OPKA – Opsonophagocytic Killing Assay.

An assay used to measure the functional capacity of vaccine-candidate raised antibodies. The assay aids in selecting promising vaccines by demonstrating whether the vaccine induced antibodies drive efficient complement deposition and subsequent opsonophagocytic killing.

OPKA makes it possible to reproducibly estimate the phagocytic titre of sera from vaccinated and un-vaccinated individuals.

The assay is used commonly to assess pneumococcal vaccine immunogenicity.