"It doesn't matter that [Wakefield] was fraudulent," said Offit, a vaccine inventor who often counters attacks against the products. "It only matters that he was wrong."
The debate is not just academic. Fear of autism prompted some parents here and abroad to balk at vaccinating their children, leading to measles outbreaks and, in the United Kingdom, several deaths.
Some autism researchers say the issue also has diverted energy and money away from the bigger effort of finding causes and cures for the disorder, likely set in motion before birth.
Wakefield could not be reached for comment Thursday. A spokeswoman for Skyhorse Publishing, which produced his book, Callous Disregard: Autism and Vaccines - The Truth Behind a Tragedy, said he was in Jamaica at a conference.
The 1998 study Wakefield led acknowledged that it had not definitively proved an autism-vaccine link.
Skyhorse Publishing has released a statement saying that Wakefield believed the assertions in the BMJ article were "entirely false."
BMJ's article against Wakefield was the first in a three-part series. It caps a year of rebuke for Wakefield.
In January 2010, a panel of the United Kingdom's General Medical Council found that he had acted irresponsibly and with "callous disregard" to the children involved in his research.
In the 1998 study, Wakefield and 12 other scientists connected a decline in childhood development and a rise in gastrointestinal problems to vaccinations. The report looked at just 12 children. Ten of the authors renounced the study in 2004 after it was revealed that Wakefield had been paid by lawyers planning to sue vaccine manufacturers.
The problems with Wakefield's work detailed by BMJ are many and blatant: Three of the nine children listed in the study as autistic did not have the diagnosis. Although the study said developmental problems began around the time of vaccination, some actually began before the vaccines were given or well after. And children included in the study were recruited by antivaccine "campaigners," according to the article written by journalist Brian Deer.
Wakefield "is not a scientist," Offit said. "He is fanatical."
Some autism advocates reacted in frustration Thursday.
The attacks against Wakefield are "smoke and mirrors trying to deflect attention away" from the need for more research into vaccine safety, said Wendy Fournier, president of the National Autism Association, who believes her 10-year-old daughter's autism is connected to vaccines.
"As consumers, we have the right to ask questions without being labeled antivaccine," she said.
Autism includes a variety of disorders generally characterized by impaired social interaction and communication. Much is unknown about its causes, in part because its effects can be diverse.
Scientists have identified factors that increase risk, including advanced age of the parents, obstetric complications, and premature birth, said David Mandell, associate director of the Center for Autism Research at Children's Hospital of Philadelphia. Sporadic findings connect autism to prenatal exposure to toxics, he said.
It's likely that the causes of autism are a combination of environmental and genetic factors, Mandell said.
"It's not going to be vaccines," Mandell said. "It's going to be something that happens before kids are born. . . . That's where all the evidence is pointing."
And autism will likely not be one disease. Doctors are working to categorize it as many distinct diagnoses, he said.
A leading autism advocacy group, Autism Speaks, has tempered its comments about vaccines in recent years, saying on its website that the benefits of vaccination "outweigh the hypothesized risk" that they cause autism. The group steered clear Thursday from the fray over the journal article, declining individual interviews.
"It's really time to put this to rest," Mandell said.
Contact staff writer Chelsea Conaboy at 856-779-3893 or firstname.lastname@example.org.