The CDC confirmed that Ira Longini, professor at the Center for Statistics and Quantitative Infectious Diseases at the University of Florida, is a “funded partner.” The agency said he works with them on Covid-19 modeling.
Modeling is not precise, and uses known data to project trends in disease spread, and there were dissenting opinions expressed to CNN about Longini’s analysis. Yet two other disease experts broadly agreed with the estimate.
Longini said: “I would guess the US will hit a peak in deaths in the next two-three weeks, as the doubling time seems to be about two-three days.” He added: “Maybe a partial lifting of the shelter-in-place for those less vulnerable may make some sense, in about three weeks. By then, much of the damage will have been done.”
Two experts agree
Dr. William Schaffner, an infectious disease specialist at Vanderbilt University, said the peak might take three more weeks.
“My notions are harmonious in that I also anticipate … (the next) three to six weeks will be critical here in the United States,” he said. He added it might take six weeks as the US is a “very diverse country with a hot spot in New York right now and warm spots. The rest of the country is warming up. In the next three to six weeks, all those areas will start to surge or will have their curve depressed or blunted by the social distancing that’s going on. The virus will tell us.”
A second expert agreed broadly. Dr. Arnold Monto, a professor of epidemiology at the University of Michigan School of Public Health, said by email: “I agree that by 3 weeks, we will have a better idea of what is going to happen going forward. The outbreaks seem to be hitting different communities at different times and at different intensities, so it is hard to generalize However, I agree in general. And that is why action now in terms of social distancing is so important.”
Epidemiology has informed US, UK and other government policy as it provides informed guesses as to where and how fast infections are spreading. A recent sharpening of US and UK restrictions was, for example, based on modeling from the UK’s Imperial College, which significantly worsened its prediction of how many people would require intensive care in hospital, using data from Italy.
Peak is ‘impossible to predict,’ another expert says
One disease modeler said it was “impossible to predict” when the peak would hit.
Dr. Stefan Flasche, a disease modeler at The London School of Hygiene & Tropical Medicine, told CNN by email the peak was influenced by the efficiency of lockdown measures, and “may be anywhere between some time very soon and not for another few months.”
Erin Strumpf, a professor of economics at McGill University, told CNN: “Nothing suggests that we could just ‘snap back’ to life as it was before. We’re taking concrete actions to lower the probability of an uncertain outcome.”
She cautioned that it’s hard to put a price on the uncertainty — and deaths — that might occur were the government to begin loosening restrictions. “Markets, investors, and economies don’t do well in the context of panic and uncertainty,” she said. “The people that are going to be dying from coronavirus are going to be very visible. We are going to know exactly who those people are. That changes the discussion a lot.”