Here we mask again.

If you’re heading to Dana-Farber Cancer Institute, you’ll have to wear a face mask after the cancer center reinstituted a mask mandate — as COVID cases spike and respiratory infections jump across the area.

The Boston-area COVID wastewater data has been surging, and reported COVID cases climbed more than 20% across Massachusetts in the last week. Meanwhile, a new variant called JN.1 is quickly spreading.

“Face masks are currently required for everyone at Dana-Farber, including staff and patients, due to higher rates of respiratory illness in our region,” Dana-Farber said in a statement.

The mask mandate “will continue for the foreseeable future,” the cancer center added.

“We will continue to monitor levels of respiratory illness in the community and adjust our policy when appropriate,” Dana-Farber added. “We check a number of different data points, including rates of influenza-like illness, staff absenteeism, and emergency room visits and hospitalizations caused by respiratory viruses. We will lift the mask requirement when these data points remain consistently lower.”

Those with cancer have a higher risk of suffering from severe COVID. Other factors that increase the risk for severe COVID include having a weakened immune system, older age, and other medical conditions.

As reported COVID cases go up in the region, the new variant JN.1 has been declared a variant of interest by the World Health Organization.

People who have not received the latest COVID booster should consider getting it right away, said Davidson Hamer, a Boston University School of Public Health infectious diseases specialist.

“And anyone who is at increased risk of severe disease and possible hospitalization should wear masks in public places, such as public transportation and crowded stores to reduce their risk of exposure,” Hamer added.

“Similarly, rapid at-home tests should be used if symptoms develop,” he said. “And anyone who is at higher risk and who tests positive should immediately contact their physician since the early initiation of oral antiviral drugs can reduce the risk of progression to severe disease and the need for hospitalization.”

Every home in the U.S. is eligible to order four free at-⁠home COVID tests at www.special.usps.com/testkits.

The Massachusetts Department of Public Health on Thursday reported that there were 5,441 confirmed and probable COVID cases last week, a 21% increase from the previous week. The weekly case total at the beginning of November was 2,120 infections.

This week, 15.7% of emergency department visits in the state were due to acute respiratory disease.