How is hepatitis A different from hepatitis B? Would a vaccine against A protect against B?

Hepatitis A and B have different routed of transmission.

A vaccine against A doesn't protect against B.

Explanation:

Type A hepatitis is spreaded by the intake of contaminated water or food, and hepatitis B is transmitted by blood via sex, perinatal or contaminated needles

Unlike hepatitis b, hepatitis A does not cause chronic liver disease

The hepatitis B vaccine only works for this type of hepatitis because this vaccine is made up of parts of the hepatitis B virus. The viruses that cause hepatitis A and B are different, therefore different vaccines are needed.