"Senator Wicker tested positive this morning for the COVID-19 virus after immediately seeking a test due to mild symptoms," his office said in a statement.
Wicker, 70, was already fully vaccinated against the coronavirus and remains in good health, the statement added.
King, 77 announced in a later statement that he had tested positive for the coronavirus. The senator said he was tested after not feeling well on Wednesday.
Hickenlooper, 69, said in his statement that he felt good but was isolating himself as his doctors had instructed.
“I've tested positive for a breakthrough case of COVID-19. I feel good but will isolate per docs instructions. I’m grateful for the vaccine (and the scientists behind it!) for limiting my symptoms,” he said in a Twitter message.
In all, 131 representatives and senators have either isolated themselves because of having COVID-19, self-quarantined after exposure, or they took other action or no action after exposure, the GovTrack.com web site said.