Developing a live vaccine is a tricky balancing act.But it can become more of a sure thing if the vaccine developer puts a thumb on the scales.That’s one way to describe the approach taken by Peking University researchers.They decided to tweak the influenza A virus genetically so that it would not only remain fully capable of activating the immune system,but would also Developing a live vaccine is a tricky balancing act.But it can become more of a sure thing if the vaccine developer puts a thumb on the scales. That’s one way to describe the approach taken by Peking University researchers. They decided to tweak the influenza A virus genetically so that it would not not only fully fully capable of activating the immune system, but would also