In the Philadelphia jail, the number of COVID-19 cases has tripled in the last two months. In Chicago’s lockup, infections have increased 11-fold in the same period. And in New York, city jails are struggling with a mushrooming 13-fold increase in less than a month.

From local lockups in California to prisons in Wisconsin to jails in Pennsylvania, COVID-19 is once again surging behind bars, posing a renewed threat to a high-risk population with spotty access to healthcare and little ability to distance.

At this point it’s unclear whether the surge in infections is due to the highly contagious omicron variant. Still, as caseloads across the country skyrocket and omicron becomes the dominant variant, experts worry the coronavirus is once again poised to sweep through jails and prisons. As in the world outside prison bars, many incarcerated people are struggling with pandemic fatigue. They’re also facing uncertain access to booster shots, widespread vaccine hesitancy and pandemic-driven staffing shortfalls that have created even harsher conditions.

As with previous iterations of the virus, everything about prisons and jails makes them a setup to magnify the harms of omicron. “The overcrowding. The poor sanitary conditions. The lack of access to health care,” said Monik Jimenez, an epidemiologist at Harvard’s School of Public Health. “Masking is only going to do so much when you have people on top of you.”

Though scientists warn that the new variant is far more contagious than previous ones, a half dozen prisoners who spoke with The Marshall Project for this story said they hadn’t noticed any widespread concern about it at this point and that prison officials had given them little information.

Read the full article about Omicron preparation by Beth Schwartzapfel and Keri Blakinger at The Marshall Project.