The pneumococcal polysaccharide protein D-conjugate vaccine PCV-10 or SynflorixTM is a subunit toxoid-conjugated vaccine that contains ten capsular polysaccharide serotypes from the bacterium Streptococcus pneumoniae, eight of which are conjugated to a nonlipidated cell-surface lipoprotein (protein D) of non-typeable Haemophilus influenzae (NTHi) and two of which are conjugated to either tetanus or diphtheria toxoid (16). This evidence concerns the gene DHRS2 and diphtheria.