Sero-response to measles-mumps-rubella vaccine campaign in Saudi Arabia

OBJECTIVE: To evaluate the measles-mumps-rubella vaccine campaign targeting primary school children in the Kingdom of Saudi Arabia during the months of January and February 2000.

METHODS: Pre and post measles-mumps-rubella vaccine blood samples were collected from 54 children from the first grade and 96 children from the 6th grade. Antibodies against measles, mumps and rubella were assayed using enzyme immunoassay and a backup test of plaque neutralization test. This assay was carried out at the Reference Center, Koch Institute, Berlin, Germany.

RESULTS: When the backup test results were added, 96%-98% of children had protection level against measles before the campaign. It is interesting to notice that pre-vaccination measles mean titer and positivity rate with enzyme linked immunoassay in the first grade were significantly lower than the 6th grade. One hundred percent and 96.8% were positive for rubella antibody before the campaign, in the first and 6th grades. Seventy-seven percent and 67% were positive for mumps before the campaign, in the first and 6th grade. After the measles-mumps-rubella vaccine campaign, protection rate reached 100% for the 3 antigens with a statistically significant boosting effect and increase in geometric mean of the titre.

CONCLUSION: Measles-mumps-rubella vaccine campaign was effective in increasing protective levels and boosting antibodies against the 3 targeted diseases which can prevent epidemics in the primary schools.