The Role of Bioassays in Vaccine Development

Bioassays have an essential role to play in vaccine development and there are now calls being made to develop standards which will allow both manufacturers and regulators to better assess bioassays.

USP Standards

US Pharmacopeial (USP) Convention introduced a number of new chapters to the National Formulary this year as part of its efforts to provide guidance for manufacturers and regulators using bioassays.

Revisions were made to the General Chapter Design and Analysis of Biological Assays, to facilitate the"rapid progress in computational analysis, assay design tools, and statistical understanding", Tina S. Morris, PhD, vice president, biologics and biotechnology at USP, writing for BioPharm International explained.

The standards centre around combining data from multiple bioassays, using equivalence testing and evaluating curve similarity.

It is the view of USP that such changes need to be made to ensure that bioassays fulfil their potential as new avenues of treatments for diseases progress.

Roger Williams, M.D., USP’s chief executive officer, said: "As the very promising field of biologic therapies develops it is crucial that bioassays be current with the state of this rapidly evolving science."

Bioassays in Vaccine Development

The development of a TB vaccine with a higher efficacy than the current Bacille Calmette-Guérin (BCG) vaccine is one area in which bioassays could play a major role.

Aeras Global TB Vaccine Foundation was recently awarded $362,102 (£233,000)   from the United States Food and Drug Administration for the development of biomarkers for the development of a TB vaccine.

BCG was developed created in the 1920s and there is still little understand as to how it produces an immunological response.

The creation of a biomarker would significantly enhance research into the vaccines by allowing research to take place across a range of institutions and streamline the regulatory review of the clinical data.

"Functional and biologically relevant immunological responses that correlate with vaccine efficacy remain elusive for tuberculosis so we are fortunate to be working with leaders in bioassay research to tackle this essential component of TB vaccine development," Thomas G. Evans, MD, Chief Scientific Officer of the Aeras Global TB Vaccine Foundation.

The Jenner Institute, University of Oxford; the South African Tuberculosis Vaccine Initiative of the University of Cape Town; Saint Louis University; and Albert Einstein College of Medicine are all collaborating on the project, which will look to produce four  mycobacterial growth inhibition assays.

The aim is for these assays to then be used to "identify T-cell immune and antibody responses that may be associated with ex vivo growth inhibition and potentially with protective vaccines."

Advanced Bioassays

Among the increasingly advanced bioassays being designed is a bioassay chip technology developed by researchers at Stanford University, which is 1,000 times more sensitive than the devices currently in clinical use.

The chip is capable of scanning any body fluid for cancer related proteins, allowing it to identify cancer biomarkers at earlier stages.

Using nano-magnets, the chip has shown it is capable of detecting cancerous-tumours in mice when proteins are not yet developed enough to be detected by conventional methods, research published in Nature Medicine shows.

The chip was said to be capable for use with any body fluid and capable of identifying 64 different proteins in a single analysis, meaning it is potentially much faster than existing assays.

Charles Drescher, a professor of obstetrics and gynecology at the University of Washington in Seattle, commented: "The idea that you could essentially, on a single assay platform, measure a broad diversity of biomolecules that are at such a wide range of concentrations with such sensitivity is really, truly remarkable."