Safety device for preventing needle stick injury with a needle of a medical injection device

A safety device for preventing needle stick injury with a needle extending from a distal tip of a medical injection device, comprising:

• a ring configured to be attached to the distal tip of the medical injection device;
• a protective shield movably coupled to the ring, the protective shield being configured to adopt successively a storage position wherein the protective shield covers the needle tip, an operative position wherein the protective shield uncovers the needle tip and a safety position wherein the protective shield covers the needle tip;
• a protective cap which is mounted on the ring in a storage position so as to cover at least the needle tip, and which can be separated from the ring prior to the use of the medical injection device;
• a retaining system comprising a first retaining portion arranged on the protective shield and a second retaining portion arranged on the protective cap, wherein the first and second retaining portions cooperate in the storage position to prevent the protective shield from moving to its operative position;
• wherein the safety device further comprises a releasing system
• for releasing the retaining system, the releasing system being configured to be activated by a manual inward pressure exerted on the protective cap.