The virus used in the vaccine that helped eradicate smallpox is now working its magic on liver cancer. A genetically engineered version of the vaccinia virus has trebled the average survival time of people with a severe form of liver cancer, with only mild, flu-like side effects. Thirty people with hepatocellular carcinoma received three doses of the modified virus – code-named JX-594 – directly into their liver tumour over one month. Half the volunteers received a low dose of the virus, the other half a high dose. Members of the low and high-dose groups subsequently survived for, on average, 6.7...
