HONOLULU (AP) — The Hawaii Department of Education will prohibit events involving gatherings of more than 20 people for the remainder of the school year.

The ban announced by the department Tuesday as a precaution against the coronavirus covers events scheduled through June 1, including banquets, May Day celebrations and proms.

The department said it would announce plans for limited in-person commencement ceremonies by Feb. 26.

School officials were encouraged to develop alternative ceremony formats, including drive-by and online festivities.

“We understand that these are significant and meaningful events to our students," education department Superintendent Christina Kishimoto said in a statement.

“This decision was made to avoid planning and financial hardships that schools and families would incur due to potential last-minute cancelations," Kishimoto said.

The cancelation of annual proms is also expected to impact businesses that provide dresses, tuxedos, flowers, limousines and hair and makeup services.

Jackie Segawa, co-owner of Do’s Formal, said the business will lose about 60% of its annual sales without the dances and is offering large discounts to stay afloat, selling some dresses for as low as $10.

“We’re doing the best we can just to generate income,” Segawa said.

Toko Sugaya, owner of Lidia Hawaii Dress Rentals, said she pivoted from marketing to Japanese tourists to serving locals in the hope that prom sales would help the business. Now she is left with racks of dresses and no customers.

Monty Pereira, Watanabe Floral sales and marketing director, said the company will instead focus on graduations.

“We’re preparing now to figure out a way to make this special for these kids,” Pereira said.

For most people, the coronavirus causes mild or moderate symptoms, such as fever and cough that clear up in two to three weeks. For some — especially older adults and people with existing health problems — it can cause more severe illness, including pneumonia, and death.