AUGUSTA, Maine (AP) Maine Senate President Troy Jackson has tested positive for COVID-19, becoming the highest-ranking official in state government to contract the virus.

Jackson, who is fully vaccinated, said he is isolating after testing positive in Augusta. He said he is not experiencing symptoms but decided to undergo a rapid test after learning a close contact had the virus.

“While breakthrough COVID-19 infections are far more rare, we know that they are possible. More and more breakthrough infections continue to be reported all across the state and country due to the highly contagious delta variant,” Jackson, D-Allagash, said Tuesday evening in a statement.

He said he was grateful to be vaccinated since vaccines have proven to be effective in preventing severe symptoms and hospitalizations.

Jackson is the highest-ranking state official to contract the virus and is one of several state lawmakers to test positive.

U.S. Sen. Angus King of Maine also experienced a breakthrough infection and has since recovered.