A needle assembly for use with a drug delivery device comprises a cap releasably secured to the drug delivery device and a blocking member. The blocking member comprises a disinfectant swab and a user graspable portion. The blocking member is configured to be physically moved with respect to the needle assembly by a user. The needle assembly is configured such that in an initial position, the blocking member blocks the cap from being removed from the drug delivery device and movement of the blocking member from the initial position causes the disinfectant swab to contact a septum of a cartridge retained within the drug delivery device.
