Durable influenza protection Vaccines are indispensable for the control and prevention of influenza, but there are several challenges to efficacy. Some individuals respond poorly to vaccination, and virus variation makes targeting optimal antigens difficult. Broadly neutralizing antibodies are one solution, but they have their own pitfalls, including limited cross-reactivity to both influenza A and B strains and the need for repeated injections. Now, Laursen et al. have developed multidomain antibodies with breadth and potency. Administered intranasally to mice with an adeno-associated virus vector, the antibodies provided durable and continuous protection from a panoply of influenza strains. Science , this issue p. 598