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The hepatitis B virus vaccine consists of a major surface antigen called HBsAg, which is a lipid‐bound protein that self‐assembles into 22 nm spherical noninfectious virus‐like particles (VLPs). The HBsAg VLP particles are expressed in yeast and have been well‐characterized biochemically and biophysically employing various analytical techniques. In fact, a CZE method has been developed for monitoring process purification of the hepatitis B vaccine. Another CE‐based method, imaged capillary IEF (icIEF) has been used extensively in the field of protein‐based drug development as a tool for product identification, stability monitoring, and characterization. Here we describe the development of the icIEF method using the iCE280 instrument from ProteinSimple for measuring the pI and monitoring the profiles of HBsAg VLP particles. This method was applied to characterize the stability of the HBsAg VLP particles in three different formulation buffers. The results show that HBsAg VLP particles have a pI of 2.7 and it is one of most acidic particles that we have measured by icIEF. In addition to icIEF, we have also employed a CZE method to measure the electrophoretic mobility of HBsAg VLP particles and compared the results with icIEF and dynamic light scattering methods, showing consistent correlation among the three methods in terms of HBsAg VLP particles aggregation.

Dengue is known to cause morbidity and mortality worldwide and currently there is neither available specific therapeutics to treat nor a vaccine to prevent this disease. Although efforts are being made, development of a vaccine against this disease remains challenging. Hawaii Biotech Inc developed a recombinant subunit envelope protein-based vaccine against all four serotypes produced in Drosophila S2 cells which were transferred over to Merck in 2010. Each subunit of the four dengue serotypes contains the N-terminal 80% of the amino acids comprising the envelope protein (DEN-80E). A Phase 1 study using only monovalent DEN1-80E was done by Hawaii Biotech Inc and most recently, a Phase 1 clinical trial of the tetravalent DEN-80E formulation (V180) was conducted. Here, we report the development of a dose assay for the tetravalent dengue vaccine-containing subunit protein of DEN1-80E, DEN2-80E, DEN3-80E, and DEN4-80E using various separation methods such as HPLC and CE. Based on the results of the comparison, the CZE separation was chosen as the most suitable method to perform the dose assay for the tetravalent dengue vaccine.

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