Q11 - Many vaccines create immunity

[ohthatpatrick]

Question Type:
Weaken (claim, not argument)

Stimulus Breakdown:
Conclusion: we can make a hep E vaccine.
Evidence: we have isolated a portion of hep E that stimulates antibody production.

Answer Anticipation:
Hard to prephrase this without more biological knowledge / cleverness. But it will suffice if we prephrase, "Given that we've isolated a suitable portion of hep E that will stimulate antibody production, how can we argue that we will NOT end up with a hep E vaccine that produces permanent immunity?"

Correct Answer:
A

Answer Choice Analysis:
(A) Yes, it turns out. I would have rejected this on a first pass, but this pushes back against the idea that exposure to the virus, via the vaccine, would produce "permanent immunity". This seems to provide counterexamples in which people were exposed to hep E as a child but still got hep E later in life (so exposure did NOT equal permanent immunity)

(B) This is a GOOD thing for the doc's claim.

(C) This is also good for the doc's claim.

(D) This has nothing to do with the feasibility of creating a vaccine that works.

(E) This is irrelevant, since NOT getting the disease sounds like the doc wins.

Takeaway/Pattern: The most helpful moment in reading this stimulus would be picking up on how extreme the conclusion is ... a PERMANENT immunity? We just need an answer to give us evidence that the vaccine wouldn't keep you disease free FOREVER, and (A) makes the case that previous exposure can still lead to later outbreaks.

#officialexplanation

[netkorea06]

Can anyone explain why (a) is the answer? Thanks.

[bbirdwell]

Here's a key point from the argument:

Exposure to the outer shell of a virus is as effective as being exposed to the whole virus...

This is to say that exposure to the outer shell and exposure to the virus itself are equally effective.

Then the conclusion:
Now that we have the outer shell of Hep E, we can produce permanent immunity.

(A) says that most people who have Hep E have already been exposed to the virus itself. This suggests that the vaccine will not be effective, because it is "as effective" as being exposed to the virus, which in the case of most people, was not effective.

See it?

[Payam.tari]

Hi,
I have a problem with the whole answer and question. I know that in such a problem we should consider everything as true and complete, but then there are instances in which we have to use our common sense which would be a public knowledge as well. We all know that we take vaccine (weak version of the virus) to become immune to future expose of the a actual virus. There is no doubt that the way body responds to the vaccine and the actual virus is the same by stimulating antibody production, but the difference comes in the result as we all know. Antibody wins against the weak virus and gets defeated against the actual virus. Otherwise, why would we even develop vaccines if the results were the same.
Now, on answer A, it is mentioned that many ppl have been exposed to hepatitis E in childhood. And therefore they are now sick. I don’t see how this is countering the doctor’s claim about the vaccine. As I mentioned above you can get seek if you are exposed to the actual virus for the first time and I believe this is part of common knowledge. I appreciate if you could tell me if I am looking at this correctly or not.

[wallace.rachael]

I have the same question as the person above.

[ohthatpatrick]

It's definitely true that the test wants us to use common sense, but I think you're flattering our common knowledge to say that we all know how vaccines work.

I certainly don't have a great idea how they do, so I guess I have an easier time with this question as a result.

Do all vaccines work the same way? You seem to be listing common facts about vaccines as though it is possible to generalize about all of them.

When they work, do they always provide immunity? Do they ever just provide decreased vulnerability (but not outright immunity)? Does their effectiveness ever fade (don't some viruses mutate into vaccine-resistant forms)?

Does it have to be true that for any given virus, you can make a vaccine that works?

I think you agree with the facts of the argument about how effective vaccines work: by prompting the body to create antibodies towards a certain virus with a weak form of the virus, we will have a built-in defense system against that virus should we ever encounter its real form in the future.

The argument is saying that
someone who got a chicken pox vaccine
vs.
someone who actually contracted chicken pox

will be equally immune to chicken pox in the future.

This is the idea of "equal effectiveness" in the argument, or as you referred to it, "the same results".

The key to the chicken pox example is that when a vaccine works, it achieves results that are equivalent to having actually had the disease. (Clearly, the experience of being vaccinated is different from the experience of actually having chicken pox, but those aren't the "results" we're referring to)

So consider a different type of disease, Disease X.

If someone who contracted Disease X as a kid got exposed to Disease X as an adult and still contracted the disease, would you think that it was possible to create a vaccine for Disease X?

It doesn't seem like it will be, since people who get Disease X and develop antibodies to it are nevertheless susceptible to Disease X in the future.

So how would a vaccine for Disease X circumvent that problem?

This is what (A) is describing. It's saying that people who get Hep E as an adult have already been exposed to it before. If prior exposure didn't help them create antibodies to ward off future vulnerability to Hep E, then a vaccine won't work for them (because a vaccine gives someone prior exposure to the disease in the hopes of creating antibodies that would ward off future vulnerability).

I hope this helps. Let me know if it's still irksome.

[andrea.devas]

I understand why (A) is the correct answer. What initially threw me off was the word "probably"- is that not too weak for this type of question?

[gplaya123]

Let me add my 2 cents:

First of all, I think takers should immediately see why this argument is flawed:
It says: to create successful vaccine, doctors must isolate the disease cause.
Then the stimulus goes and says yeah, we were able to isolate it so everything is going to work out.
Well, if you thought this argument was valid, think again:
this argument has committed a classic sufficient/necessary fallacy.
The stimulus told us that isolating disease cause is the necessary factor not a sufficient factor.
So now, all we got to do is found an answer choice that refers to such fallacy and the answer choice A certainly does the job:

Even young people got Hep. E even if they had them when they were young, this implicitly demonstrates the fact that isolating the disease cause isn't enough to give a person complete immunity.

B talks about animals; humans and animals have different immunity systems so it's out of scope

C talks about Hep. C. So out of scope

D talks about the number of infected people. We are talking about whether it will give complete immunity or not so out of scope.

E talks about chicken pox. It's out of scope. However, if anything at all, it actually strengthens the argument: yeah, the chicken pox gives people complete immunity, so why not Hep.E as well?

[andrew.penry]

If this would've been a MSS, which I had thought by just reading "most strongly.." I would've gotten this question right with answer E! Pays to read the whole stem, ha!