A PAINFUL injection of purified mouse brains could be a thing of the past for travellers if a new vaccine by Acambis gets the all-clear from regulators.

Acambis will announce today that it has had positive results from its Phase I/II trial for its vaccine for Japanese encephalitis. The new vaccine could be available as early as 2004 if further trials prove positive. Japanese Encephalitis, which is mainly found in Asia, is now the world's biggest viral killer. Nearly a third of the children who catch the disease die.

At present, the only vaccine available is made from mouse brains and has some painful side effects, including sore and inflamed arms. Japanese Encephalitis vaccination is currently a market worth around $200m. Chief executive John Brown said that the technology could also be used for vaccines against Dengue fever, West Nile encephalitis and Hepatitis C, which are all much bigger markets.

"This is a really pivotal point for the company," he said. "It gives us enormous confidence for all our vaccines based on this technology."

The ChimeriVax technology is based on the current live vaccine for yellow fever. It is named after the mythological monster, the Chimera, which was part lion, part serpent and part goat, because it is a combination of the yellow fever virus and the genes from the virus that the vaccine is targeting.

Mr Brown said that ChimeriVax appears to have no side effects. The Phase I/II trial tested the vaccine for safety, as well as giving some indication of whether it will produce an immune response in patients. "We have a lot of confidence in this," Mr Brown said.

11 February 2001: BioMedica to map canine genome