UCLA Researchers Say Physical-Distancing Measures, if Relaxed Too Soon, Might be All for Naught

If physical-distancing measures in the United States are relaxed while there is still no COVID-19 vaccine or treatment and when personal protective equipment remains in short supply, the number of resulting infections could be about the same as if distancing had never been implemented to begin with, according to a UCLA-led team of mathematicians and scientists.

The researchers compared the results of three related mathematical models of disease transmission that they used to analyze data emerging from local and national governments, including one that measures the dynamic reproduction number — the average number of susceptible people infected by one previously infected person. The models all highlight the dangers of relaxing public health measures too soon.

“Distancing efforts that appear to have succeeded in the short term may have little impact on the total number of infections expected over the course of the pandemic,” said lead author Andrea Bertozzi, a distinguished professor of mathematics who holds UCLA’s Betsy Wood Knapp Chair for Innovation and Creativity. “Our mathematical models demonstrate that relaxing these measures in the absence of pharmaceutical interventions may allow the pandemic to reemerge. It’s about reducing contact with other people, and this can be done with PPE as well as distancing.”

The study is published in the journal Proceedings of the National Academy of Sciences and is applicable to both future spikes of COVID-19 and future pandemics, the researchers say.

Bertozzi is also a distinguished professor of mechanical and aerospace engineering. Elisa Franco, a UCLA associate professor of mechanical and aerospace engineering and bioengineering, is one of the study co-authors.

The full UCLA Newsroom article can be found here.