Vaccinations could one day come in the form of a tasty morsel of fish, rather than via an injection, researchers have claimed. Singaporean researchers have created zebrafish that produce vaccines in their muscles. They say the technology could also be used in more commonly eaten fish, such as salmon. But they say the fish would have to be eaten raw because cooking would destroy the vaccine. Hmmm, vaccines Sushi Style. Researchers from the National University of Singapore have genetically modified zebrafish so that they produce hepatitis B vaccine. The next stage will be to test the sashimi vaccine on animals which can be infected with hepatitis B to see if eating the fish has a protective effect. The researchers say previous studies in this area to make vaccines in plants or animals in this way have been unsuccessful because they do not produce enough protein. But they suggest the zebrafish could produce large amounts of protein. They estimate every kilo of fish muscle could produce 27 grammes of vaccine.