Just a few weeks ago, Kem Kemp, a high school teacher in Houston, knew no one personally who had tested positive for the coronavirus. Then her roommate came down with a deep cough and was diagnosed with Covid-19.

Her brother, a dentist in Amarillo, Texas, also tested positive. A neighbour fell sick with the virus. Two faculty members at the private school where she teaches were required to quarantine. And in the last few days, so were two of the students she advises.

“Before, we were watching the numbers on the news,” said Kemp, 62. “Now it’s started creeping into my neighbourhood, my school, my home — right where I’m existing.”

As Covid-19 cases surge in almost every part of the country, researchers say the US is fast approaching what could be a significant tipping point — a pandemic so widespread that every American knows someone who has been infected. But, as reflected in the polarised response to the virus, the public remains deeply divided about how and whether to fight it, and it is unclear whether seeing friends and relatives sick or dead will change that.

Many who have seen people close to them seriously affected say they are taking increased precautions. Others, though, are focusing on how most people recover and are shrugging off the virus — and calls for concerted efforts to combat it.

The US surpassed 11 million reported virus cases on Sunday, with one million of those tallied in just the last week. The daily average of new cases is up by 80 per cent from two weeks ago. More than 69,000 people were in American hospitals with Covid-19 on Saturday; more than 1,100 deaths are being reported each day on average.

Those alarming numbers — the highest case numbers and death toll in the world — underscore a reality found in small towns, big cities and sprawling suburbs alike: The coronavirus has become personal.

Researchers estimate that nearly all Americans have someone in their social circle who has had the virus. About a third of the population knows someone — from a close relative to a neighbour to a co-worker to a friend of a friend — who has died from the virus, researchers say.

But not everyone is hunkering down in fear or taking precautions as simple as wearing a mask.

“As more and more people know someone who gets sick and dies, more and more Americans are likely to take this disease seriously,” said Nicholas A. Christakis, a Yale sociologist and the author of Apollo’s Arrow, a new book about the impact of the virus. “But the effect of knowing people who survived it may lead people to misread Covid as not being as bad as it is.”

Kemp, for one, has become more vigilant since listening to her roommate cough herself to sleep at night. She wears a mask when she walks her dog, and notices when others do not. Wessie and John Dietz, of Sauk County, Wisconsin, wear masks even in their car since their 20-year-old grandson, an electrician’s apprentice, appeared to have contracted the virus from a friend he took a ride with. “I hadn’t even thought about it before that,” Dietz said.

And April Polk, of Memphis, has urged all young people to follow restrictions to curb the spread of the virus since her 24-year-old sister, Lameshia, died this summer.