There's a lot we don't know. That's just how it goes with a novel virus — one no one's ever seen before, one no one's ever built up antibodies against.

And that's how it goes with an unprecedented effort to get most of the state staying at home most of the time, to curb it.

But state officials Monday put the finest point to date on when they expect New Jersey would have run out of hospital beds, out of ICU beds and out of ventilators had nothing been done to slow the spread of COVID-19, and had nothing been done to ramp up health system capacity.

Wednesday, April 1. Two days from now. That's when Gov. Phil Murphy and Health Commissioner Judith Persichilli say New Jersey would have run out of ICU beds, using the COVID-19 Hospital Impact Model for Epidemics pioneered by Penn Medicine.

That's when New Jersey's health system would have started to get overrun.

"It is our best understanding of how fast COVID-19 would have spread across our state without social distancing," Gov. Phil Murphy said Monday. We're about 10 days out from when New Jersey would have run out of hospital beds overall, he said.

By the start of May, under that model, New Jersey would have needed 40,000 ICU beds — and only normally has about 1,000. Double the capacity, if hospitals start using other beds for ICU care, and you still come up 38,000 short.

But that's not the circumstance before us — New Jerseyans have been operating under strict orders to work from home if possible. Most forms of retail are closed. Those businesses that can operate are restricted in how they do so — like restaurants, only able to offer take-out dining.

Social distancing, as we've all come to know it, is the best and only tool we have to slow the spread and give the health system time to absorb its impact, Murphy has repeatedly said. State officials worry an unmitigated onslaught of COVID-19 patients wouldn't only be shut out of necessary care themselves, but would make it impossible for hospitals to treat other patients in urgent need adequately.

It's not clear just how strong compliance with the social distancing measures is, but Persichilli guestimated the number at 40 to 45 percent Monday. She said with 50 percent, New Jersey could weather the expected surge of coronavirus patients even with existing hospital capacity. State officials are working with a more conservative estimate of 31 percent, based on past social distancing efforts in past epidemics.

With that, New Jersey would still fall short — running out of ICU beds on April 11 and hospital beds entirely on May 8, state officials said. By around the start of June, we'd need twice as many beds as we have.

"This assumes that we've done nothing to increase capacity," Persichilli said.

David Matthau / Townsquare Media

But New Jersey has been undertaking a herculean effort to do just that. Three FEMA-backed field hospitals are expected to open in the coming weeks — the first, in Secaucus, by the end of this week. Hospitals are being asked to double their ICU capacity by repurposing other beds and equipment. Closed hospitals are set to reopen to help accommodate the surge. Dorms and hotels will be used for medical care as needed.

Persichilli said to expect New Jersey's permanent hospitals to essentially become all-out intensive care operations. Less critical needs will be served by the spillover into the temporary facilities.

There are a lot of assumptions worked into the models.

They assume coronavirus infections in New Jersey will double every six days — a hard number to pin down with only symptomatic people being tested, but one that seems to track with trends seen so far. They assume about 5 percent of patients will need to be hospitalized for some length of time. They assume 2 percent will need ICU care. The models put the average hospital stay at a week, and the average time in the ICU at nine days. A given ventilator patient is expected to need the device for nine days as well.

They assume that every current COVID-19 case under investigation — but not yet with a test result back — comes up positive.

And they're a point-in-time calculation. Run the numbers again tomorrow, you'll get different results.

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So, assuming all of that, and assuming at least that 31 percent compliance, and assuming all goes to plan with expanded capacity, Persichilli said New Jersey can weather the coming surge. That's in part due to a current ban on elective surgical procedures freeing up more space, she said.

"If we were doing nothing with our hospitals, no planning, we would be short," she said. In a press conference Monday, she didn't put an exact total on the beds or resources that will be available after the several efforts to ramp up are complete.

Murphy said New Jersey most desperately needs ventilators. It has about 2,000 on hand and is hoping to double the number, state officials have said. They're working with FEMA and other authorities to allow two people to share one in an emergency while supplies ramp up, and to repurpose similar equipment. That "buys precious time," Murphy said.

Federal authorities are sending New Jersey a supply of 300 from the national stockpile, he said. Murphy said he's grateful to the Trump administration for the support, "but to be absolutely clear, this is far, far from what we will ultimately need."

"This is our concern No. 1," he said.

Even so, Persichilli said, New Jersey ultimately expects New Jersey to have enough ventilators on hand. A medical team from FEMA is coming to New Jersey this week to work with the New Jersey Hosptal Association and train physicians on co-venting.

“Apparently the efficaciousness is similar," she said.

She also said switching a valve on anesthesia machines can convert them to ventilators, so the state Health Department is collecting data on how many of these machines are in nearly 1,000 ambulatory surgery centers and hospital operating rooms across the state.

“We have thousands of anesthesia machines so we have backup,” she said. "We are definitely going to be preparing for the worst. We’re hoping for the best. Ee’re just going full speed ahead to make sure if we need it, we will know about it.”

Persichilli said Monday she's much more worried about personal protective equipment — like effective masks and gowns — though Murphy has outlined several efforts from private industry to step up with donations.

"Do we have enough PPE?" Persichilli said. "The answer's no, and we know that. We haven't had enough PPE for a long time.

And it's not clear New Jersey will have enough medical personnel to go around, though it's recruiting volunteers. Rutgers is sending its medical students out into the field early to help.

"From the workforce perspective, that's the thing that's concerning," Persichilli said.

Murphy said so far, New Jersey has had 3,611 individuals respond to the call.

Monday, state officials counted another 3,347 novel coronavirus cases, bringing the state's total to 16,636. The state counted another 37 deaths, bringing the total to 198.

— Includes reporting by David Matthau

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