Carnival Corp.'s Cunard unit said on Wednesday its Queen Mary 2 cruise ship would skip a scheduled stop at New York and instead extend its stay in Barbados until Jan. 2 to bring in more staffers.

The company said its decision to add more crew members was a precautionary measure, but did not expand on why it needed more workers on the ship.

Queen Mary 2 is among the more than 85 ships the U.S. Centers for Disease Control and Prevention is investigating for onboard COVID-19 cases.

The spread of the Omicron variant has sparked fears that U.S. health officials may reintroduce a temporary ban on cruising, just months after U.S. cruise operators resumed guest operations.

The 28-night Queen Mary 2 ship left Southampton on Dec. 13 and will sail back to the United Kingdom after its stay in Barbados to ensure it reaches the British port city on Jan. 10 as planned.

Carnival said on Tuesday itineraries of most of its ships were unchanged but a few destination ports were reviewing their protocols and processes due to the fast-spreading new variant. Carnival U.S. shares fell nearly 1% before the bell on Wednesday.