A new “Holy Grail” flu vaccine which gives lifelong protection against all strains of the virus could be available within five years. Scientists from Britain and Europe are getting ready to start large-scale trials of a universal vaccine after early tests on humans proved successful. If all goes to plan, the new injection would stop the need for annual flu jabs and could save thousands of lives every year. It could also be effective against highly dangerous forms of the disease, such as Spanish flu, even if they mutate, preventing global pandemics like the one which killed 100 million people...