The coronavirus is not under control in much of the United States, according to a report by scientists at Imperial College London, who warn that the relaxation of blockages could lead to a new wave of deaths.
About half of all states still have reproduction rates greater than one, the report warned, which means that each coronavirus patient infects more than another. Any reproduction rate greater than one means that the virus is spreading exponentially.
The results come as almost all states and territories in the United States have begun to ease traffic restrictions, although many have not reached the milestones set by the United States Centers for Disease Control and Prevention to do so. . Robert Redfield, head of the CDC, told the Financial Times this week that he expects a second wave of cases this winter.
Axel Gandy, professor of mathematics at Imperial, said: “What this shows is that the epidemic has not passed. The numbers have gone down and the efforts are paying off. But continued efforts are needed. “
The report estimated the reproduction rate in each of the 50 states, based on the number of reported deaths and mobility statistics measured by Google. He found that in half of them, the rate is probably more than one, with the highest rates recorded in states like Texas, Arizona and Colorado.
The imperial model is used by New York to track the spread of the virus across the state. It shows that New York, which has been hit harder by the disease than any other state, initially had a reproductive rate of around five, but is now significantly less than one.
It also models what would happen to daily death rates in different parts of the country if people returned to normal behaviors.
A return to 40% of previous mobility, for example, would mean that deaths in New York would most likely return to the previous peak of around 1,000 per day and could reach 3,000. The same phenomenon could occur in Florida, warned the report, where the previous peak was around 80 deaths a day.
Gandy said these figures could be lower if people’s behavior changes during their trip, for example by wearing masks, keeping their distance from other travelers and washing their hands frequently.
But he added, “It could be a very big mistake if you relax too much. We have to keep the number R below one, and for now, it seems that most states are not far below. “
The results will reinforce the warnings issued by many public scientists in the United States about the loosening of restrictions.
Speaking to members of Congress last week, Anthony Fauci, one of the most experienced scientists in the White House coronavirus task force, warned of “suffering and death” if states released their brakes too quickly.
Donald Trump, the American president, however, pushed state governors to start reopening their economies as soon as possible, with most starting to follow suit. Oklahoma, for example, has reopened its nightclubs; Florida has reopened its gymnasiums.
Trump has denounced the warnings from health experts in his own administration, saying, for example, that Dr. Fauci’s warnings show that he is trying to “play from all sides”.
Nevertheless, Redfield said he expects a new wave of US infections later this year as the virus is re-imported from the southern hemisphere.