The hepatitis virus has already run through alphabets A to E. A recent study could well slot it up to J.

Tests conducted on a frozen blood specimen 30 years old led to the discovelry of 3 previously unknown hepatitis viruses. Tentatively called GB-A,' GB-B and GB-C, the viruses belcwig to the Flavivirus family which includes 2 known viruses - hepatitis C an d yellow fever.

Scientists at Abbott Laboratories, Chicago, where the new viruses were discovered, are unsure of how far the new viruses affect humans.