2.2.1 Primary vaccination
In countries where transmission is high and continuous, children should be vaccinated starting at 9 months of age. Any child not vaccinated before age 1 year should be vaccinated as soon as possible.
In countries where transmission is low or nonexistent, primary vaccination is given later, at 12 to 15 months of age.
In certain high-risk situations where children are heavily exposed before 9 months of age, it is recommended that they be given an early dose at or after age 6 months, and then the EPI recommended dose at age 9 months, with at least 4 weeks between the two doses.
These situations include:
– measles epidemics;
– population concentrations (refugee/IDP camps, precarious urban zones);
– paediatric inpatient units;
– children born to HIV-positive mothers (increased risk of severe measles and little protection conferred by maternal antibodies);
– malnourished children (increased risk of complications).
2.2.2 Second dose
The second dose can be:
– administered during follow-up campaigns to children ages 6 months to 5 years (sometimes over age 5 years, depending on the epidemiological situation);
– added to the national immunization programme schedule: a second dose at age 15 or 18 months, for example.