Top Law Schools

For D to be correct, we have to assume that the vaccine is effective for a lifetime once you get yourself vaccinated for that strain.


Is the common-sense assumption to make? I assumed the focus group should take the vaccine every year for a particular strain irrespective of whether they have taken the vaccine for that strain previously.

I was looking for an answer along the lines - "Only the less prevalent virus strains cause the most serious complications"

This is a Sufficient assumption question, so we're trying to guarantee the validity of the conclusion. In this case, that is: every year it will be necessary for all high-risk individuals to receive a vaccine for a different strain of the virus.

In terms of modality/logical force, this is a very strong conclusion. It uses the word "necessary," so we need some evidence that will prove that the high-risk individuals absolutely need to receive a vaccine for a different strain every year.

(D) says: Each year the strain of influenza virus deemed most likely to be prevalent will be one that had not previously been deemed most likely to be prevalent.

You said that we have to assume that the vaccine is effective for a lifetime for D to be correct. I think I can see where you're coming from with that, but it isn't actually true. Even if the vaccines last only, say, a year, if we also take D into account, that the most prevalent virus changes every year, the conclusion still holds.

Look again at this premise: Each year’s vaccination will protect only against the strain of the influenza virus deemed most likely to be prevalent that year. No matter how long the vaccinations last, if the most prevalent strain changes every year, the high-risk individuals will have to get a vaccine for that new strain each year.

If the vaccines last for only a year, or any amount of time under a lifetime, perhaps they'll have to get vaccines for those old strains again in addition to ones for the new strains. But we don't know for sure, and more importantly, it's not relevant to the conclusion, so it doesn't matter.

.

Perfect ...I got it .. thanks for your responses!