This winter, a glowing beacon appeared beside a state highway in Washington County. The sighting was significant.

Where was it?
Along Southwest Beaverton-Hillsdale Highway at Oleson Road, in unincorporated Washington County

What did it say?
The electronic billboard rotated between ads for Sprint cellphones, a veterinary clinic, a climate-change conspiracy website, and two warnings against childhood vaccines.

The anti-vaxx ads read: "Why are fully vaccinated students getting the whooping cough?" and "1 in 5 kids in E.R. for drug side effects are vaccine induced."

Who paid for it?
Oregonians for Medical Freedom, a nonprofit that's become a lobbying force in Salem against state requirements that school-age children be vaccinated. The group beat back legislation last year that would have ended a "personal belief" exemption for parents who don't want their kids vaccinated.

Senate Democrats withdrew the bill last year with a pledge to revisit it in the 2020 session. It was the first of several compromises with Republicans to get a floor vote on a carbon cap bill—a vote that never came.

Oregonians for Medical Freedom is buying billboard space across the state, but declined to say how much it is spending on them or how many billboards it has.

"We're working to bring this missing information to the public to protect the right to informed vaccination consent," says Vanessa Sheets, education adviser for the group. "Vaccination recommendations that are not rooted in scientific integrity are unethical and put our health at risk."

The billboard company Lamar Advertising did not respond to a request for comment.

Why does it matter?
In the middle of a severe flu season, anti-vaccine propaganda can have life-or-death consequences. And anti-vaxx forces appear to have beaten back the vaccination bill for a second consecutive legislative session. Staffers for state Sen. Elizabeth Steiner Hayward (D-Northwest Portland), who led the vaccination effort in 2019, say her office is not aware of any plans to bring it back this year.

"It's frustrating because it's such a misrepresentation," says Dr. Jay Rosenbloom, a Portland pediatrician and board member for Boost Oregon, a group that educates the public about vaccines. "It's scaring people."

Rosenbloom says he's not surprised a climate-change conspiracy ad would run intermittently with anti-vaccine warnings.

"They go together," he says. "I worry about children getting harmed from measles and meningitis, but I also worry that everybody who spends 10 minutes on the internet feels like they are experts."