Principles of Vaccine Potency Assays

Abstract

Compared with biologics, vaccine potency assays represent a special challenge due to their unique compositions, multivalency, long life cycles and global distribution. Historically, vaccines were released using in vivo potency assays requiring immunization of dozens of animals. Modern vaccines use a variety of newer analytical tools including biochemical, cell-based and immunochemical methods to measure potency. The choice of analytics largely depends on the mechanism of action and ability to ensure lot-to-lot consistency. Live vaccines often require cell-based assays to ensure infectivity, whereas recombinant vaccine potency can be reliably monitored with immunoassays. Several case studies are presented to demonstrate the relationship between mechanism of action and potency assay. A high-level decision tree is presented to assist with assay selection.

A Revisit to the Research Updates of Drugs, Vaccines, and Bioinformatics Approaches in Combating COVID-19 Pandemic

“…Previously, different types of vaccines effectively protected animals against SARS-CoV, but sometimes, live virus vaccine led to lung damage and eosinophil infiltration in mouse (Tseng et al, 2012) and liver infections in ferrets (Weingartl et al, 2004). A new vaccine typically follows R&D, clinical trials, and approval from regulatory institutions, requiring 12-18 months to be available for marketing (Verch et al, 2018). Chen W. H. et al (2020) broadly divided COVID-19 vaccines in trial into three groups: whole virus vaccine, subunit vaccine, and nucleic acid vaccine.…”

Classification of Coronavirus (COVID-19) Treatments and Drugs Based on Mechanism of Action, Efficacy, and Safety

“…Because they are still in early stages of clinical trials or pre-human testing, these drugs will be at least one to two years before clinical use. (Verch et al 2018). As such, we will discuss generalized mechanisms of action rather than focus on the limited data on each individual drug.…”

“…It is easily manufactured and lowers the possibility of contamination. However, this vaccine will take at least one to two years for development before the vaccine is proven effective in multiple trials (Verch et al 2018). As a result, for immediate use, we are faced with the prospect of repurposing drugs (Sanders et al 2020).…”

“…Since the virus can be easily spread and is difficult to detect, vaccines are a promising prevention strategy. However, these vaccines are 12-18 months away from widespread use (Verch et al 2018). Thus, there is an immediate need for both prevention strategies and curative therapies.…”

Biological technique used as alternative method in the vaccine potency assays: in - house sandwich ELISA for Rabbit haemorrhagic disease virus

“…Initially, empirical vaccines (derived from killed pathogenic organism) were used, but the development of biological sciences (e.g., biochemistry, cell culture technology, immunology, molecular biology, molecular genetics) led to a new generation of vaccines, safer and immunogenic, that are based on scientific design approaches (TOMAR & al, 2005 [1]; PLOTKIN, 2014 [3]). In the same way, the vaccine potency assays evolved from the expensive and laborious in vivo assays (e.g., immunization of dozens of animals) to the inexpensive and simple modern analytical tools (e.g., immunochemical methods) (VERCH & al, 2018 [4]). The in vitro vaccine potency assays seem to be the best approach because they avoid the use of experimental animals and the antigen determination or activity determination by using relevant immunoassays become the most extended methods of in vitro potency assays in veterinary vaccinology (LUCKEN, 1999 [5]; HENDRIKSEN, 2009 [6]; BROWN & STOKES, 2012 [7]; ROMBERG & al, 2012 [8]).…”