Vaccines Flashcards
The only disease we have completely eradicated off the face of the planet is ____?
Small pox
The four types of acquired immunity
Natural active
Natural passive
Artificial active
Artificial passive
Natural active immunity
Like after getting sick, body creates antibodies
Natural passive immunity
Prenatal and post-natal mother child relationship (IgG antibodies through placenta)
Active artificial immunity
Vaccination
Active passive immunity
Preparation of antibodies can be given medically to immunocompromised patients
______ and _______ bacteria have killed more people than any other infectious diseases
Smallpox
Plague
IN the first half of the 1900s, smallpox was killing ______ people worldwide each year
4 million
In 1958, what did the Soviet Union do to address smallpox?
Proposed the global eradication of smallpox by using a concentrated vaccination program
Why could smallpox be eradicated?
It only infects humans
The smallpox eradication program started in _____ and the last case was in _____
Late 1960s
1977
What percent of people needs to be vaccinated for eradication?
90%
We are getting very close to eradicating _______ and _______
Measles
Polio
What do vaccines do?
Safely elicit an adaptive (T cell and B cell) immune response to pathogenic microbes
In vaccine’s process, they stimulate..
High-affinity antibodies
Class switching of antibodies (IgG, IgA)
Memory T cells and B cells
What are the two types of vaccines?
Inactivated (all bacteria and some viruses)
Attenuated-live (some viruses)
Two types of attenuation
- Use of a similar virus that is non-pathogenic
- Serial passage of pathogenic cell virus in cell culture or embryonate eggs
Use of a similar virus that is non-pathogenic relies on…
Cross-reactive immunity
Serial passage of pathogenic cell virus in cell culture or embryonate eggs
Since cells and eggs have no immune system, mutant viruses arise that lose virulence (like a serial dilution)
Most attenuated vaccines are for…
Viruses
Bacterial attenuated vaccines are..
Anthrax and tuberculosis
Inactivation (types)
Formalin (37% formaldehyde)
B-Propiolactone (BPL)
Formalin
Cross-links proteins and nucleic acids, used for toxoid (inactivated toxin) vaccines
Example of a toxoid vaccine
Tetanus
B-propiolactone (BPL)
Nucleic acid mutagen, breaks down rapidly
After 24 hours, what happens with BPL?
Virtually none exists in a vaccine preparation
Inactivated vaccines require…
An adjuvant (e.g. aluminum hydroxide) to stimulate the innate immune response
Inactivated vaccines: Whole-agent
Entire microbe is in the vaccine (inactivated poliovirus)
Inactivated vaccines: Toxoid
No cells, just their toxins (tetanus)
Inactivated vaccines: Protein subunit
Only antigenic subunits (acellular pertussis, hepatitis B)
Inactivated vaccines: Polysaccharide conjugate vaccines
By conjugating (covalently linking) polysaccharide antigens to proteins, the antigen becomes T-dependent
How is Streptococcus pneumoniae conjugated with Haemophilus influenzae?
Haemophilus influenzae has a thick capsule, conjugates proteins with polysaccharide to trick body to recognize capsule as foreign
Advantages of attenuation
Stronger antibody response Requires fewer boosters Longer memory Stimulates MHC I processing (cytotoxic T cells) More closely resembles natural infection
Disadvantages of attenuation
More expensive
Perishable
Pathogenic revertants
Possible contamination with other viruses
Pathogenic revertants
Live virus can mutate to get its pathogenicity back
Advantages of inactivation
Less expensive
Stable (room temp storage)
No chance of infection
Contaminating viruses will also be inactivated
Disadvantages of inactivation
Weaker antibody response Requires more boosters Shorter memory Does not stimulate MHC I processing (No Tc cells) Does not resemble natural infection
Prior to the use of routine immunization, _______ of children dies or were disabled by infectious diseases in the US
Thousands
Globally, measles still kills _____ people, mostly children, per year
700,000
By immunizing, the ____ of the disease and consequently the microbe decrease substantially
Incidence
For each infectious disease, a _____ _______ ________ ____ is needed to reduce the incidence of the disease to nearly zero
Target vaccine coverage rate
For measles, the target vaccine coverage rate is…
95%
The risk of vaccination is ___ ____, but the risk of not vaccinating is ___ _______
Not zero
Far greater
Large-scale population studies have shown that the incidence of autism spectrum disorders in vaccinated and unvaccinated populations is….
Virtually the same
Two examples to discredit the link between autism and vaccines
Genetic link to some ASD (X-linked)
Removal of Thimerosol has not decreased incidence of ASD
1972 Japan: mandatory vaccination at ___ _____ reduces the incidence of pertussis to fewer than ___ cases per year
3 months
300
What happened when Japan changed the vaccination age to 2 years because two children dies shortly after vaccination?
More than 13,000 cases of pertussis (whooping cough) with 41 deaths
What happened after Japan returned to their previous vaccine schedule?
Within a few years the incidence returned to 1972 levels
Vaccines are often…
Victims of their own success
Titer
Measure of antigen-specific antibody
Antibodies are generated in response to…
Infection or vaccination
Detection of IgM indicates…
Recent infection
Detection of IgG indicates..
Recent or distant infection
Serology
The study of blood antibodies
