Vandermeulen C, Roelants M, Vermoere M, Roseeuw K, Goubau P, Hoppenbrouwers K. Department of Youth Health Care, Katholieke Universiteit Leuven, Kapucijnenvoer 35/1, 3000, Belgium.
Outbreak Of mumps In A Vaccinated Child Population: A Question Of Vaccine Failure? Vaccine. 2004 Jul 29;22(21-22):2713-6. 
In Belgium, children are immunized against measles-mumps-rubella (
MMR) in a two-dose schedule at the age of 15 months and 11 years. Despite these recommendations, epidemics of
mumps still occur. During an outbreak of
mumps in Bruges (Belgium), 105 cases were registered in seven schools (age group 3-12 years). Lower than optimal
vaccination coverage, inadequate
vaccination schedule and a combination of primary and/or
secondary vaccine failure are considered as possible reasons for the outbreak as described in the article.
The role of secondary vaccine failure is highlighted.
Primary vaccine failure is when the vaccinated individual either does not create any specific antibodies in response to the vaccine, or produces too little. Secondary vaccine failure is when the antibody levels decline over time.
This shows that artificial forms of immunity (vaccination) do not provide true immunity, and thus will need routine revaccinations. However, as this will never offer true immunity, the incidence of the disease will simply be pushed into older age groups. This is what is happening with disease such as mumps and measles.
Mumps is such a mild disease that it does not even require vaccination. According to The British Medical Association (BMA) and The Royal Pharmaceutical Society of Great Britain (RPSGB):- "Since mumps and its complications are very rarely serious there is little indication for the routine use of mumps vaccine": British National Formulary (BNF) 1985 and 1986.
