Chimp test for oral hepatitis B vaccine
Oral vaccination for hepatitis B has moved one step closer to human trials. Two years ago, virologists made a vaccine of viruses genetically engineered to carry parts of the hepatitis B virus (SN: 7/18/87, p.39) and showed it could immunize hamsters against the disease. Now, scientists at the same laboratory have successfully immunized chimpanzees, with their human-like immune systems, using a similar vaccine in a gelatin capsule.
An oral hepatitis B vaccine could cost less, hurt less and store better than the three-shot regimen of current vaccines for the disease. The virus, spread through blood and sexual contact, can cause liver diseases. It currently infects about 300 million people worldwide.
With their colleagues, Michael D. Lubeck of Wyeth-Ayerst Research in Philadelphia and Robert H. Purcell at the National Institute of Allergy and Infectious Diseases in Bethesda, Md., attached the major surface antigen of the hepatitis B virus to adenoviruses, which normally infect human lungs but can also grow in the gut. The team fed the still-viable viruses to three chimps.
The type 4 and 7 adenoviruses used in the study can cause acute respiratory disease if inhaled. But growing in the gut, they induce immunity rather than illness. …