Coronavirus vaccines in development
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More than 70 coronavirus vaccines are in development around the world with four drugmakers already running clinical trials
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How Sars-CoV-2 virus infects cells

Human cell
Virus genome
Spike protein
ACE2 receptor

Spike protein is potential candidate for vaccine

Infection: Virus relies on protein “spike” to bind to ACE2* receptor – entry point into human cell for virus to replicate

*Angiotensin-converting enzyme 2
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Viral vector vaccine

Spike protein gene is cut from Sars-CoV-2 genome

Adenovirus

Gene is inserted into DNA of adenovirus which acts as vector in vaccine

Vaccine induces spike protein antigen which triggers antibody immune response

Developed by CanSino Bio (China) and University of Oxford (UK)

Nucleic acid vaccine
 
Messenger RNA (mRNA) contains genetic recipe to produce spike protein antigen in human cells

mRNA   Human cell  Antigen  Antibodies 

Antigen stimulates antibodies
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DNA-plasmid vaccine      Developed by Moderna, Inc. and NIAID (U.S.)

Plasmids are circular DNA vectors

Plasmid

Plasmid is genetically engineered to contain spike protein gene

Developed by Inovio Pharmaceuticals (U.S.)

Vaccine is delivered via electroporation – electrical current increases antigen
delivery by nearly 1000-fold
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© GRAPHIC NEWS
Sources: Johns Hopkins University, Trial Site News, WHO


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