TUESDAY, Nov. 24, 2020 (HealthDay News)

The number of confirmed COVID-19 cases in the United States is likely to nearly double before President-elect Joe Biden’s inauguration, researchers warn.

Cases could rise from 11.4 million to 20 million by the end of January, according to a study published Nov. 23 in the journal Scientific Reports. Of course, counts vary day to day — as of Tuesday, for example, there were 12.4 million cases of COVID nationwide, according to Johns Hopkins University.

For the new study, researchers from Washington University in St. Louis developed a model that had accurately predicted the rate of COVID-19 growth in the United States over the summer.

“One of the key reasons for the increased accuracy of this model over other COVID-19 forecasts is that this model accounts for the fact that people live in interconnected social networks rather than interacting mostly with random groups of strangers,” said study co-author Raphael Thomadsen, a marketing professor.

“This allows the model to forecast that growth will not continue at exponential rates for long periods of time, as classic COVID-19 forecasts predict,” he added in a university news release.

The model shows how different levels of social distancing affect the spread of COVID-19. The prediction of 20 million cases before January’s end is based on current social distancing measures, which reflect a 60% return to normalcy.

“Even small increases in social distancing can have a large effect on the number of cases we observe in the next two and a half months,” Thomadsen said. Resuming a 50% return to normalcy — the average level of distancing in early August — could result in 5 million fewer cases by January’s end.

“We could effectively squash out the COVID growth within a few weeks if we went back to the levels of social distancing we experienced in April,” he said.

The researchers also noted that due to increased testing and the upcoming holidays, their model may underestimate end-of-January cases.

“In our model, we assume that only 10% of cases are ever diagnosed, meaning that we will start to hit saturation,” said study co-author Song Yao, an associate professor of marketing.

“However, more recently, testing has increased, and probably more like 25% of cases are diagnosed. In that case, total COVID cases would increase beyond 20 million in the next few months unless we, as a society, engage in more social distancing,” he added.

The upcoming holidays will present great uncertainty to the outlook as people travel more at the end of the year, said co-author Meng Liu, an assistant professor of marketing. This can increase the potential for more cases, and “will likely make our forecast an optimistic one,” she added.

More information

The U.S. Centers for Disease Control and Prevention explains how to protect yourself and others from COVID-19.

SOURCE: Washington University in St. Louis, news release, Nov. 20, 2020

Robert Preidt

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