Pertussis Outbreaks Flashcards
What is the background information on the pertussis outbreaks of the 2000’s?
Outbreaks of pertussis, otherwise known as whooping cough, in the 2000’s in vaccinated ppl
-highest incidence rate in 1 y/o or less
Why was the highest incidence rate in 1 y/o or less?
Haven’t received full series of vaccines
Immature adaptive immunity
Normal bacterial flora not fully developed
less herd immunity
What was the first kind of pertussis vaccine used? What are the characteristics?
Whole Cell Vaccine, wP used starting in 1950’s
- Bacteria grown in lab then killed w/ heat
- can’t cause infection b/c dead
- bordatella pertussis is the antigen recognized
- Main side effect are allergies due to antigens like aniphylaxis
How does a vaccine create immunologic memory?
When injected, antigens on dead bacteria are recognized by PAMPs which stimulate innate response and lead to adaptive response
-PAMPs to Innate to Adaptive to Antigens to Memory
What was the 2nd kind of pertussis vaccine used? What are the characteristics?
Acellular Vaccine, aP
-Removed most of the antigens to prevent allergic reactions
What are the key antigens that were kept in the aP vaccine?
- Pertussis Toxin - most dangerous, causes infection
- Filamentous Hemagglutinin (FHA) - attachment protein used to colonize resp. system. Important virulence factor that can overcome resp. defense mucus
- Pertactin - surface antigen important for antibodies to recognize/coat pathogen for opsonization
The aP vaccine stopped lasting as long as the wP. How was this addressed?
TdAP
Why was there an increase in Pertussis outbreaks?
Due to change in vaccine
- the pressure to mutate was much higher w/ acellular vaccine due to only a few antigens present
- less antigens in aP gives bigger bang for buck with one mutation
- more antigens in wP vaccine = less pressure to mutate
