New Hepatitis vaccine to be given trial

Press, 13 November 1985, Page 36

New Hepatitis vaccine to be given trial

PA Wellington Trials of a new geneticbased vaccine against hepatitis B, which promises to lower vaccination costs dramatically, will begin in the Whakatane area later this month. The senior investigator and leader of the immunisation team, Mr Sandy Milne, says it may be several years before the cost cuts reach the consumer. Existing vaccine is plasma-based, prepared from the infected blood of donors. Supplies of human blood are limited, and each batch must be tested over many months on chimpanzees.

New Zealand’s supplies come from the American company Merck, Sharp and Dohme, which is also developing the new vaccine. Among other variables, chimpanzees in the United States cost the company SUS6OOO ($10,300) each; the plasma vaccine costs SUSIOO ($172) a dose. The high costs have meant the vaccination is

least used where it is most needed - throughout Asia. That form of hepatitis is a serious jaundice common in the region and has been linked to liver cancer. In New Zealand, Mr Milne has pioneered a three-stage, low-dose vaccination which has significantly lowered the cost of the vaccination courses.

His work has enabled vaccination programmes to go ahead for all children in the Kawerau and eastern Bay of Plenty regions. Mr Milne’s studies found levels of infection and carriage in the eastern Bay of Plenty higher than “would normally be acceptable in any part of the Western world .

The new genetic-based product would further lower costs and eventually make the vaccine amenable even to Asian budgets. The vaccine is made by inserting the gene coding for the active protein principle into the genetic material of yeasts. The yeast “host” cells obey the gene’s instructions, and

make large quantities of the protein which can be har-

vested from the cell. Merck’s vaccine, known as Hepvax n, is already having clinical trials in Europe, the United States and South-East Asia, but other companies are reported to be close behind. The New Zealand trials are largely to evaluate possible different reactions from different ethnic groups, Mr Milne said. The evidence already showed that the end product was very similar to the plasma vaccine and equally effective.

Mr Milne said it was not known just how cheap the new vaccine would be, for obvious commercial reasons. Research costs were likely to be enormous, let alone the difficulties ’of retailing. “There’s no doubt it will provide the answer to the cost problem in a few years,” he said. “But I would say plasma vaccine will still be in use here in 10 years.”