Keeping one step ahead of the Flu

The development of vaccines for seasonal and pandemic influenza is discussed. Influenza viruses are defined by two spike-like antigenic proteins which include hemagglutinin (HA) and neuraminidase (NA) - on the surface of the virus particle. The spikes protrude from a lipoprotein envelope that encloses a single-stranded RNA genome comprising eight separate ribonucleoprotein segments. The vaccine is administered using a particle-mediated epidermal delivery device known as PowderJet. With the device, DNA is precipitated onto microscopic gold particles that are then propelled by pressurized helium gas at high speed into immunologically active antigen presenting cells of the epidermis.