Q. My child is under 10 and has received his first dose of H1N1 vaccine. Will there be enough vaccine to get the second dose 28 days later? The first dose was a nasal spray, what if nasal spray is unavailable later?
A. US CDC recommends that the two doses of H1N1 vaccine for children 9 years of age and younger be separated by 4 weeks. There is no maximum number of days between doses.
Ideally the same type of vaccine – nasal spray or injection – should be used for both doses. If different types of vaccine are used for the first and second doses, however, there is no need to revaccinate a child.