Immune Response 
Given the extent of the current??pandemic, it's no surprise that researchers around the world are racing to find a SARS-COV-2 vaccine.??There are??four??main classes of vaccine candidates??that are being pursued, but one thing these approaches??have in common??is??the use of chromatography and??mass??spectrometry??methods??for their??characterization.???? In this article,??we look at examples from??each vaccine class where chromatographic separations have helped??in??the characterization of vaccines.

Virus??vaccines

Examples:??Measles vaccines,??polio vaccines??

Premise:??Virus vaccines take weakened, or attenuated,??forms of a virus to??create??a vaccine. These weakened viruses cannot cause disease to an individual,??but when presented to a person's immune system,??can still elicit an immune response. This gives the individual's immune system??memory of the pathogen??(e.g.,??immunity)??if it sees??the fully active form of the virus??at a later date.??

Methods??used:??A paper by????describes the use of??size??exclusion??chromatography (SEC)??to separate intact viral particles from disintegrated capsid proteins and uses??ion??exchange??chromatography (IEX)??to further purify the product.

Vaccine Development 

Viral??vector??vaccine

Examples:??Ebola vaccine

Premise:??A??virus is used as a vector and genetically engineered to produce proteins from another pathogen to build immunity. The vectors can either be replicating or??non??replicating.

Methods??used:??Anion??exchange??chromatography??(AEX), a type of IEX, was used by?? to determine full and empty AAV6 capsids.

??from the University of California reported the use of size exclusion chromatography for quantitative characterization of all single amino acid variants of a viral capsid-based drug delivery vehicle.??

Nucleic acid??vaccines

Examples:??While??no current human-licensed vaccines use??this method, over 20 research groups are working on vaccines in this category.????

Premise:??This technique uses DNA or RNA material from the pathogen that codes for a protein that causes an immune response.??

Methods??used:??In a review of purification techniques for DNA vaccines,??a team from the University of Canberra??covered a range of techniques from??affinity??chromatography??to??hydrophobic??interaction??chromatography??(HIC)??for purifying DNA plasmids for vaccines.??

Another team led by????characterized the??N-glycan??patterns of the Chikungunya virus glycoprotein,??similar??to??work??that??is??needed for the SARS-CoV-2 spike glycoprotein.??Release glycan kits??are now available to ensure the highest level of reproducibility and speed for further work.????

Vaccine Development 

Protein-based??vaccines

Examples:??Hepatitis B vaccine,??human papillomavirus (HPV) vaccine????

Premise:??These vaccines are typically based on viral protein subunits or virus-like particles (VLPs), and work by??direct??injection??of??proteins into the body. This allows the body to recognize??and??mount??an??immune response to the protein, rather than the whole virus.????

Methods??used:??The use of??size??exclusion??chromatography (SEC)??as a tool for protein-based vaccines is shown by??,??where they use BioSec-3 technology to determine the amount of the active form of novel??hemagglutinin (HA) that is used in??influenza vaccines.??

to discuss analytical methods for vaccines.