The good news: The United States has a window of opportunity to beat back Covid-19 before things get much, much worse.

The bad news: That window is rapidly closing. And the country seems unwilling or unable to seize the moment.

Winter is coming. Winter means cold and flu season, which is all but sure to complicate the task of figuring out who is sick with Covid-19 and who is suffering from a less threatening respiratory tract infection. It also means that cherished outdoor freedoms that link us to pre-Covid life -- pop-up restaurant patios, picnics in parks, trips to the beach -- will soon be out of reach, at least in northern parts of the country.

Unless Americans use the dwindling weeks between now and the onset of "indoor weather" to tamp down transmission in the country, this winter could be Dickensianly bleak, public health experts warn.

"I think November, December, January, February are going to be tough months in this country without a vaccine," said Michael Osterholm, director of the Center for Infectious Diseases Research and Policy at the University of Minnesota.

It is possible, of course, that some vaccines could be approved by then, thanks to historically rapid scientific work. But there is little prospect that vast numbers of Americans will be vaccinated in time to forestall the grim winter Osterholm and others foresee.

Human coronaviruses, the distant cold-causing cousins of the virus that causes Covid-19, circulate year-round. Now is typically the low season for transmission. But in this summer of America's failed Covid-19 response, the SARS-CoV-2 virus is widespread across the country, and pandemic-weary Americans seem more interested in resuming pre-Covid lifestyles than in suppressing the virus to the point where schools can be reopened, and stay open, and restaurants, movie theaters, and gyms can function with some restrictions.