The advantage with having a live 'weakened' polio vaccine depends on the location of where it is to be administered. This is the same with Salk's vaccine. Because Sabin's vaccine is orally used, it is very useful in places where sanitary isn't a very big deal. It is also easy to administer. Kids like the idea of eating sweats, which you can but Sabin's vaccine in, better than the prospect of getting a 'shot'. However, it has to be refrigerated and kept cold, which could be a problem in hot areas. Then the use of Salk's vaccine would probably be more helpful. The costs of keeping the vaccines cool could be greater than the cost of the needles required in hot climates.
Another factor in deciding whether Salk's or Sabin's vaccine should be used is the people around the person to be vaccinated. If the people around the to be vaccinated person has a weakened immune system, then it is best to use Salk's. This is because the weakened virus, even though it is weakened, might overwhelm the immune system, which is weakened as well, causing the person to have polio. It is probably best to use Salk's vaccine in all cases where the people surrounding the person to be vaccinated isn't vaccinated. The risk of getting polio is very slim (around 7 per million) but the risk is still there. It is even greater when in contact with the feces of the person being vaccinated.
Sabin's vaccine should be used in areas where there is no trained personnel or equipment to give the shots the Salk's vaccine requires. The risk of getting polio from the vaccine is worth the risk of having an untrained personnel giving you shots. It could be fatal to have an untrained person give you shots.
There should be a test to see how "truly" effective each vaccine is. This would be considerably difficult. As I mentioned above, the 'weakened' polio virus might be more effective in animals that are tested, but would be less effective in humans. The best test would be to test it in humans. It would require humans to take the vaccine and then try to become infected with the virus. That would be a more accurate test. The hard part is to find people who are willing to take this test. The even harder part is to recruit enough people to make the test valid. However, this test is probably unnecessary. Both vaccines seem to be effective. The cases of polio in the world today is very small and is growing smaller every year.
Which vaccine should be used? Which is better? I think there is no correct answer. The good news is that this debate might be ending very soon. As more people in the world are taking polio vaccines, no matter which one, the people infected with polio decreases. In the future, the word 'polio' could be a thing of the past, much like smallpox is today.