McCartney, who is being treated in a Tokyo facility, "will make a complete recovery and has been ordered to take a few days' rest," publicist Stuart Bell said in a statement released Thursday.
"Paul has been extremely moved by all the messages and well wishes he has received from fans all over the world."
The viral infection had already forced the iconic rocker and former Beatle, who will turn 72 on June 18, to miss four Japanese concerts, part of his current Out There tour.
On Wednesday, his representatives added a date next week in Seoul — which would have been his first concert in South Korea — to the cancellations.
The self-taught singer, musician and composer rarely cancels concerts.
"I'm sorry to be letting fans down. I'm very disappointed by this and hope to be able to visit soon," he said in a statement issued Wednesday.
The cancelled Asian leg of McCartney's world tour follows recent dates in South America. He had been scheduled to continue with further concerts in the U.S. in June through August.
McCartney and drummer Ringo Starr, the two surviving members of the Beatles, were widely celebrated in February for the 50th anniversary of the influential rock band's North American debut.