Republican U.S. Sen. Roger Wicker of Mississippi has again tested positive for COVID-19, his office said Monday.

His communications director, Phillip Waller, said Wicker took a required test and received a positive result.

“He will be expected to miss votes and committee business this week until he is able to return in person to the Senate,” Waller said.

Wicker, 70, attended the World Economic Forum in Davos, Switzerland, in late May.

Wicker was also diagnosed with COVID-19 in August last year and in February this year. He said in February that he is fully vaccinated against the virus.

Wicker is the top Republican on the Senate Commerce, Science and Transportation Committee. On April 8, he joined several Republican senators and representatives in a letter urging the Biden administration to drop the federal mask mandate for airlines and other transportation services.

“The American people have seen through the false logic that COVID-19 only exists on airplanes and public transportation. They see it every day when they go to a grocery store, restaurant, shopping mall, or movie theater with no masks in sight, leading them to demand unneeded mandates come to an end,” the lawmakers wrote.

Later in April, federal officials stopped enforcing the mandate on airplanes after a federal judge ended the requirement for face coverings on planes and trains and in transit hubs.

About two weeks after his COVID-19 diagnosis in August, Wicker said he had received a clean bill of health and was ready to start traveling the state again.