The Centers for Disease Control and Prevention increased the severity of its warning against cruise ship travel.

The Level 4 warning is the agency’s strongest recommendation against cruise travel. It means there is a “very high level of COVID-19” aboard cruise ships and that all people should avoid cruise travel worldwide.

The increase comes a month after the CDC lifted its 7-month ban on cruise ship travel and released its plan for the industry to resume safely.

The cruise industry creates tens of thousands of jobs in Alaska and was anticipated to generate hundreds of millions of dollars in spending to the state this year.

Cruising has been suspended since mid-March. The closure of Canada’s ports is among the reasons Alaska’s cruise season was canceled this year. That closure will remain in effect until at least February.