The Transportation Security Administration said, Friday, that passengers on aircraft and other transportation in the United States will have to continue to wear face masks to prevent the spread of COVID-19 until at least September 13.

The mandatory mask use order, which went into effect on February 1, expired on May 11.

In announcing the extension, Darby Laguey, acting director of the agency, said that masks “remain an important tool for defeating this epidemic,” even though about half of American adults have already been vaccinated against the virus.

The rule requires all passengers to wear a face mask to help prevent the spread of COVID-19 throughout the nation’s transportation network. This includes airports, buses, and trains. Children under the age of two and people with certain disabilities are exempt.

Penalties for breaking the law range from $ 250 to $ 1,500 for repeat violators.

The Centers for Disease Control and Prevention said people who have already received doses of the virus vaccine can travel, but its guidelines will continue to require the use of a mask, maintaining social distancing, and other measures to avoid infection.