Look how Asgrath states a couple of totally irrelevant facts about polio vaccine (and from the WHO besides) and thinks it is 'research'.
It is a FACT that up until a few years before I was born polio vaccines had, among other contaminates that nobody knew about, a virus called SV40. This virus is found in half of the cancer tumors to this day. That doesn't mean that it 'caused' all of the cancers (a profitable condition for the medical/industrial complex and one which is now very very common) but it is also very likely to be a contributing factor. Of course anyone who studies this finds problems in their career.
Most people don't understand the technology of cultivating viruses and how difficult it is to understand what is in the mix. The target virus (say polio in this case) was grown on monkey kidneys (or was back in the day) but a hell of a lot of other things grew as well. Impossible to sort them all out, and very difficult to even identify them. Even in recent times with the rotavirus vaccine several pig viruses were found long after they started injecting them into humans.
I might also note that the guy who holds the patents on rotavirus is Paul Offit who sits on various boards who decide what American kids should be shot up with. He won't say how much he makes off his patents. He was also on the panel where Dr. Baker of Baylor Medical School 'joked' that to get rid of the problem of people not wanting to shoot up their kids the U.S. should 'get rid of white people.' Dr. Paul Offit is the go-to guy for the mainstream media whenever they talk about vaccinations.
Another funny fact about polio is that the 47,500 kids in India who were paralyzed after getting Gates' vaccine got a problem which was 'clinically indistinguishable' from polio. But it was not polio because it came from a vaccine. To add insult to injury, the rate of physical damage from 'wild strain polio' in India was already very low before Bill Gates' 'philanthropy'.
Another thing which people don't know is that 'polio' was often not a crippling disease. My dad had it as a kid and when he was an adult he was in amazingly good physical condition. His job was to climb 200 ft trees talking off all of the limbs, cut to top out, and rig it with cables for high-lead logging. This is not a job for pussies.
A real doctor, and one who took a 90% pay cut in order to do the right thing by humanity, gave a pretty good series of lectures on the polio question. Very eye-opening. Here's a little clip of the hours of lectures I've seen (and downloaded so it doesn't get 'lost'):
https://www.youtube.com/watch?v=lqhnp-NYGC4