The second stage of the Health Ministry's special operation on children's vaccination began in Lviv Region on 18 February.
Around 50,000 children are planned to be vaccinated in the coming three weeks, subject to parents' consent.
In some schools, vaccinations will be made by mobile brigade, in other areas children will have to visit local hospitals.
"For today, the Health Ministry has provided Ukraine with the sufficient number of quality vaccines. And now we are helping the regions to protect the children who missed vaccination in the past. We are calling on parents not to waste time because measles can have serious and even mortal consequences," Deputy Health Minister Olha Stefanishyna said.
Lviv Region is the leader in terms of registered measles cases and one of the antileaders by measles vaccination.
There were almost 12,000 measles cases in the region last year and already 3,446 cases this year.
The measles rate in Ukraine has got close to the pre-vaccination period of 1968.