A semisynthetic meningococcal C conjugate vaccine of the formula wherein m and n are integers ranging from 1 to 10; R 1 and R 2 are same or different and independently represent H, C 1-6 alkyl, acetyl; R 4 represents H or C 1-6 alkyl; R 5 represents H, C 1-6 alkyl, aryl; CP represents a carrier protein, which is preferably selected from Tetanus toxoid, diphtheria toxoid or cross reacting moiety 197; L 1 is a bond, -O-, -S-, -NRg-, -C(=O)-, -NR 8 C(=O)-, -NR 8 C(=O)O-, -C(=O)NR 8 -, -OC(=O)NR 8 -, -SC(=O)-, -C(=O)S-, -OC(=O)-, -C(=O)O-, -NR 8 C(=S)-, -C(=S)NR 8 -, trans -Cr 9 =CR 9, cis -CR 9 =CR 9, -C=C-, -OC(R 9)2-, -C(R 9) 2 O-, -NR 8 C 2 -, -C 2 NR 8 -, -SC 2 -, -C 2 S-, -S(=O) 2 O-, -OS(=O) 2 -, -S(=O) 2 NR 8 -, -NR 8 S(=O) 2 -, or an optionally substituted C 1-20 hydrocarbon chain, optionally wherein one or more carbon units of the hydrocarbon chain is replaced with -O-, - S-, -NRg-, -C(=O)-, NR 8 C(=O)-, -NR 8 C(=O)O-, -C(=O)NR 8 -, -OC(=O)NR 8 -, -SC(=O)-, -C(=O)S- -OC(=O)-, -C(=O)O-, -NR 8 C(=S)-, -C(=S)NR 8 -, trans -CR 9 =CR 9 -, cis -CR 9 =CR 9 -, -C=C-, -S(=O) 2 O-, -OS(=O) 2 -, -S(=O) 2 NR 8 -, or -NR 8 S(=O) 2, wherein R 8 is hydrogen, optionally substituted C 1-6 alkyl, or a nitrogen protecting group, or Rg is joined with the adjacent carbon atom to form an optionally substituted heterocyclic ring, and wherein each occurrence of Rg is independently selected from the group consisting of hydrogen, halogen, optionally substituted C 1-10 alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted carbocyclyl, optionally substituted heterocyclyl, optionally substituted aryl, and optionally substituted heteroaryl, or Rg is joined with the adjacent carbon or nitrogen or oxygen atom to form an optionally substituted carbocyclic or heterocyclic ring, or two Rg groups are joined to form an optionally substituted carbocyclic or optionally substituted heterocyclic ring; L 2 is a moiety derived from a crosslinking reagent capable of crosslinking the carrier and L 1, wherein L 2 is selected from and R 7 is independently hydrogen, optionally substituted C 1-6 alkyl, optionally substituted acyl, or a nitrogen protecting group, with a proviso that when m is 1 to 2, then n is not 1 to 5. wherein m and n are integers ranging from 1 to 10; R 1 and R 2 are same or different and independently represent H, C 1-6 alkyl, acetyl; R 4 represents H or C 1-6 alkyl; R 5 represents H, C 1-6 alkyl, aryl; CP represents a carrier protein, which is preferably selected from Tetanus toxoid, diphtheria toxoid or cross reacting moiety 197; L 1 is a bond, -O-, -S-, -NRg-, -C(=O)-, -NR 8 C(=O)-, -NR 8 C(=O)O-, -C(=O)NR 8 -, -OC(=O)NR 8 -, -SC(=O)-, -C(=O)S-, -OC(=O)-, -C(=O)O-, -NR 8 C(=S)-, -C(=S)NR 8 -, trans -Cr 9 =CR 9, cis -CR 9 =CR 9, -C=C-, -OC(R 9)2-, -C(R 9) 2 O-, -NR 8 C 2 -, -C 2 NR 8 -, -SC 2 -, -C 2 S-, -S(=O) 2 O-, -OS(=O) 2 -, -S(=O) 2 NR 8 -, -NR 8 S(=O) 2 -, or an optionally substituted C 1-20 hydrocarbon chain, optionally wherein one or more carbon units of the hydrocarbon chain is replaced with -O-, - S-, -NRg-, -C(=O)-, NR 8 C(=O)-, -NR 8 C(=O)O-, -C(=O)NR 8 -, -OC(=O)NR 8 -, -SC(=O)-, -C(=O)S- -OC(=O)-, -C(=O)O-, -NR 8 C(=S)-, -C(=S)NR 8 -, trans -CR 9 =CR 9 -, cis -CR 9 =CR 9 -, -C=C-, -S(=O) 2 O-, -OS(=O) 2 -, -S(=O) 2 NR 8 -, or -NR 8 S(=O) 2, wherein R 8 is hydrogen, optionally substituted C 1-6 alkyl, or a nitrogen protecting group, or Rg is joined with the adjacent carbon atom to form an optionally substituted heterocyclic ring, and wherein each occurrence of Rg is independently selected from the group consisting of hydrogen, halogen, optionally substituted C 1-10 alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted carbocyclyl, optionally substituted heterocyclyl, optionally substituted aryl, and optionally substituted heteroaryl, or Rg is joined with the adjacent carbon or nitrogen or oxygen atom to form an optionally substituted carbocyclic or heterocyclic ring, or two Rg groups are joined to form an optionally substituted carbocyclic or optionally substituted heterocyclic ring; L 2 is a moiety derived from a crosslinking reagent capable of crosslinking the carrier and L 1, wherein L 2 is selected from and R 7 is independently hydrogen, optionally substituted C 1-6 alkyl, optionally substituted acyl, or a nitrogen protecting group, with a proviso that when m is 1 to 2, then n is not 1 to 5.