Vaughan was among a host of former players who suggested that Cook should be replaced as Test captain.
"No question, I was wrong. Two and a half weeks ago, I said a break would've done him good. But the England and Wales Cricket Board stood by him, he was strong and said: 'I'm the man to carry this young team forward'," Vaughan told BBC Radio 5.
A determined Cook responded to his criticism with scores of 95 and unbeaten 70 in Southampton. .
"I think that one catch is the real twist of the whole series. If Jadeja had caught Cook on 15, I really felt at that time, it would've been a disaster for the side," he said.