The essentials
- Usual timing
- First dose at 12 months. Second dose usually given as MMRV at ages 4–6.
- How to get it
- Ask a primary care provider or public health unit about local appointments and funding.
Protects against measles, mumps and rubella. Measles can cause pneumonia or brain inflammation; mumps can affect hearing and other organs. Rubella is especially dangerous during pregnancy.
School status
All three diseases are included in Ontario’s school requirements, unless a valid exemption applies.
Side effects & precautions
Soreness, redness or swelling where the needle went in can occur. Fever or a mild rash may appear 6–23 days after vaccination. Side-effect guidance
Rare serious reactions include a fever-related seizure or severe allergy. MMR is a live vaccine: discuss pregnancy, a weakened immune system, medicines that weaken immunity, and recent blood products or immune globulin (an antibody treatment) before vaccination.
Call 911 for trouble breathing or swelling of the tongue or throat. Not sure whether a reaction is expected? Contact a healthcare provider or call 811 for advice. Seek care promptly if symptoms are worrying or getting worse.
Useful to know
Travel, exposure or an outbreak
A provider may advise an earlier dose or an earlier second dose. A dose before the first birthday does not replace the two routine doses given from 12 months onward. If measles is suspected, call ahead before entering a clinic. Early-dose guidance
MMR and autism
Large studies have found no link between MMR vaccination and autism. If you notice a change in your child’s development, arrange a healthcare assessment. Evidence about MMR and autism
Ingredients & more detail
Check the exact product
Ask the clinic for the product name. Its official Canadian product information (product monograph) lists ingredients, packaging, side effects and precautions. This page is a short overview, not a complete safety list.
Find a product in Health Canada’s Drug Product Database
Priorix — Canadian product monograph (PDF). This is one product example; confirm which product the clinic uses.
Less common reactions, such as swollen glands, are described in the product information.
Your next step
Bring the immunization record and a list of questions to the visit. Ask which doses count, what comes next and how to report new doses to public health.
Sources and references (7)
- Ontario — routine immunization schedule
- Canadian Immunization Guide — measles vaccines
- Ontario — vaccines for children at school
- Canadian Immunization Guide — vaccine safety and monitoring
- Health Canada — Drug Product Database and product monographs
- Priorix — Canadian product monograph (PDF)
- Canadian Immunization Guide — precautions and contraindications
Program details can change. How this guide is reviewed