Vaccine-Preventable Diseases

Mumps

Mumps is an acute viral disease usually characterized by fever, swelling, and tenderness of one or more salivary glands. Prior to the widespread use of the mumps vaccine, mumps was a major cause of viral meningitis in Canada.

About one-third of exposed susceptible persons develop subclinical infections. Most infections in children < 2 years of age are subclinical. Complications are fairly frequent but permanent sequelae are rare. Deafness may occur in less than one to five cases per 100,000 population and is usually transient, but may be permanent occasionally. Mumps encephalitis has been reported to range as high as five per 1,000 cases, with a case-fatality rate of around 1.4%. Mumps infection may involve the testes in 15% to 25% of male cases occurring after puberty and the ovaries in 5% of female cases after puberty. Mumps infection during the first trimester of pregnancy may increase the rate of spontaneous abortion.

Through the 1940s and 1950s an average of 30,000 cases of clinical mumps were reported annually in Canada. The incidence has decreased remarkably since the introduction of vaccination in 1969 (Figure 7). From 1986 to 1995, an average of 509 cases were reported annually; incidence rates ranged from 1.2 to 3.5 per 100,000 population. More than 75% of cases occur among children aged 1 to 14 years with peak incidence in those 5 to 9 years of age.

1998 Update:  The reported incidence for mumps in 1998 was the lowest on record (Figure 3). One hundred and 10 cases were registered, a rate of 0.4/100,000. The highest age-specific incidence continued to occur in the five- to nine- year-old age group at 1.9/100,000 (38 cases), followed by the 10- to 14-year-old age group at 0.8/100,000 (17 cases) and the one- to four-year-old age group at 0.8/100,000 (12 cases). The male to female ratio was 3:2.

Figure 3) Crude incidence of mumps reported in Canada, 1924 to 1998. No national reporting between 1959 and 1985

Mumps Vaccine

Mumps virus vaccine is a live, attenuated virus vaccine and is available in combination with measles and rubella vaccines and in monovalent form. It is prepared from the Jeryl Lynn attenuated virus strain and is grown in chick embryo cell culture.

Efficacy and Immunogenicity

A single dose of the vaccine produces an antibody response in over 95% of susceptible individuals. Antibody levels, though lower than those that follow natural disease, persist for at least 20 years and provide continuing protection. In a Canadian study, however, a significant proportion of the vaccinees were negative for mumps antibodies 5 to 6 years after immunization. There are no data currently available correlating specific antibody titres with susceptibility to mumps, but outbreaks have been reported in highly vaccinated populations. A two-dose measles-mumps-rubella immunization schedule used in Finland resulted in higher mumps-specific antibody levels, higher seropositivity rate and slower decay of antibody levels.

Recommended Usage

Administration of live attenuated mumps vaccine in combination with measles and rubella vaccines (MMR) is recommended for all children >= 12 months of age. The combined vaccine should be used even in individuals who may have prior immunity to components of the vaccine, and it can be used to immunize susceptible adults against mumps.

Although mumps immunization after exposure may not prevent the disease, it is not harmful. Should the exposure not result in an infection, the vaccine should confer protection against future exposures.

Adverse Reactions

The most frequent reaction (approximately 5% of immunized children) is malaise and fever with or without rash lasting up to 3 days and occurring 7 to 12 days after MMR immunization. One in 3,000 children with fever may have associated febrile convulsions. Parotitis and mild skin rashes may occasionally occur after immunization. Very rarely, viral meningitis without sequelae has been reported.

Precautions and Contraindications

In common with other live vaccines, mumps vaccine should not be given to pregnant women or individuals whose immune mechanism is impaired as a result of disease, injury or treatment. An exception to this, however, is the recommendation that mumps vaccine, in the form of MMR, be given to HIV-infected children who do not have severe immunosuppression.

Mumps vaccine should not be administered less than 2 weeks before an immune globulin injection, or within 3 months after such an injection.

Convincing evidence supports the safety of routine administration of MMR vaccines to all children who have allergy to eggs. Fewer than 2 per 1,000 vaccinated eggallergic children have been found to be at risk for anaphylactic reaction to MMR (refer to the chapter on Measles Vaccine for further details of the Guide.

Since mumps vaccine contains trace amounts of neomycin and gelatin, people who have experienced anaphylactic reactions to previously administered neomycin or to a previous dose of mumps-containing vaccine, or who have a documented gelatin allergy should not receive mumps vaccine.

Selected References

Boulianne N, De Serres G, Ratnam S et al. Measles, mumps and rubella antibodies in children 5-6 years after immunization: effect of vaccine type and age at vaccination. Vaccine 1995; 13:1611-16. 

Buxton J, Craig C, Daly P et al. An outbreak of mumps among young adults in Vancouver, British Columbia, associated with "rave parties". Can J Public Health 1999;90:160-63. 

Caplan CE. Mumps in the era of vaccines. Can Med Assoc J 1999;160:865-66. 

Cheek JE, Baron R. Atlas H et al. Mumps outbreak in a highly vaccinated school population. Arch Pediatr Adolesc Med 1995;149:774-78.  

Davidkin I, Valle M, Julkunen I. Persistence of anti-mumps virus antibodies after a two-dose MMR vaccination at nine-year follow-up. Vaccine 1995;13:1617-22.

Duclos P, Ward BJ. Measles vaccines: a review of adverse events. Drug Safety 1998;19:435-54. 

Griffin MR, Ray WA, Mortimer EA et al. Risk of seizures after measles-mumps-rubella immunization. Pediatrics 1991;88:881-85.

James JM, Burks AW, Roberson PK et al. Safe administration of the measles vaccine to children allergic to eggs . N Engl J Med 1995;332:1262-66.

Miller E, Goldacre M, Pugh S et al. Risk of aseptic meningitis after measles, mumps and rubella vaccine in U.K. children. Lancet 1993;341:979-82.

Peltola H, Heinonen OP, Valle M et al. The elimination of indigenous measles, mumps and rubella from Finland by a 12 year two-dose vaccination program. N Engl J Med 1994;331:1397-1402.

West R, Roberts PM. Measles, mumps and rubella vaccine current safety issues. BioDrugs 1999;12(6):423-29.