A performance of a musical in New York City was canceled 30 minutes before show time on Wednesday after coronavirus infections were confirmed among vaccinated members of the company.
Disney Theatrical, the producer of "Aladdin," said breakthrough COVID-19 cases had been detected.
The musical had just reopened on Tuesday, following an 18-month shutdown due to the pandemic.
Disney Theatrical said performances would resume on Thursday as other staff had tested negative.
Broadway theaters are taking strict anti-infection measures, such as vaccinating performers and staff members and conducting regular testing.
They also ask audience members to show proof of vaccination before entering the venue.
US media say this is the first cancellation of a Broadway show linked to coronavirus infections since live performances in the entertainment district resumed on September 14.
They say the entertainment industry is facing difficulties as it tries to regain momentum.