A recent anti-vaccination event at the Statehouse followed by a fundraiser at Muirfield Village was a useful reminder that a misguided movement is threatening public health in Ohio and elsewhere.

The event attracted special attention because Robert F. Kennedy Jr., son of the late U.S. senator, was the headliner. Along with his widely respected work as an environmental activist, Kennedy unfortunately has, with an organization he founded called Children’s Health Defense, lent credence to the thoroughly discredited idea that vaccines aren’t safe.

In a letter to The Dispatch, Kennedy took issue with being labeled “anti-vaccination,” insisting that he accepts the effectiveness of vaccination but is concerned that vaccines aren’t tested enough for safety.

Information from the U.S. Centers for Disease Control and Prevention lays out the rigorous process under which new vaccines are developed, tested in three phases of clinical trials and regularly monitored once they’re licensed.

Moreover, decades of thorough vaccination in the U.S. have eradicated terrifying diseases, including polio and smallpox, and have made many others, including tetanus and serious influenza, much rarer.

Yet, thanks to conspiracy theories and internet-fueled misinformation, vaccination rates are dropping and diseases of the past are reappearing.

Those who understand the threat should speak out in defense of medical science. Ohio lawmakers can address it through two related measures currently before them.

One is House Bill 132, sponsored by New Middletown Republican Rep. Don Manning. It would require school districts to inform parents that they can opt out of required vaccinations for their children simply by declaring that they have a religious or philosophical objection.

The information about opting out would have to be presented in the same format as the explanation of “mandatory” vaccines — falsely suggesting that the two choices are equally valid. They aren’t, and suggesting they are would be highly irresponsible at a time when measles outbreaks are popping up in neighboring states.

HB 132 has been parked in the House Primary and Secondary Education Committee since its introduction in March. It should stay there or be voted down.

Meanwhile, an amendment in the Senate version of the state budget goes in the other direction by authorizing private schools to exclude students whose parents cite philosophical or religious reasons for not having them vaccinated. Some parents at the anti-vaccine rally objected to the amendment, one woman complaining, “Getting medical exemptions is getting harder and harder.”

If that’s true, it’s likely because physicians are noting the reappearance of measles around the U.S., along with the spread of the anti-vaccination movement, and they are becoming less willing to be a part of it. Perhaps in the past, when opt-outs were rarer, they could employ a more-expansive definition of a medical reason for avoiding vaccination and be confident it wouldn’t affect the general population. Now, with more children going unvaccinated and herd immunity threatened, the stakes are higher.

Most states still allow religious and philosophical exemptions, but California ended them in 2014 — after an outbreak of measles at Disneyland — and Washington, which has suffered several cases, is considering doing so. Allowing private schools in Ohio to protect their students against unnecessary risk would be a good start.

If Ohio decides to make it harder rather than easier to make the irrational choice of spurning vaccines, perhaps we can be spared our own unnecessary disease outbreak.