A nasal spray to treat life-threatening allergic reactions has been given the green light by US regulators. Anaphylaxis, a severe and potentially fatal allergic reaction, requires immediate treatment with epinephrine, which is traditionally administered with an injection such as EpiPen. The newly approved product “neffy” offers a needle-free alternative by delivering epinephrine through a nasal spray. The spray is “the first epinephrine product for the treatment of anaphylaxis that is not administered by injection. Anaphylaxis is life-threatening and some people, particularly children, may del…