Results: No significant differences in cognitive and intelligence tests results were observed between
children vaccinated with MMR and those not vaccinated up to the end of the 2nd year of life. Children
vaccinated with MMR had significantly higher Mental BSID-II Index (MDI) in the 36th month than
those vaccinated with single measles vaccine (103.8 ± 10.3 vs. 97.2 ± 11.2, p = 0.004). Neither results of
Raven test nor WISC-R were significantly different between groups of children vaccinated with MMR
and with single measles vaccine. After standardization to child’s gender, maternal education, family economical
status, maternal IQ, birth order and passive smoking all developmental tests were statistically
insignificant.