Evaluation of Mumps Vaccine Effectiveness in Vaccinated Children in Thi-Qar Province, Iraq

Background: Outbreaks of mumps continue to take place in a number of regions across the globe, with Iraq being one of the countries that occasionally experiences epidemics. Objectives: This study aimed to evaluate whether the Mumps vaccination is efficacious in children who have been vaccinated. Methodology: The case-control study included 176 children (117 vaccinated and 59 unvaccinated), aged less than thirteen years. The ELISA technique was used to detect the presence of mumps virus IgG in them sera. Results: The seroprevalence of mumps IgG in the vaccinated group was positive in 110 (94.0%) of 117 children. While in the unvaccinated group it was positive in 45 (76.3%) of the 59 children. This study found a significant difference between both groups (X2 = 11.754, p value < 0.001) using the chi-square test. According to sex, there was a significant difference between males and females in the vaccinated groups (p value = 0.037) by using the t-test, but there was no significant difference by sex using the chi-square (X2 = 0.542, p value < 0.462) in the same group. Our study also did not find any significant difference according to the number of vaccine doses (p value = 0.246), but there was a significant difference in results according to age group (p value = 0.049). Conclusions: The current study concluded that the mumps vaccine is potently effective for Iraqi-vaccinated children in Thi-Qar province. The outbreaks in other places in Iraq may be attributed to weak vaccine coverage in areas suffering from battles and the displacement of citizens.