Starlight - there's no mercury in the MMR. Even Halvorsen (owns a clinic selling single jabs, claims MMr is unsafe) says so, on his website.
There have been studies (hundreds of thousands of children) in several countries now, one of which is especially useful, for very apparent reasons: it's a whole population study in a first world country (Japan) where the MMR went from compulsory to unused, over a scare about the mumps element. They found that autism rose sharply while the MMR was not being used. They also found that some children died of measles, even with singles, when that hadn't happened with the MMR. (Leading to the conclusion that singles aren't as effective, and they went back to using the MMR.) Another huge study in Denmark, over half a million children, found that children were slightly less likely to be diagnosed with autism after vaccination.
Wakefield's research - which was only ever meant to be an observational, straw in the wind study of just 12 children in the first place - has in most scientists' minds been discredited by the preponderance of research since, showing no link. In fact 10 of the 13 researchers who worked with him have themselves said they disagree with the conclusion and that there's no link, and additionally Wakefield was (BEFORE the study in question) being paid half a million quid by lawyers acting for parents who were suing vaccine companies. He's also had some extremely serious accusations leveled at him in terms of falsifying the data, and having patented a rival vaccine, which would have been very profitable if the MMR had been withdrawn in its favour. This may all be irrelevant to his results, of course (he might well have been acting with the best intentions), but what is undeniable is that they've not been properly replicated by anyone else, despite much trying. Replication is one of the core requirements when testing a scientific hypothesis. If something is true then it holds true when more people try to prove it.
The US Center for Disease Control links to this side-by-side analysis of the science as it stood a couple of years ago. More studies strongly indicative of no link have been published since - and in peer-reviewed journals, which is rather important for self-evident reasons. The most recent study found no link, and it was actually designed in consultation with anti-vaccine groups, in an effort to resolve the problem.
The remaining suggestion is that there may or may not be a very small subset of children with ASD relations who have the condition "triggered" by vaccination, and the final bit of research has been commissioned into that specific area (as a small part of a huge and wide-ranging study into vaccine safety in general) by the US governmental organisation responsible, who obviously have a real responsibility to do so as vaccinations are more or less compulsory in much of the USA. They also stress that they need to fill any gaps in the research so they can effectively persuade people to vaccinate. The problem is it's very hard to prove or disprove, by the very nature of the dispute. I mean, you can postulate anything, it doesn't mean it's so, but it may be very hard indeed to find the evidence to conclusively say either way - which is why there's been such an explosion in research over the MMR. But the small subset theory is at this point a suggestion without any sort of evidential basis, and it's very hard to conclusively disprove, because ethically you can't create a double-blind controlled trial where vaccination is concerned. You can't give one set a placebo, one the MMR and one nothing and wait and see what happens - because not vaccinating is accepted by all the health bodies as dangerous, and you're damaging herd immunity by failing to do so, if the group is big enough to mean much (small groups are risky, because the results can be so skewed). And without such a trial all you can do is observational - find parents with ASD in the family and who have already decided to either refuse or accept vaccination for their kids, and see what happens. And it's also a tiny, tiny affected group, if it exists - not just a tiny proportion of all children, but a tiny proportion of children with ASD relations. If that group does exist - and it is, right now, an unsupported if - it's appalling and awful for their families, and it needs to be identified as soon as humanly possible, but it's also the case that measles can kill and vaccination needs to be widespread enough to prevent the disease gaining a hold. It kills a million children in the developing world every single year - that's why Bill Gates is funding vaccination programmes - and children have died recently in first world countries where measles has gained a foothold too, so it isn't the case that Western children are not affected.
It's also worth pointing out that the government don't in fact vaccinate, willy nilly. They decided against the chicken pox vaccination, which is in force elsewhere, on public health grounds. So the government doesn't, actually, take a blanket approach. Vaccination is expensive to administer on a whole population level, after all.
I wouldn't blame a parent with a close relative who was on the autistic spectrum for refusing to have their child vaccinated, because they obviously have to do what they think is right in the absence of definitive data (though it's also been reported that hardly any siblings of ASD children get the MMR, yet the incidence is hugely higher, nonetheless) but tbh I would blame those not in that sort of situation, who don't. Herd immunity means all our kids are safe, and so much research has now been conducted into MMR safety, and it's overwhelmingly coming down on the side of their being no link. If there is a tiny subset at risk (which tbh I don't believe) then those children, no less than infants and children with allergies or immune system problems that make vaccination dangerous - depend on the rest of the not-risked population to vaccinate, to protect them as well.
If there is a conspiracy, and vaccination is in fact dangerous and we're all being misled, then it's one colossal and enormous conspiracy at all levels of health provision and research, and honestly it just seems a bit odd that so much research has now gone in favour of no link. You can't easily nobble that many scientists - I'll buy the odd few here or there, but all of them? (When some of the work has been done free, pro bono, precisely to avoid any apparent conflict of interest?) Plus the governmental and international organisations, and the health services of the world - are they all conspiring to damage our children just to benefit big pharma? It just seems more likely that they want to stop dreadful and communicable diseases killing and harming people, really.