This enables the protein shell of the virus to be analysed at the atomic level - something a billion times smaller than a pinhead.

BBC: Synchrotron yields 'safer' vaccine

In this research the scientists created a synthetic viral shell, but lacking its pathogenic RNA interior - the genetic material the virus uses to replicate itself.

BBC: Synchrotron yields 'safer' vaccine

However, dogs primarily catch the virus while in close quarters with other dogs that are coughing and sneezing, says Steven Shell, head of Merck's U.S. companion animal group.

WSJ: A New Breed of Flu Shot to Avoid Getting Sick as a Dog