Rubulavirus
If not vaccinated against mumps, susceptible individuals catch the disease by breathing around an infected person who has coughed or sneezed, releasing their contaminated saliva. Those who have had mumps are usually immune to future infections of the disease. Children have the highest risk of catching mumps, and it is rare for an adult to contract mumps. The incubation period for mumps can range from a couple weeks to a month, while the illness period is a few weeks. The swelling of the salivary glands is caused when the virus travels from the respiratory tract to the salivary glands and multiplies within the glands, causing the glands to swell.
MMR vaccine controversy
The MMR scare caused a low percentage of mumps vaccination (less than 30%), which resulted in outbreaks in Japan. There were up to 2002 measles-caused deaths in Japan while there were none in the UK, but the extra deaths were attributed to Japan's application of the vaccine at a later age. A spokesman for the Ministry of Health said that the discontinuation had no effect in measles, but also mentioning that there were more deaths by measles while MMR was being used. In 1994 the government dropped the vaccination requirement for measles and rubella due to the 1993 MMR scare. Japan is nowadays the only developed country with large measles epidemics. It has been called a "measles exporter" by the US Centers for Disease Control and Prevention. As another consequence of the scare, in 2003, 7 million schoolchildren had not been vaccinated against rubella.