UNDER pressure from the American Academy of Pediatricians, ABC tonight will include an extraordinary disclaimer on the first episode of its new series “Eli Stone” – reminding viewers that everything in the lawyer drama, which depicts real-life issues, is just fiction.

Why the unusual disclaimer?

Because the show perpetuates an insidious myth – namely, that childhood vaccines are a cause of autism.

At issue in the episode is whether the thimerosal preservative formerly used in vaccines causes autism. A jury in the show concludes the opposite of what just about everyone in the real world should now know: that the supposed vaccine-autism link is based on discredited studies and wacky activist assertions.

On the face of it, ABC’s disclaimer that the show is fiction seems unnecessary. Who’d really think a prime-time drama is a documentary?

Problem is, popular media and celebrities hold great sway over public opinion. A new report released by my organization, the American Council on Science and Health, notes that celebrities are making all sorts of mistaken assertions about public-health matters.

Whether it’s Sheryl Crow making a flap about the “danger” of heated plastic or Tom Cruise railing against the notion of mental illness, our scientists concluded the stars were wrong – but the public is listening to its idols.

It’s clear that celebrities, both as outspoken public figures and on TV shows, have a funny way of getting us to believe them – despite their absolute lack of expertise. Indeed, their actual expertise, like the expertise of the “Eli Stone” producers, lies in getting us to believe their fiction.

So it took an almost unprecedented move to get ABC to remind viewers that “Eli Stone” is just fiction.

The pediatricians’ association had actually called on ABC and its child-friendly parent, the Walt Disney Co., to cancel the episode. Of course, no group has any legal power to censor what we see on TV. But the call for ABC to voluntarily cancel the show encouraged the network to take some much-needed responsibility.

How outrageous is the episode? Consider how rare it is that a large group of physicians actually has the courage to take a stand like this – to risk coming off as censors. When else has such a large, mainstream group been able to reach a consensus and speak out against unscientific nonsense this way?

We should applaud the pediatricians’ move and encourage other serious science-oriented groups to take similar approaches in combating junk science.

Oh, and about “Eli Stone,” a crusading lawyer who has “visions” about how he can improve the world: Let’s keep a cautious eye on that show, while it lasts.

Jeff Stier is an associate director of the American Council on Science and Health (HealthFactsAndFears.com, ACSH.org).