Based on simulations of the coronavirus outbreak’s future course, Harvard scientists say prolonged or intermittent social distancing may be necessary into 2022 — but they stress that research into how long immunity to the virus lasts will be urgently needed to refine their projections.

The computer simulations, described in a study published online today by the journal Science, assume that the patterns of transmission for the coronavirus behind COVID-19 lie somewhere between the common cold and pandemic flu. The models show periodic upswings in the virus’ spread, on time scales that are determined by immunity.

To keep those upswings within the capacity of hospitals to handle serious cases of COVID-19, surveillance measures and social distancing may have to be used on a sustained or periodic basis, the scientists behind the study say. Such measures will buy time for the development of new treatments and vaccines.

“We do not take a position on the advisability of these scenarios given the economic burden that sustained distancing may impose, but we note the potentially catastrophic burden on the healthcare system that is predicted if distancing is poorly effective and/or not sustained for long enough,” the researchers write. They say the virus could be effectively eliminated after an outbreak if immunity is permanent.