Outbreaks of Rift Valley fever occur irregularly in East Africa, several years apart. When outbreaks do occur, they kill thousands...
GMAT Critical Reasoning : (CR) Questions
Outbreaks of Rift Valley fever occur irregularly in East Africa, several years apart. When outbreaks do occur, they kill thousands of cattle. A livestock vaccine against the disease exists but is rarely used. It is too expensive for farmers to use routinely, and since it is not effective until a month after vaccination, administering it after an outbreak begins helps very little. Nevertheless, experts predict that use of the vaccine will increase significantly within the next few years.
Which of the following, if true, provides the strongest justification for the experts' prediction?
Passage Analysis:
| Text from Passage | Analysis |
| Outbreaks of Rift Valley fever occur irregularly in East Africa, several years apart. |
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| When outbreaks do occur, they kill thousands of cattle. |
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| A livestock vaccine against the disease exists but is rarely used. |
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| It is too expensive for farmers to use routinely, and since it is not effective until a month after vaccination, administering it after an outbreak begins helps very little. |
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| Nevertheless, experts predict that use of the vaccine will increase significantly within the next few years. |
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Argument Flow:
The passage sets up a contradiction by first explaining why a vaccine isn't used (irregular disease, high costs, timing problems), then stating that experts predict increased usage anyway. This creates a puzzle that needs explaining.
Main Conclusion:
Experts predict that vaccine use will increase significantly within the next few years, despite current barriers to its use.
Logical Structure:
The argument presents a seemingly contradictory situation - all the evidence suggests farmers have good reasons not to use the vaccine, yet experts predict usage will increase. We need to find what factor could overcome the established barriers of cost and timing.
Prethinking:
Question type:
Strengthen - We need to find information that makes the experts' prediction more believable. The experts predict vaccine use will increase significantly despite the current barriers (cost and timing issues).
Precision of Claims
The key claim is about future activity - 'use of the vaccine will increase significantly within the next few years.' We need to respect the facts about current barriers: expensive for routine use, takes a month to be effective, and outbreaks are irregular.
Strategy
We need to find scenarios that would overcome or reduce the impact of the stated barriers. The barriers are: (1) too expensive for routine use, (2) one-month delay before effectiveness, and (3) irregular outbreak timing. Strong scenarios would either reduce these barriers or create new incentives that outweigh them.
This tells us that mosquitoes spread the disease and that insecticide control is impractical due to the outbreak's widespread nature. While this explains why controlling mosquitoes won't work, it doesn't address any of the vaccine barriers we identified (cost, timing, irregularity). Knowing that insecticides don't work doesn't make the vaccine any cheaper or faster-acting, so this doesn't justify increased vaccine usage.
This explains that unaffected countries refuse to import livestock during outbreaks, which could create economic pressure on farmers to prevent outbreaks. However, this still doesn't solve the fundamental timing and cost problems with the vaccine. Even if farmers have more incentive to prevent outbreaks, they'd still face the same barriers: the vaccine is expensive for routine use and takes a month to work, while outbreaks are unpredictable.
This addresses vaccine production capacity, stating that producers could adjust operations quickly to meet increased demand. But this misses the point entirely - the issue isn't supply capacity, it's demand. Farmers aren't avoiding the vaccine because it's unavailable; they're avoiding it because it's expensive and ineffective when used after outbreaks begin. Increasing production capacity doesn't solve the cost or timing barriers.
This tells us that nomadic and remote farmers are particularly affected by outbreaks due to limited access to veterinary medicine. While this identifies a vulnerable population, it actually reinforces the barriers rather than overcoming them. If these farmers have little access to modern veterinary medicine, they're even less likely to use an expensive vaccine, making increased usage seem less likely, not more likely.
This provides crucial information that research has identified climatic conditions that predict outbreaks within 2-5 months. This completely transforms the vaccine's utility because it solves the timing problem. Instead of trying to use the vaccine after an outbreak begins (when it's too late), farmers could now vaccinate their cattle when they see the predictive climatic conditions, giving the vaccine its full month to become effective before the outbreak occurs. This early warning system makes the vaccine strategically valuable rather than merely reactive, providing strong justification for why experts would predict increased usage.