Despite developments that have kept mounting for the last few years discounting any connection between autism and the vaccine for measles, mumps and rubella (MMR), some people who have autism, as well as their families and friends, do not rule out such a connection.

The parents of Calvin Benbow are among that group. Calvin is just four and-a-half years old, but in that relatively short time, his life has undergone radical change. He is boisterous, curious, playful and talkative. That's a sharp contrast, however, to how he was three years ago, when he was first diagnosed with autism.

"He had no ability to ask for anything," his father, Chris Benbow tells PIX 11 News. "He couldn't point, he had no words, so he would sit and scream."

"There was no laughing, there was constant crying," his mother, Melody Benbow adds. "For us, it was devastating."

But now, the boy who has no trouble sitting quietly playing with an iPad or climbing over and through a makeshift obstacle course in the family playroom or any variety of activities in between, is just fine. So are his parents. However, what caused Calvin to be barely functioning before -- that is, what causes autism -- remains unknown. That's why his parents still insist on one thing.

"There must be more research done, especially on the vaccine front," Melody Benbow says, while her husband talks about any connection between childhood vaccines and autism this way: "If there's a link, let's fnid out that it is, and if there's not, let's definitely find out that it's not. Until then, why would we prematurely rule it out?"

A 1998 study by Dr. Andrew Wakefield and a dozen of his colleagues in the British medical journal The Lancet linked the MMR vaccine and autism. The publication of that research led to a worldwide decline in MMR vaccinations that has never fully recovered, despite damning evidence against Wakefield's research and against his expertise and practices as a medical professional.

In 2010, the British journalist Brian Deer wrote an article in another British medical journal, BMJ,, which compiled years of Deer's own work showing strong evidence that Wakfield falsified some of his research and used unethical and questionable methods to gather his results. Among Deer's findings specifically, five of Wakefield's twelve test subjects who had been listed as being normal before their MMR vaccinations did in fact have previously documented developmental problems. Also, Wakefield gathered blood samples from children attending a birthday party at his home for his seven year-old son. The British doctor paid each child five pounds sterling (about $7.50) for their blood donations, in flagrant violation of ethical medical practices.

Ten of the thirteen doctors who participated in the original Wakefield study renounced it, and The Lancet retracted its publication of the study. The British General Medical Council revoked Wakefield's medical license, and his research was widely dismissed as fraudulent.

"There truly is not a linkage between autism and vaccinations, based on the research available," neurodevelopment pediatrician Audrey Mars, M.D. tells PIX 11 News. Her opinion is representative of how most medical professionals regard this issue.

However, it's the end of Dr. Mars's statement, "based on the research available," that has families like Calvin Benbow's still unconvinced that there is no vaccine - autism link. They point out that even though the primary researcher linking vaccinations and autism has been disgraced, there is still no irrefutable evidence that vaccines and autism are not connected.

"For people to just dismiss [a link], for whatever reason, like it's definitely not that... I think it just glosses over it too quickly," Chris Benbow says. His wife adds, "There absolutely has to be more research done. We do have doctors and nurses saying there's something happening here, and we do need to look into these vaccines and what is going on."

Calvin's parents know that he seemed normal until he got his required vaccinations at 6 months and 12 months old. "He completely stopped developing," Melody Benbow says.

"He would just scream [non-stop]," his father tells PIX 11 News. "And we would grab the cup and show it to him, and he would just scream because he didn't want the cup, and we'd grab food, we'd grab toys, and once we found it he would stop screaming and there would be calm, but that was his only form of communication."

But to see four and-a-half-year-old Calvin now is to see a sharp contrast to that description. He appears to be pretty much like any other kid, including his three year-old sister, who does not have autism. What's changed for Calvin is where virtually every debate on the cause of autism leads.

"It's not just the vaccines," Melody Benbow says, "It's what's in them. It's what's in our environment. It's the preservatives, the chemicals. The big picture is what we need to look at." Since nobody can pinpoint the cause of autism, she says, what needs to be done is to treat the condition.

"We've done a lot of work to repair the damage that's been done," she says. "We took him off gluten, dairy and soy and found that after taking him off those, he improved tremendously."

She adds, "He was deficient in many things, vitamins and minerals. When we started adding those things to his diet, things changed as well."

Calvin and his sister take at least ten different vitamin supplements a day. Their parents taught them how to swallow the capsules, and Calvin prefers to take his without water. His parents found that by removing preservatives, chemicals and other toxins from Calvin's life, his life improved. His prospects did as well.

In addition to being able to control all of his emotions and motor skills, he talks quite a lot. One topic he discusses, much like any four year old, is what he wants to be when he grows up.

"A policeman!" is Calvin's answer, at least for now. Like so many children, his answer is highly subject to change. The fact that he can express his aspirations and that they stand a good chance of being realized is a testament to the efforts of trying to understand and treat autism, no matter what it's cause.

"There's a lot of hope," Calvin's dad says, contrasting his son's current status with the boy's past. "That day that the doctor tells you, 'Your child has autism,' you don't know what to think. You're almost speechless. It takes your breath away and your first thought is, 'He'll never be able to do this, he'll never be able to do that.' [But] there are so many programs that incorporate children with developmental disabilities, that all those things you didn't think were possible, they are possible."