Quality Assessment of Some Brands of Tetanus Toxoids Marketed in Open Markets in South-Eastern Nigeria

Abstract

Aims: This study was designed to verify the immunogenicity (potency) and the safety of tetanus toxoid vaccines marketed in three large open drug markets in South-Eastern Nigeria. Methodology: Tests for Sterility, formaldehyde concentrations, specific toxicity, endotoxin, and immunogenicity (potency) were conducted on three different brands of tetanus toxoids (Brand α -from Ariaria Drug Market, Aba-Abia State; Brand β -from Ogbete Drug Market, Enugu State; and Brand γ -from Bridge-Head Drug Market, Onitsha-Anambra State).Results: All vaccine brands studied passed the sterility testing, but did not comply with the 2011 BP specifications on free formaldehyde concentration, which stipulates that the free formaldehyde concentration should not exceed 0.02%. The three vaccine brands did