New statistical models of COVID-19 cases in Virginia show calls for social distancing and closing of public places has slowed the spread of the disease and could push the pandemic’s peak into the summer.
The models, designed by the University of Virginia Biocomplexity Institute, in cooperation with other agencies across the country, show that continued social distancing measures could lower the peak number of cases and keep hospitals from being overwhelmed by COVID-19 patients.
The models show that keeping the restrictions in place until June 10 could push the peaks into late July or August.
Gov. Ralph Northam touted the new models in a news briefing on Monday and said he plans to continue ordered closings for some businesses. He said the restrictions could be expected to continue for the near future.
Bryan Lewis, a professor and researcher with the UVa institute, said statistics related to cellphone tracking and other information gathered by Google and Cuebiq, which store and tabulate data, show Virginians largely have been following orders.
Lewis discussed the model and how it works during an hour-long video briefing prior to Northam’s update.
According to the data, Google reported a 44% decrease in retail and recreation use among Virginians, an 18% drop in trips to grocery stores and a 39% decrease in travel to workplaces. Cuebiq showed a 50% reduction in individual travel compared with last year’s average.
The Virginia-based model shows the efforts have reduced the number of virus cases and decreased the number of people one person with the virus on average would infect.
That should ease the threat of overwhelmed hospitals, officials said.
“Our social distancing efforts seem to be working. Under these current conditions, Virginia, as a whole, should have sufficient medical resources for at least the next couple of months,” Lewis said. “Other things the model shows us is that lifting social distancing restrictions too soon, without alternative ways to address and contain the infection, may lead to a quick second-wave [of cases].”
Northam cited the models in the later COVID-19 briefing as a reason for extending social distancing requirements. There was some confusion among business owners and state officials if the restrictions on certain businesses such as hair salons, barber shops and recreation-related businesses would expire April 23 or June 10.
“As of right now, we’re looking at our [COVID-19] peak being the latter part of April or early part of May and we will extend that order for people not to go into businesses and for those businesses to be closed,” Northam said, speaking specifically of recreation, restaurants, hair salons and other areas of public gathering.
“I know businesses need to know [the dates]. I know it will need to be extended, but I don’t know for how long,” he said. “I’ll make that announcement on Wednesday.”
COVID-19 is the disease caused by the SARS-CoV-2, a previously unknown virus that jumped from infecting animals to humans. Because humans have no immunity to the virus, there is no vaccine or treatment known for the disease it causes.
COVID-19 cases can range from extremely mild to where the person infected feels no symptoms, to high fevers, pneumonia and extreme fatigue. The disease can result in acute respiratory distress syndrome, which occurs when fluid builds up in the tiny, elastic air sacs, or alveoli, in the lungs. The fluid keeps the lungs from filling with enough air, which means less oxygen reaches the bloodstream, depriving organs of the oxygen they need to function.
Often a mechanical breathing device, a ventilator, is needed to prevent a person from dying from the syndrome. COVID-19 can cause a sudden spike of people suffering the syndrome and overwhelm hospitals with more patients than ventilators.
Models before social distancing was put in place in March indicated that Virginia’s patient peak would be later this month or early in May. The UVa model, which uses similar data-generation techniques as models the agency has created and implemented for the U.S. Department of Defense, predicts the peak in July or August, providing the state continues to keep stay-at-home orders in place until June 10.
The longer the orders are in place, the lower the peaks and the further into the summer the peak occurrence is postponed, the models show.
Lewis likened the social mitigation steps to driving a car on the freeway. Having no restrictions and letting the virus take its course is like “pressing the pedal to the metal.”
Some efforts at social distancing are like slowly accelerating, he said. To pause the growth — as the models show current efforts have done — is like putting the virus on cruise control so that cases grow, but at a slow and steady rate.
“We are at a cruising speed, you’re on the cruise control, you’re at a steady speed and you will get there when you get there,” he said.
Lewis said the models show that each person infected with the virus before March 15 likely infected an estimated 2.2 people. That number dropped to 1.1 people infected by each infected person after social distancing rules were laid out.
Because the models are based on Virginia statistics at the municipal level and upward to the state level, the models provide better information for setting state policies, said Virginia’s secretary of health and human resources, Dr. Daniel Carey.
“We can use these models to form general conclusions to help the governor make policy decisions,” he said. “Social distancing is important and it’s working in Virginia. We’re in it for the long haul and we need Virginians to keep working with us on this.”
During his briefing, Northam said the information supports keeping social distancing restraints in place.
“If we lift the stay-at-home order too soon, if we try and rush to get our lives back to normal, the number of cases will spike higher and earlier. We can’t afford that. We need to keep doing what we’re doing.” Northam said.
“I know it can feel like we’ve already endured the restrictions brought by this epidemic for a long time and we are going to need to keep living this way for the near future,” he said. “The key is to keep doing what we’re doing. Stay home, stay away from groups and wash your hands.”