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.
Joint Committee on Vaccination and Immunisation
The JCVI has firmly endorsed the efficacy and safety of the MMR vaccine. Among many developments, in February, 1988, fifteen experts and officials met in the UK to discuss adverse events reported after the administration of the vaccines which contained the attenuated Urabe mumps virus strain. According to JCVI's minutes, the group "read a report of cases of mumps encephalitis which had been associated with MMR vaccine containing the Urabe strain of the mumps virus."