Although round, the measles virus is classed as a cubic form. There is an outer envelope studded with small spiky projections (pink). The coiled rope formation inside is actually the capsid (red), taking this shape instead of the box-like shell seen in some viruses. The nucleic acids which carry the genetic code of the virus are wound in a spiral inside the cord-like capsid. This is a plastic model designed from electron micrographs. The measles (rubeola or morbilli) is an infectious viral disease spread by sneezed or coughed airborn droplets. Measles mainly affects children, but can occur at any age, the adult form being more severe. One attack usually gives lifelong immunity. Flu-like symptons develop accompanied by fever and a rash. Complications include chest infections, diarrhea and vomiting. Vaccination against measles provides immunity.