Polio, a 20th Century Pandemic

Question 1

polio virus type

Answer 1

enterovirus

Question 2

enterovirus replication

Answer 2

binding

uncoating

translation

genome replication

capsid assembly, genome maturation

egression

Question 3

polio transmission route

Answer 3

faecal-oral through the intestine

Question 4

severe polio

Answer 4

polio myelitis- 5-10% mortality, 90% left with some residual paralysis

Question 5

2 polio vaccines

Answer 5

Salk vaccine- inactivated, injected and more expensive

Sabin vaccine- live attenuated, oral vaccine

Question 6

why was the Salk vaccine less convenient?

Answer 6

needed a cold chain- expensive
needed to be injected- less fun for kids
‘cutter’ incident, where a bunch of kids got polio after the vaccination

Question 7

why is polio considered eradicable?

Answer 7

no animal reservoir

a cheap, effective vaccine is available

immunity is life-long

the virus can only survive a short time in the environment

Question 8

reasons polio hasn’t been eradicated

Answer 8

polio can revert after vaccination

recombination with other enteroviruses

immunocompromised people/babies/etc can be putting ‘seeds’ into the population (shitting it out), which is hard to identify and stop

Question 9

new, more stable viral strain that could be developed into a vaccine

Answer 9

nOPV2