most common inactivating agent.

Question 12

Attenuated

Answer 12

Sabin Polio Vaccine, Measles, Mumps, Rubella (MMR) VZV, Yellow Fever, Influenza nasal spray (FluMist).

Question 13

Subunit

Answer 13

HBV, HPV vaccines - make individual proteins from virus.

Question 14

Vector

Answer 14

in development
Use a different, non-pathogenic virus to deliver genes for the one you are immunizing against.
Ebola - use an attenuated animal virus vesicular stomatitis virus (VSV) and insert the gene for the Ebola envelope protein.
People are then infected with the rVSV-EBOV vaccine, the virus replicates a little but does not cause disease.
A strong immune response is made as for an attenuated vaccine.

Question 15

DNA vaccines

Answer 15

in development
Deliver a gene for a viral component directly using
DNA injected into the muscle.
The DNA is taken up by muscle cells that then make proteins for the antigenic component of the virus.

Question 16

Polio vaccines

Answer 16

1955 Jonas Salk - Inactivated Polio Vaccine (IPV) Formalin used to inactivate virus
Requires 3 doses
1958 Albert Sabin - Live attenuated Oral Polio Vaccine (OPV) strong immunity against all 3 forms of virus
replicates well in gut but not in nervous system
became the vaccine of choice during the control of polio
can revert to disease causing form in rare cases (1/750,000)
After polio became contained and rare, in US there has been a switch back to IPV for safety reasons.
Herd immunity keeps the population safe.
There is now a push to eradicate polio from the world.
There are no animal reservoirs besides non-human primates.

Question 17

Adjuvants

Answer 17

Agents like aluminum salts or oil emulsions like squalene that are added to non-live vaccine formulations

Question 18

How do adjuvants enhance the immune response

Answer 18

• Hold the antigen in place, allowing a greater length of time for a response and aiding in presentation of antigens to macrophages.
• Stimulate localized inflammatory/innate immune response which recruits T and B cells to the site, thus enhancing the adaptive response.

Question 19

How do adjuvants make is possible for less antigen to be used?

Answer 19

in each dose of vaccine, making a limited supply of flu vaccine, for example, be used in more people.
Adjuvants in flu vaccine are used in Europe but not the US.

Question 20

Preservatives

Answer 20

Thimerosal (merthiollate)
Prevent growth of bacteria and fungi
They are added to vials with multiple doses of the vaccine

Question 21

Thimerosal

Answer 21

compound containing ethylmercury it is cleared from the body more quickly than:
Methylmercury is the mercury compound that is in fish that we try to avoid it can build up in the body and be toxic.
Thimerosal was taken out of childhood vaccines in the United States in 2001.

Question 22

Which vaccine never has thimerosal

Answer 22

Measles, mumps, and rubella (MMR) vaccines

Varicella (chickenpox), inactivated polio (IPV), and pneumococcal conjugate

Question 23

Why are measles, whooping cough and polio returning?

Answer 23

NOT vaccinating