Catalysis of the reaction: UDP-N-acetylgalactosamine + N-acetylneuraminyl-alpha-2,3-galactosyl-beta-oligosaccharide = UDP + N-acetylgalactosaminyl-N-acetylneuraminyl-alpha-2,3-galactosyl-beta-oligosaccharide.
Sda beta 1,4GalNAc transferase