What a maddening, terribly complicated viral enemy is this coronavirus. In some it has seemingly no effect, meaning they can unknowingly transmit it to others, whom it may kill.

People sacrificed much to curb its spread. Businesses closed, some forever. People retreated to their homes, many divided from family and friends. In Connecticut, at least, the vast majority of us dutifully slip on our masks to shop, to work, to live some public life. It has become terribly routine.

But progress was made. The infection numbers came down. But the virus never disappeared.

It is relentless.

As businesses opened up, as people sought to live with more normalcy, to be social again, the virus seized the opportunity. Marginally at first, then rapidly. Testing positivity rates in Connecticut, which health officials would like to see at 1% or less, have for a couple of weeks now stayed at 3% and higher, reaching as much as 6.1%. Hospitalizations for COVID-19, which dropped to a nadir of 68 on Sept. 20, have increased about 500% since, approaching 350 at week’s end.

Still, Connecticut is doing better than much of the country. The United States is now experiencing the world’s greatest outbreak of coronavirus. The nation documented a record 121,000 new infections on Thursday, a day after hitting 100,000 for the first time since the start of the pandemic. And, health officials say, a multitude more people are infected than the testing numbers reveal.

More than 236,000 Americans have died, and the number of confirmed infections is fast approaching 10 million.

Back in April, Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases, had expressed optimism Americans would get a handle on the outbreak.

“The real data are telling us it is highly likely we are having a definite positive effect by the mitigation things that we’re doing, this physical separation,” Fauci said in an NBC interview. “I believe we are going to see a downturn … and it looks more like the 60,000 (deaths), than the 100,000 to 200,000” projected fatalities.

If only.

Responsible governors — Connecticut Gov. Ned Lamont among them — have tried to fill the gap created by the lack of any clear and sustained plan to curb the virus by the Trump administration. On Thursday, Lamont announced new restrictions.

No more than 10 people can gather for indoor or outdoor events.

“It’s those informal, private gatherings where we’re seeing the ignition taking off in terms of the infection rate,” said Lamont in explaining his decision.

Restaurants must reduce their capacity from 75% to 50%, with no more than eight people at a table.

This is a beautiful, unseasonably warm weekend. But such days are numbered. Cold weather will soon drive us indoors. The virus thrives and spreads among people indoors. If the governor’s latest steps do not arrest the increase in infections and hospitalizations, he must be prepared to order a return to the stringent lockdown seen in the early days of the pandemic.

And, with the holidays fast approaching, families face tough decisions. The governor conceded that when it comes to family and other private gatherings, people will be operating “on the honor system.” COVID police won’t be breaking down doors and counting heads during the turkey feast.

People, after so much isolation, are longing to bring loved ones near to celebrate Thanksgiving, Christmas, Hanukkah, and other traditions. Folks have to be smart about it. Skipping gatherings or making them virtual is the safest course. Keeping get-togethers small, with people you regularly interact with, is low risk. But introducing more people, from more places, spikes the risk of transmission, not only to the holiday celebrants, but to the greater community.

“Thanksgiving: 10. That dinner party: 10,” said Lamont.

This is going to be hard. But letting this pandemic spin further out of control would be much harder.

The Day editorial board meets with political, business and community leaders to formulate editorial viewpoints. It is composed of President and Publisher Timothy Dwyer, Executive Editor Izaskun E. Larraneta, Owen Poole, copy editor, and Lisa McGinley, retired deputy managing editor. The board operates independently from The Day newsroom.