There are vaccines to prevent infectious hepatitis and serum hepatitis, but none to prevent chronic hepatitis. Discuss why this is so
What will be an ideal response?
Chronic hepatitis is caused by the hepatitis C virus. Hepatitis C virus is an RNA virus, and the RNA polymerase which replicates the RNA genome lacks proofreading ability. As a consequence, new genetic variations with new antigenic structures are produced at high frequency. A vaccine against a single hepatitic C antigen would not provide protection from infection for all the variations, and a vaccine containing a large number of different antigens is not practical. Hepatitis A virus is not as variable, and hepatitis B virus is a DNA virus, DNA polymerases have proofreading functions.
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