1. A method of treating a subject infected by a virus which acquires its envelope from a membrane associated with the intracellular membrane comprising: a) administering to the subject an antiviral vaccine comprising an antigenic fragment of the virus; and b) administering to the subject an effective amount of an agent which inhibits morphogenesis of the virus and a pharmaceutically acceptable carrier. 2. The method according to claim 1, wherein the virus is characterized by acquiring its envelope from a membrane associated with the ER of a virus-infected cell. 3. The method according to claim 1, wherein the agent is a glucosidase inhibitor and the effective amount is an amount effective to inhibit the activity of a glucosidase. 4. The method according the claim 1, wherein the subject is human. 5. The method according to claim 1, wherein the virus is hepatitis B virus. 6. The method according to claim 1, wherein the virus is hepatitis C virus. 7. The method according to claim 5, wherein the antigenic fragment is HBV HBsAg protein or a fragment thereof. 8. The method according to claim 1, wherein the agent is selected from the group consisting of N-alkyl derivative of a 1,5-dideoxy-1,5imino-D-glucit- ol. 9. The method of claim 8, wherein the derivative is N-nonyl-1,5-dideoxy-1,5-imino-D-glucitol.

File Number: 08-1C