Vaccines Flashcards
(36 cards)
How do we survive viral infections? When do we succub?
Our defenses recognize and defend against the pathogen; a successful virus infection must have modulated or bypassed the defense.
The AIDS pandemic, the appearance of SARS, as well as influenza epidemics serve as witness to?
the frailty of our natural defenses.
What is one of the most effective methods to prevent viral infection? What is their disadvantage?
A vaccine; they cause selective mutation against them.
Smallpox has been called the most ____ disease in history
distructive
Smallpox virus ___ crippled or disfigured what ratio of people?
killed; 1 in 20
Smallpox was the first virus to be eliminated by ____ ____
human intervention
Who was Edward Jenner?
The man who infected his gardener’s son with cowpox
Louis Pasteur prepared a vaccine against ____ out of a dried infected rabbit spinal cord
rabies
The WHO once immunized 127 million indian children against ____ in more than _____ villages in a day. What virus is rapidly disappearing in the US due to vaccination?
polio; 650,000; measles
R0 value is the number of secondary infections produced by an infectious person. for measles it is ___ to ___
12 to 18
What is the R0 value for smallpox? for the 1918 flu?
5-7; 2-3
the poliovirus eradication effort makes use of ____ ___ ___ ___ with live attenuated poliovirus vaccine
large-scale immunization campaigns
Features of virus that enable easier eradication:
No secondary host (human only); infection confers long-term immunity; one stable serotype
Who introduced the term “vaccination?
louis Pasteur, from vacca in honor of Jenner
When did Jenner do his experiment
May 1796
What is the procedure of injecting pus from smallpox lesions in hopes of a mild disease that would provide lifelong protection?
variolation
What are the two types of vaccination?
Active (killed virus generates cells against) Passive (short-term effects) use antibodies
How do mothers immunize their babies passively?
They pass antibodies through colostrum (antibody rich first milk) or by transfer of maternal antibody through the placenta, which provides a protective umbrella
Vaccines work because the immune system can ___ the identity of a virus years later, called ___ ___
recall; immune memory
Immune memory is maintained by dedicated _____ ; these cells provide a heightened ability to respond ____ to a subsequent infection
T and B lymphocytes; quickly
An effective vaccine must produce significant concentrations of specific antibodies at _____ of ____ ____
points of viral entry
A vaccine must induce protective immunity in a significant fraction of the population. __ ___ individual needs to be immunized to stop spread. This is called _____ ____ when it is sufficient to disrupt virus transmission. This threshold is agent and population specific, but is generally in the range of ___ to ___% of the population. If the percentage falls below this threshold, ____ can develop.
Not every; herd immunity; 80-95%; epidemics
The protection from a vaccine must be ___-term in order to be worthwhile. If a lifetime immunity from a ____ ______ cant be provided, additional immunizations called ___ ___ are effective. What do these do? Protective immunity requires the proper ____ _____ is mounted in order to be effective.
long; single administration; booster shots; they stimulate waning immunity; immune response
MMR stands for? What is the most successful type of it? What type of vaccine is it? What are the risks of this type of virus?
Measles, mumps, rubella; a live attenuated virus; the virions shouldn’t spread, a mild or inapparent disease occurs. Viral replication stimulates an immune response; An infection could spread to immunocompromised populations.