Immunological status of Egyptian infants, children and adolescents againts mumps

ABSTRACT

In order to evaluate the immunological status against MUMPS, and hence the necessity for vaccination in Egypt, we measured the specific IgG antitibodies to mumps by ELISA in 200 subjects chosen non-randomly on purpose. Their ages ranged between 0-18 years, equally distributed between both sexes. Immunity was considered when the difference in absorbance value was > 0.2. The overall percentage of anti-mumps seroimmunity was found to be 71.5% in our subjects who were not vaccinated against mumps. No significant differeince was elicited between both sexes. All neonates [100%] in this study were immune. The age group 4 weeks -1 year had seroimimunity of 90% while the age group 1- 2 years showed the lowest seroimimunity being 23%. Then, seroimmunity increased vith the advance of age being 55% in the age group 2- G 6 years, 77.5% in the age. group 6 - 12 years and 90% in the 12 - 18 year old. The change of immunity with age was proved statistically to be highly significant. The mean IgG absorbance value [antibody concentration] in immune subjects was higher in the neonates [1.2 +/- 0.1] and adolescents [0.98 +/- 0.3] than in infants aging 1- 2 years [0.431 +/- 0.132] meaning that the latter age group had lower seroimmunity levels. The force of infection [power of virus transmission] was high below the age of 6 years being 0.280 between 1and 2 years of age and 0.240 in the age group 2 - 6 years. It was low in those aged 6 - 12 [0.176] and 12 - 18 years [0.118]. The mean age of maximum infection was 4.83 years. Mumps vaccination in Egypt is not mandatory in the presence of high seroimmnnity levels in adolescents. Nevertheless two dose schedule of mumps vaccine at 15 months and 12 years is expected to protect most persons from infection