An injection port assembly 100 for coupling to and uncoupling from a first fluid pathway of a first connector and for receiving and passing a fluid into the first fluid pathway from a device provided with a second connector, said injection port assembly comprising: a) a body 106 having a first end 106a provided with a first mating structure adapted to mate with the first connector, and a second end 106b provided with an opening and a second mating structure adapted to removably couple to the second connector; b) a hollow spike 104 coupled to and at least partially surrounded by said body 106, said hollow spike 104 having a penetrating tip 109, said first mating structure and said hollow spike 104 being in fluid communication with each other; c) a resilient first barrier108 extending over said spike 104 and having a tip portion 108c about said tip of said spike 104; and d) a resilient second barrier 112 provided over and contacting said tip portion 108c of said first barrier; characterized in that: said resilient second barrier 112 has a lower frustrum 112b and an upper frustrum 112d of smaller diameter defining a shoulder 112a, the shoulder 112a having a larger diameter than the opening of the second end 106b of the body 106, said upper frustrum 112d having a continuous swabbable surface 112c, wherein when the second connector is coupled to said second mating structure, said second connector forces said second resilient barrier 112 and said tip portion 108c of said first resilient barrier 108 over said spike 104 such that said second connector and said first connector are in fluid communication with each other through said hollow spike 104 and said first mating structure, and e) a centering member 110 for axially centering said first barrier 108 and said resilient second barrier 112 relative to said spike 104, said centering member 110 has a first tapered opening 110a dimensioned to accommodate said lower frustrum 112b, and the lower frustrum 112b has a diameter larger than said first tapered opening 110a providing a mechanical interference to frictionally hold said second barrier 112 in the centering member 110. a) a body 106 having a first end 106a provided with a first mating structure adapted to mate with the first connector, and a second end 106b provided with an opening and a second mating structure adapted to removably couple to the second connector; b) a hollow spike 104 coupled to and at least partially surrounded by said body 106, said hollow spike 104 having a penetrating tip 109, said first mating structure and said hollow spike 104 being in fluid communication with each other; c) a resilient first barrier108 extending over said spike 104 and having a tip portion 108c about said tip of said spike 104; and d) a resilient second barrier 112 provided over and contacting said tip portion 108c of said first barrier; characterized in that: said resilient second barrier 112 has a lower frustrum 112b and an upper frustrum 112d of smaller diameter defining a shoulder 112a, the shoulder 112a having a larger diameter than the opening of the second end 106b of the body 106, said upper frustrum 112d having a continuous swabbable surface 112c, wherein when the second connector is coupled to said second mating structure, said second connector forces said second resilient barrier 112 and said tip portion 108c of said first resilient barrier 108 over said spike 104 such that said second connector and said first connector are in fluid communication with each other through said hollow spike 104 and said first mating structure, and said resilient second barrier 112 has a lower frustrum 112b and an upper frustrum 112d of smaller diameter defining a shoulder 112a, the shoulder 112a having a larger diameter than the opening of the second end 106b of the body 106, said upper frustrum 112d having a continuous swabbable surface 112c, wherein when the second connector is coupled to said second mating structure, said second connector forces said second resilient barrier 112 and said tip portion 108c of said first resilient barrier 108 over said spike 104 such that said second connector and said first connector are in fluid communication with each other through said hollow spike 104 and said first mating structure, and e) a centering member 110 for axially centering said first barrier 108 and said resilient second barrier 112 relative to said spike 104, said centering member 110 has a first tapered opening 110a dimensioned to accommodate said lower frustrum 112b, and the lower frustrum 112b has a diameter larger than said first tapered opening 110a providing a mechanical interference to frictionally hold said second barrier 112 in the centering member 110.