Scientists about by for in of on up with the USA say they are getting closer to developing a vaccine that will provide life-long protection against any type about by for in of on up with influenza. This could be welcome news about by for in of on up with millions about by for in of on up with people around the world who go to the doctor every year to get a flu jab. Two different research teams have been testing new drugs about by for in of on up with animals and both have had promising results. Trials will soon begin about by for in of on up with humans to determine if the test vaccine has similar successes. Flu expert professor John Oxford told the BBC that: "This is a leap forward compared to anything done recently. They have good animal data, not just about by for in of on up with mice but about by for in of on up with ferrets and monkeys too." He added that: "It's a very good stepping stone." The flu virus kills about by for in of on up with to half a million people every year. The problem about by for in of on up with finding a vaccine is the ever-changing nature about by for in of on up with the flu virus. It is about by for in of on up with a constant state about by for in of on up with mutation. Doctors have to predict which strains about by for in of on up with the virus are likely to cause the most infections and then create an updated version about by for in of on up with the vaccine accordingly. For this reason, the success rate about by for in of on up with most flu vaccines is very low because much about by for in of on up with the process involves a lot about by for in of on up with guesswork. Scientists say that vaccines about by for in of on up with the U.S. reduced the risk about by for in of on up with catching flu about by for in of on up with just 23 per cent last year. The website Inverse.com said the research could, "point to how we can go about by for in of on up with making vaccines for other viruses that mutate rapidly, like HIV or the common cold".