Antitoxin component of a type II toxin-antitoxin (TA) system (PubMed:27672196). Neutralizes the effect of cognate toxin VapC2 but not non-cognate toxin VapC2 (PubMed:27672196). Probably forms a complex with cognate toxin VapC2. The C-terminal 33 residues are required to neutralize cognate toxin VapC2 (PubMed:27672196). Belongs to the VapB family.