As schoolchildren are the most vulnerable, due to close proximity with each other, those children who have not taken the jabs could contract the infection easily.
Additional MMR shots will be provided by the Halton's School Health Nursing Team and is being planned at different locations for the New Year. Parents will also receive information regarding the availability of vaccinations.
Fiona Johnstone, director of health strategy at NHS Halton and St Helens, said: "We would urge people to ensure children and young adults have the two doses of this vaccine, which is the only way for them to protect themselves. Those who have not had the MMR vaccine, or who have only had one dose, can still be vulnerable to the virus."