Julio Montoya (right) checks his phone while waiting for the bus outside the City Hall in San Jose, Calif., on Oct. 6, 2021. (Harika Maddala/ Bay City News)

Mask requirements for public transit and airplanes will remain in effect through at least May 3, the U.S. Centers for Disease Control and Prevention announced Wednesday.

The nationwide mandate had been set to end April 18, but federal public health officials said they would extend the expiration date by roughly two weeks to allow more time for the study of the omicron subvariant BA.2.

“CDC will continue to monitor COVID-19 levels, in our communities, nationally, and abroad to provide the most up-to-date guidance to keep travelers safe and healthy,” the CDC said in a statement.

The BA.2 variant of omicron now makes up more than 85 percent of COVID cases in the U.S., growing roughly 80 percent faster than the original omicron variant that drove the winter surge.

In a statement on the subvariant released in February, officials with the World Health Organization said that while BA.2 may be more transmissible than the main omicron variant, the gap between the two is not as wide as the difference in virulence between omicron and the delta variant.

“Further, although BA.2 sequences are increasing in proportion relative to other Omicron sublineages, there is still a reported decline in overall cases globally,” the WHO said.

Research is ongoing regarding how potent the subvariant is or the risk of reinfection it may present.

The subvariant has been detected in multiple Bay Area counties, including Santa Clara and Contra Costa.