The vaccination course consists of two doses. The recommended interval between doses is 21 days.
The day that the first dose of vaccine is given is day 0.
If the interval between doses is longer than 21 days, the second dose should be given as soon as possible. The course does not need to be restarted.
If the second dose is given more than 4 days before the minimum interval (i.e., before 17 days), this is not considered a valid dose. A third dose should be given at least 21 days after the second (invalid) dose.
**Note this is a different interval compared to that for children aged 6 months to 4 years **