A vial adaptor for connecting a medicine vial or any type of vessel or device that has a head section similar to that of the head section of a medicine vial to another component of a drug transfer system, said vial adaptor comprising: a) a bottom part adapted to be attached to the head section of a medicine vial or any type of vessel or device that has a head section similar to that of the head section of a medicine vial; b) a top part comprising: (i) a disk shaped central piece and a plurality of wings adapted for facilitating securement of said top part of said vial adaptor to said bottom part of said vial adaptor, said wings attached to the circumference of said disk shaped central piece and projecting distally away from it; (ii) a longitudinal extension projecting proximally from said disk shaped central piece, said longitudinal extension adapted to be coupled to said another component of a drug transfer system (iii) a membrane that seals the proximal end of said longitudinal extension; (iv) a spike element which protrudes distally from the center of said disk shaped central piece; (v) an air channel and a liquid channel both of which are internally formed within said longitudinal extension and said spike element; c) a first locking mechanism; and d) a second locking mechanism; wherein, said first locking mechanism is adapted to lock said top part of said vial adaptor to said bottom part of said vial adaptor such that the tip of said spike element cannot contact a stopper in said head section when said head section of a medicine vial or any type of vessel or device that has a head section similar to that of the head section of a medicine vial is being attached to said bottom part of said vial adaptor and to release said top part of said vial adaptor from said bottom part of said vial adaptor after said bottom part of said vial adaptor has been attached to said head section of a medicine vial or any type of vessel or device that has a head section similar to that of the head section of a medicine vial; and said second locking mechanism is adapted to allow said spike element to penetrate said stopper in said head section of a medicine vial or any type of vessel or device that has a head section similar to that of the head section of a medicine vial and to irremovably lock said top part of said vial adaptor to said bottom part of said vial adaptor after said bottom part of said vial adaptor has been attached to said head section of a medicine vial or any type of vessel or device that has a head section similar to that of the head section of a medicine vial; the vial adaptor characterized in that said air channel and said liquid channel are adapted to allow fluid communication through said vial adaptor from openings in the tip of said spike element to said membrane that seals the proximal end of said longitudinal extension; thereby providing a closed transfer device that allows transfer of air and liquid between the interior of said medicine vial or any type of vessel or device that has a head section similar to that of the head section of a medicine vial and said other component of a drug transfer system. a) a bottom part adapted to be attached to the head section of a medicine vial or any type of vessel or device that has a head section similar to that of the head section of a medicine vial; b) a top part comprising: (i) a disk shaped central piece and a plurality of wings adapted for facilitating securement of said top part of said vial adaptor to said bottom part of said vial adaptor, said wings attached to the circumference of said disk shaped central piece and projecting distally away from it; (ii) a longitudinal extension projecting proximally from said disk shaped central piece, said longitudinal extension adapted to be coupled to said another component of a drug transfer system (iii) a membrane that seals the proximal end of said longitudinal extension; (iv) a spike element which protrudes distally from the center of said disk shaped central piece; (v) an air channel and a liquid channel both of which are internally formed within said longitudinal extension and said spike element; (i) a disk shaped central piece and a plurality of wings adapted for facilitating securement of said top part of said vial adaptor to said bottom part of said vial adaptor, said wings attached to the circumference of said disk shaped central piece and projecting distally away from it; (ii) a longitudinal extension projecting proximally from said disk shaped central piece, said longitudinal extension adapted to be coupled to said another component of a drug transfer system (iii) a membrane that seals the proximal end of said longitudinal extension; (iv) a spike element which protrudes distally from the center of said disk shaped central piece; (v) an air channel and a liquid channel both of which are internally formed within said longitudinal extension and said spike element; c) a first locking mechanism; and d) a second locking mechanism;