Vaughan has made 19 appearances in Super League so far for St Helens and Salford, having joined the latter on loan earlier this season.
The 21-year-old can play at either centre or as a back row forward and has scored two tries in 11 games this campaign.
Winger Sambou scored on his Super League debut for St Helens in March in the defeat by Warrington.
The 20-year-old has played five matches this season, having spent much of 2024 on loan in League 1 as he returned from injury.
“I know they’re coming to work hard, I know it’s taken a lot of courage on their part to make the move but myself and the players and the staff are looking forward to welcoming them both for next season,” head coach Matt Peet told Wigan’s website., external
