President Donald Trump has sent mixed signals about COVID-19’s risks and how long Americans will need to stay at home to contain this new disease. But on Sunday he took a sensible new stance, extending strict social-distancing guidelines at least through April 30.

That’s 18 days beyond Easter, when Trump had hoped to see pews packed at churches to celebrate the Christian holy day. The extended guidelines appear to heed the concerns of Trump’s respected medical advisers and reflect a grim reality.

This is a new virus for which there are no proven treatments and no vaccine. The nation also appears to be on the front end of the contagion. Dr. Anthony Fauci, the longtime director of the National Institute of Allergy and Infectious Diseases, publicly estimated Sunday that 100,000 to 200,000 people in the U.S. could die of COVID-19, even with aggressive mitigation measures.

Still, dangerous COVID-19 denialism abounds. Some of it is fueled by amateur number-crunching about current confirmed cases and death rates. These lowball calculations have several major problems. Among them are the lack of testing and the fact that this is the early stage of the contagion in this country. Today’s numbers aren’t tomorrow’s numbers, and medical experts have a lot to learn about the behavior of this new coronavirus. How it acts in one location is no guarantee it will act the same in another.

Trump’s inconsistent statements about COVID-19 have also not been helpful in getting people to take this public health threat seriously. He downplayed the disease’s spread earlier this year, and since then his statements have varied week to week.

The presidential social-distancing guidelines, which were announced March 16, were helpful. They include avoiding nonessential travel and eating out, as well as avoiding gatherings of more than 10 people. But last week’s open-by-Easter announcement suggested wrongly that the epidemic would be under control by the holiday.

The month ahead is critical in containing the virus, and everyone needs to help by staying home to break the chain of infection. Trump should keep pounding on the presidential bully pulpit. Given the bitter political divisions in this country, some will need to hear the message directly from him.

Sadly, it’s not difficult to find examples of those still not taking COVID-19 seriously. Spring-break revelers from across the country jammed Florida beaches this month. There’s video of a church in that same state still gathering worshipers together. With COVID-19 symptoms appearing from two to 14 days from exposure, we are just beginning to learn what role this recklessness is playing in the disease’s spread.

But a cluster of cases in Mount Vernon, Wa., previews the price for underestimating risk. Members of the Skagit Valley Chorale group decided to go ahead with practice at a local church on March 10. While Seattle was a hot zone about an hour’s drive south, Skagit County, known for its tulip farms, hadn’t yet had any confirmed cases.

Sixty members came and sang for two and a half hours. “Nearly three weeks later, 45 have been diagnosed with COVID-19 or ill with the symptoms, at least three have been hospitalized, and two are dead,” according to the Los Angeles Times.

In Minnesota, Gov. Tim Walz’s stay-at-home order went into effect Friday and continues through 5 p.m. April 10. Trump’s welcome new guidance underscores the prudence of the state’s move and signals the need to move with caution in the weeks after to contain this viral threat.