Rubella viruses. Coloured transmission electron micrograph of rubella viruses, the causative agent of German measles; and belonging to the togavirus group of viruses . They consist of a lipoprotein coat or capsid and a core containing single- stranded genetic RNA material. The rubella virus is transmitted in air-borne droplets. The disease it causes, german measles, most commonly affects children as a mild rash. German measles is a risk to unborn babies in the first four months of pregnancy. Rubella vaccine is now routinely given to young babies, which provides immunity. Magnification: x48,000 at 6x4.5cm size