Transmission electron micrograph of hepatitis B virions, CDC/Dr. Erskine Palmer.

Around 400 million people carrying hepatitis B virus could benefit from long-term treatment with lamivudine. But the drug's cost and a campaign by its manufacturer, GlaxoSmithKline, to "find and treat early," provoked complaints at a pre-congress symposium this afternoon.

The grim statistics are familiar to those who attended the symposium sponsored by GlaxoSmithKline (GSK): hepatitis B virus (HBV) kills between 1 and 2.5 million people a year and, overall, 15 to 25% of HBV carriers will die from chronic hepatitis, cirrhosis or hepatocellular carcinoma.

In some parts of the world, particularly south east Asia, carriers also face a high risk of an additional infection with the hepatitis A virus (HAV), leading to more rapid and severe disease.

According to Francis Andre, of GSK Belgium, the response should be a strategy already being piloted in Malaysia. Use rapid diagnostic kits to identify HBV carriers who have not yet developed any symptoms of disease, he said, and offer them a combination of treatment with either lamivudine or interferon, plus vaccination against HAV.

"We now have the total package of weapons to deal with hepatitis B," he noted. "The earlier you treat, probably the better the result will be."

On cost effectiveness, Andre said that a recent economic benefit study looked promising. But pharmaceutical companies would not survive if they gave into persistent demands to reduce costs, he insisted.

"You mustn't always ask us to come to the help of poor countries," he said. "There must be other mechanisms," he added, referring to private initiatives such as the Global Alliance for Vaccines and Immunization (Gavi).

Presenting the latest results of lamivudine therapy, Ching Lung Lai, of Queen Mary Hospital at the University of Hong Kong, stressed the drug's safety and effectiveness over at least 5 years for individuals with liver disease.

But other investigators, such as Betty Young, of the Pamela Youde Eastern Hospital in Hong Kong, remain concerned over the cost and long-term complications for treating all chronic carriers, including the appearance of drug-resistant mutants.

"I think this area has to be researched further," she told BioMedNet News.

According to Lai, however, viral mutants did not appear to worsen the outlook for patients, as they were "less competent and less aggressive" than the wild-type virus. Furthermore, new nucleoside analogue agents may soon be available to counteract the mutants, he proposed.

He warned, however, that the wild type virus becomes active again as soon as lamivudine therapy stops. In places where the cost of the drug means that continued therapy cannot be guaranteed, the treatment should be avoided altogether, Lai told a participant from Poland.

Furthermore, while lamivudine treatment appears effective at blocking viral replication, it does not eliminate the virus altogether, which reduces its appeal as a therapy for HBV carriers, according to John Tam of the Chinese University of Hong Kong.

"For the general public at the moment we really don't see a very big advantage from lamivudine treatment," Tam told BioMedNet News. "You don't see complete clearance," he said.

In addition, as a nucleoside analogue, lamividine poses the theoretical risks of causing DNA damage, creating risks if patients become pregnant while on treatment. The need to use long-term contraception then becomes a big issue, Tam warned.

Delegates agreed on the potential benefits of vaccinating chronic HBV carriers against the hepatitis A virus. For low-income countries, however, the lack of infrastructure presents a substantial obstacle to locating those in need.

"Introducing hep A vaccination for all chronic hep B carriers is a great idea," noted Jacob John, pediatrician and former president of the Indian Academy of Pediatrics, and advisor to the Indian Government. "But in countries like India you need to have the ability to test and find people who are hep B positive ... these issues are where we fall down," he said. "There's no good health system catching these people in India."