Study Show Us What Works—and What Doesn't—in Curbing COVID-19

Intense social distancing measures—like lockdowns and school and business closures—have been widely used in the United States in response to the COVID-19 pandemic. Researchers are now examining whether there are less socially and economically disruptive ways to combat a possible resurgence.

Researchers from the University of Georgia’s Center for the Ecology of Infectious Diseases and College of Public Health explored how math can help us better understand what has (and has not) worked during the COVID pandemic.

They found that the alternatives to strict lockdowns—widespread testing, contact tracing, quarantines, certification for non-infected people, and other public health policy measures—can slow the spread of the virus when combined, but only with significant investments and wide compliance.

Analyzing Our Response to the Pandemic

The study used mathematical modeling to provide some answers on how well alternatives to strict social distancing work. “Our big idea working on this study was that we should look at all possible strategies, all the strategies on the table when we're responding to a pandemic," study co-author Kyle Dahlin, PhD, a postdoctoral associate with the center, tells Verywell.

The research divided various strategies into two categories—targeted and generalized—and different combinations were tested.

Targeted strategies were those typically applied to specific people in the public, likely based on their COVID-19 infection or exposure status. Some of these include:

• Isolation and contact tracing
• Quarantine and symptom monitoring
• travel restrictions

The second category, generalized strategies, encompasses interventions that are applied broadly across a large number of people. This can include actions like school closures, physical distancing, lockdowns, and wearing masks.

What Worked?

The mathematical model indicated that when only intensive social distancing measures were used after the start of the first wave of the pandemic, about half of the population eventually became infected.

When intensive social distancing was combined with general interventions—such as mask-wearing, hand hygiene, contactless shopping, and keeping to within a small group (micro-distancing)—transmission of the virus slowed. However, the pandemic was still not completely suppressed.

The authors of the study concluded that "generalized protective measures such as wearing face masks, improved hygiene and local reductions in density are found to significantly increase the effectiveness of targeted interventions."

Identifying Active Infections

The targeted and generalized approaches can both be effective, but they each require extensive rapid testing for the virus.

The mathematical models revealed that about 95% of actively infected people had to be identified to stop the spread of the virus. When active case identification was combined with face masks and hand hygiene, the percentage of active cases that needed to be identified dropped to 80%.

However, the authors noted that during the first wave of the pandemic, just 1% to 10% of cases were being identified—which means the strategy would not have worked.

“Our findings show that those precautions taken by individuals are incredibly important for suppressing outbreaks in the broader population,” Dahlin says. “If those sorts of practices are maintained, not only do they themselves have a large effect on reducing outbreak sizes, but they amplify the effects of any of these strategies.

Interventions Still Make a Difference

"It's much harder to effectively implement these strategies without generalized interventions," Dahlin says. "If we could have maintained that intense level of social distancing for longer, on the order of a year, we predict that we would have had a much smaller outbreak altogether."

One of the most important interventions— the widespread use of vaccines—was not evaluated in the study because no vaccines against COVID-19 were available when the mathematical modeling was being done.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.