Autism is a description of a set of symptoms, cause unknown.
http://www.cdc.gov/mmwr/preview/mmwrhtml/00046738.htm
One need only to look at the adverse side effects of say the dPt vaccine to see a set of symptoms - particularly the whole virus dPt vaccine that has been removed from the market. Um just happen to be the same set of symptoms that would describe say autism? Yep.
dPt symptoms neurologic illnesses, including encephalitis/encephalopathy and prolonged convulsions
autism symptoms abnormal functioning in three core areas of development: social interaction, verbal and nonverbal communication, and the presence of repetitive and restricted patterns of behavior, interests, and activities.
Impaired reciprocal social interaction such as poor use of body language and nonverbal communication, such as eye contact, facial expressions, and gestures;
lack of awareness of feelings of others and the expression of emotions, such as pleasure (laughing) or distress (crying), for reasons not apparent to others;
remaining aloof, preferring to be alone; difficulty interacting with other people and failure to make peer friendships; may not want to cuddle or be cuddled;
lack of or abnormal social play; not responding to verbal cues (acting as if deaf).
Impaired communication such as delay in, or the total lack of, the development of spoken language or speech; if speech is developed, it is abnormal in content and quality; difficulty expressing needs and wants, verbally and/or nonverbally; repeating words or phrases back when spoken to; inability to initiate or sustain conversation; absent or poorly developed imaginary play.
Restricted repertoire of interests, behaviors, and activities such as insisting on following routines and sameness, resisting change; ritualistic or compulsive behaviors; sustained odd play; repetitive body movements (hand flapping, rocking) and/or abnormal posture (toe walking); preoccupation with parts of objects or a fascination with repetitive movement (spinning wheels, turning on and off lights); narrow, restricted interests (dates/calendars, numbers, weather, movie credits).
Concern about the possible role of pertussis vaccine in causing neurologic reactions has been present since the earliest days of vaccine use. Rare but serious acute neurologic illnesses, including encephalitis/encephalopathy and prolonged convulsions, have been anecdotally reported following receipt of whole-cell pertussis vaccine given as DTP (62,63). Whether pertussis vaccine causes or is only coincidentally related to such illnesses or reveals an inevitable event has been difficult to determine conclusively for the following reasons: a) serious acute neurologic illnesses often occur or become manifest among children during the first year of life irrespective of vaccination; b) there is no specific clinical sign, pathologic finding, or laboratory test which can determine whether the illness is caused by the DTP; c) it may be difficult to determine with certainty whether infants less than 6 months of age are neurologically normal, which complicates assessment of whether vaccinees were already neurologically impaired before receiving DTP; and d) because these events are exceedingly rare, appropriately designed large studies are needed to address the question.
Despite these methodologic difficulties, the National Childhood Encephalopathy Study (NCES) and other controlled epidemiologic studies have provided evidence that DTP can cause acute encephalopathy (64-68). This adverse event occurs rarely, with an
estimated risk of zero to 10.5 episodes per million DTP vaccinations (68).
Among a subset of children who were participating in the NCES and who had infantile spasms, both DTP and DT vaccination appeared either to precipitate early manifestations of the condition or to lead to its identification by parents (70). IOM reviewed this and other studies and concluded that neither vaccine causes the illness (71,72).
IOM concluded recently that no available evidence indicates that DTP might cause transverse myelitis, other more subtle neurologic disorders (e.g., hyperactivity, learning disorders, and infantile autism), and progressive degenerative conditions of the CNS (4). Furthermore, one study indicated that children who received pertussis vaccine exhibited fewer school problems than those who did not, even after adjustment for socioeconomic status (77).
The most serious side effects of earlier "whole-cell" pertussis immunizations were neurological: and included seizures and hypotonic episodes. In addition, a number of children suffered allergic and adverse reactions to the pertussis vaccination, including severe seizures.
Much of the controversy surrounding the DPT vaccine in the 1970s and 1980s related to the question of whether the whole-cell pertussis component caused permanent brain injury in rare cases, called pertussis vaccine encephalopathy. Despite this possibility, doctors recommended the vaccine due to the overwhelming public health benefit, because the claimed rate was very low (one case per 310,000 immunizations, or about 50 cases out of the 15 million immunizations each year in the United States), and the risk of death from the disease was high (pertussis killed thousands of Americans each year before the vaccine was introduced).[8]
No studies showed a causal connection, and later studies showed no connection of any type between administration of the DPT vaccine and permanent brain injury. The alleged vaccine-induced brain damage proved to be an unrelated condition, infantile epilepsy.[9] Eventually evidence against the hypothesized existence of pertussis vaccine encephalopathy mounted to the point that in 1990, the Journal of American Medical Association called it a "myth" and "nonsense".[10]
However, before that point, criticism of the studies showing no connection and a few well-publicized anecdotal reports of permanent disability that were blamed on the DPT vaccine gave rise to anti-DPT movements in the 1970s.[11] The negative publicity and fear-mongering caused the immunization rate to fall in several countries, including Great Britain, Sweden, and Japan. In many cases, a dramatic increase in the incidence of pertussis followed.[12]
Unscientific claims about the vaccine pushed suppliers of the vaccines out of the market.[8] In the United States, low profit margins and an increase in vaccine-related lawsuits led many manufacturers to stop producing the DPT vaccine by the early 1980s.[8]
In 1982, the television documentary "DTP: Vaccine Roulette" depicted the lives of children whose severe disabilities were blamed on the DPT vaccine. The negative publicity generated by the documentary led to a tremendous increase in the number of lawsuits filed against vaccine manufacturers.[13] By 1985, manufacturers of vaccines had difficulty obtaining liability insurance. The price of the DPT vaccine skyrocketed, leading to shortages around the country. Only one manufacturer of the DPT vaccine remained in the U.S. by the end of 1985. To avert a vaccine crisis, Congress in 1986 passed the National Childhood Vaccine Injury Act (NCVIA), which established a federal no-fault system to compensate victims of injury caused by mandated vaccines.[14] The majority of claims that have been filed through the NCVIA have been related to injuries allegedly caused by the whole-cell DPT vaccine.
The concerns about side effects led Yuji Sato to introduce a safer acellular version of the pertussis vaccine for Japan in 1981. The acellular pertussis vaccine was approved in the United States in 1992 for use in the combination DTaP vaccine. Research has shown the acellular vaccine to be safer, with fewer reports of adverse effects.[15]
Although the whole-cell DPT vaccine is no longer used in the United States, it is still purchased by the World Health Organization and distributed to developing nations because of its much reduced cost compared to the acellular DTaP vaccine.
There is newly emerging evidence that some strains of the bacteria that cause pertussis have become resistant to the acellular version of the vaccine which is leading to a rise in the incidence of whooping cough in the wealthy countries that use it.[16
http://en.wikipedia.org/wiki/Pertussis