Question

a. What is the key difference between the Salk and the Sabin polio vaccine?

b. Polio is no longer endemic to America, meaning there are no natural cases of polio in the U.S. However, there is still polio in other parts of the world. Do you think it is still important to vaccinate children against polio in America? Why or why not?

c. Regarding the science of bias and vaccination concerns, why do people tend to value anecdotal information more than statistical studies?

d. What does it mean when we say pathogens are in an arms race with humans?

Answer 1

Answer a) Salk polio vaccine - It uses inactivated poliovirus, usually is injected via shot, and is called as IPV.

Sabin polio vaccine - This is given orally, is often called the OPV and it contains a live attenuated version of the virus.

Answer b) There are no polio cases in America but still the children need to get vaccinated against it because an unvaccinated traveller might get the virus from the other countries and can cause new outbreaks. Polio virus is very contagious and untill it is eradicated from the entire world, the vaccination should not stop. Wild polio virus is still there in other countries which can affect the unvaccinated susceptible children and can result in epidemic.

Answer c) People find anecdotes highly compelling. Humans are social story telling animal , we learn by others experiences. There is a confirmation bias, we tend to believe what we want to believe or already believe and we forget disconfirming evidence. This is human nature. Same goes with vaccination, people tend to believe what others close to them saying instead of what stats say.

Answer d) The pathogens in arms race with humans mean that Pathogens are evolving along with humans. They both are interlocked. When human are evolving so are pathogens. Pathogens are continuously evolving in order to develop better ways to fight and control their evolution. Humans have to deal with it. Flu is evolving at a very high rate and it is hard to suppress them or controlling them via vaccines. So pathogens are in race with humans for the survival.