A Fast and High Precision Influenza Vaccine Potency Assay

Vaccines are biological preparations that contain agents resembling disease causing microorganisms, and can improve immunity against a specific disease. They are typically prepared from inactivated or weakened forms of the microbe or its toxins, or surface proteins. Classical vaccines against the influenza virus are developed in embryonated hen eggs and may include whole virus, split virus or a purified subunit with every component other than hemagglutinin (HA) or neuraminidase (NA) removed.¹ The target molecule for the protective immune response triggered by vaccination is generally accepted to be the HA molecule; a glycoprotein found on the surface of the influenza virus. Measuring the vaccine potency or the biologically active components is critical to the determination of the vaccine’s effective dose. In addition, the stability of the vaccine has major impact on its usage for immunization programs worldwide. Although real-time stability studies under different storage conditions is preferable, thermal stability testing using potency assays with samples subjected to heat or environmental stress conditions can be used as predicators of vaccine stability over time.²