All three players were mainstays of the Arsenal Under-18s side that reached the FA Youth Cup semi-final last season, with Kamara and Moore also helping the under-19s to the quarter-finals of the UEFA Youth League.
Central midfielder Kamara was a regular for the Gunners' under-21s last season too, featuring 10 times. The tough-tackling 18-year old is a Finland youth international.
Moore, who turned 17 on Saturday, made eight appearances for the Gunners' second string in 2013/14. An England youth international, the right back won the European Under-17 Championship with the Three Lions this summer.
Vickers, 18, put in a string of fine performances in the FA Youth Cup last season, including a man-of-the-match display against Charlton Athletic in the fifth round.
The boyhood Arsenal supporter also enjoyed a successful loan spell with Isthmian League Premier Division side Canvey Island in 2013/14.
Everyone at Arsenal would like to congratulate Glen, Tafari and Josh on signing professional terms, and look forward to their continued progression with the club.Copyright 2014 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source 7 Jul 2014