Assignment of opsonic values to pneumococcal reference serum 007sp and a second pneumococcal OPA calibration serum panel (Ewha QC sera panel B) for 11 serotypes. - Burton RL; Kim HW; Lee S; Kim H; Seok JH; Ku KY; Seo J; Kim SJ; Xie J; McGuinness D; Skinner JM; Choi SK; et al. (Vaccine, 2020)