5.1 Vaccinations Flashcards
What are the 2 ways in which we aquire immunity?
Give one natural and one artifical example for each
1) Active (own antibodies)
- Natural: exposure to infectious agent
- Artificial: immunisation
2) Passive (ready-made antibodies)
- Natural: maternal antibodies
- Artifical: antibodies from other source
Define active immunity
Do we have active immunity as infants and explain your answer
When do we have maternal antibodies present? What is a major factor determining when we have a decrease in these antibodies?
Active immunity is protection that is produced by an individuals own immune system and is usually long lasting
Infants are born with Passive immunity but this doesn’t last for long. It changes later in life (very quickly) into an active immune system
Before birth we have maternal antibodies, after birth (depending on if the baby is breast fed or not) there is a decrease in maternal antibodies.
Define the following terms:
A) vaccination
B) immunization
A) The process of administering a vaccine; exposing a person to material that is antigenic but not pathogenic
B) The process of inducing immunity to disease
- Immunity is usually acquired naturally, but can be induced by vaccination
What is the only disease to be erradicated from the world and how was this done?
Why was it easy to erradicate?
Small pox is the only disease to be eradicated from the world because of vacinations!
Small pox doesn’t have many natural reservoirs in the world (it’s mainly found on humans) hence, once removed from humans, the disease no longer exists.
List 6 reasons why someone shouldn’t be vaccinated
1) Allergy (to something in vaccine) OR reaction to previous vaccine
2) Fever
3) HIV infection
4) Immunodeficiency
5) Neurological disorder
6) Thrombocytopenia; platelet deficiency
Define Herd immunity and state why this is benefical
What is the % required to gain effective Herd immunity
Give 4 factors Herd immunity depends on
“Herd immunity is the state achieved when immunisation programmes reach sufficiently high coverage of the target population to interrupt transmission within the community”
Beneficial because it offers protection those those people in the community who cannot be vaccinated
95% of the population must be vaccinated to gain effective HERD immunity
Depends on:
• Degree to which disease is infectious
• Efficacy of vaccines
• Vulnerability of population
• Environmental factors
Give 6 characteristics of a good vaccine
1) Few side effects
2) Low cost
3) Stable with long shelf life (no special storage needs)
4) Give long-lasting, appropriate protection
5) The public must see more benefit than risk
6) Easy to administer
In general what are the 3 main types of vaccines and what are their subclasses?
1) Whole-organism vaccines
- killed (inactivated)
- attenuated
2) Purified macromolecules
- toxoids
- subunit vaccines
3) DNA/recombinant vaccine
Describe the structure of the Poliovirus and what disease it can lead to
What are the three serotypes of this virus?
A a small, icosahedral shaped, nonenveloped, positive RNA virus that can cause Poliomyelitis
Serotypes; P1, P2, and P3 (P1 is the most virulent and common)
What is Poliomyelitis?
What season is it most common in?
Explain how it effects the body
A viral disease (enteric) which may affect the spinal cord causing muscle weakness and paralysis. Most common in summer
1) virus enters the body through the mouth, usually from hands contaminated by an infected person.
2) it is mainly an intestinal infection (most cases) but from the gut can occasionally travel to the lymph nodes
3) from here it can infiltrate the CNS, and motor neurons are particularly affected which can lead to muscle weakness and paralysis (less than 1% of cases)
If the Polovirus invades the CNS and motor neurons what are the 3 types of Poliomyelitis can be caused?
Spinal polio -> paralysis in the spinal cord
Bulbar polio -> paralysis in brainstem
Bulbospinal polio -> paralysis in both
What were the 2 types of Polio vaccine made?
What type of vaccine are these both classified as but how do they differ?
1) Inactived Polio Vaccine (IPV) SALK
2) Oral Polio Vaccine (OPV) -Sabin
Both are “whole agent vaccines” but IPV uses an inactivated form of the virus whereas OPV uses an attenuated form of the virus
How is the Salk Vaccine (Polio) made and how does it function as a vaccine?
Salk (IPV) is a whole agent vaccine that is made by:
- Inactivating the virus (kills it) using formaldehyde
- which causes the epitopes to stay but the virus itself to be killed.
- the epitopes can then be presented to the immune system (act as PAMPs)
Give an advantage and disadvantage of the Salk vaccine
Advantage: the virus is not live, thus if made properly, would NOT cause disease
Salk vaccine disadvantage: the formaldehyde used, caused the immune system to recognise the killed virus differently to the live virus possibly risking a shortened period of immunity ➞ multiple doses were required needed
Give a classic vaccination used today that is a “whole agent vaccine” made through INACTIVATION
The Influenza vaccine
How is the Sabin vaccine (Polio) made and how does it function as a vaccine?
The Sabin vaccine (OPV) is a “whole agent vaccine” that is made by Attenuation
- This is a process that lessens the virulence of a microbe but does NOT kill it allowing it to stimulate an immune response without causing the disease
