The present invention is related to a nucleic acid molecule capable of binding to human C5a, wherein the nucleic acid molecule comprises a central stretch of nucleotides, wherein the central stretch of nucleotides comprises a nucleotide sequence of 5′ AUGn1GGUGKUn2n3RGGGHUGUKGGGn4Gn5CGACGCA 3′ [SEQ ID NO: 61], wherein n1 is U or dU, n2 is G or dG, n3 is A or dA, n4 is U or dU, n5 is U or dU and G, A, U, C, H, K, and R are ribonucleotides, and dU, dG and dA are 2′-deoxyribonucleotides.