2009 H1N1 Influenza Vaccine - Dose Spacing for Children 6 Months through 9 Years of Age

Separate the first and second dose by at least 28 days. Some experts suggest that 14 days* or longer is acceptable.

If given 1-13 days apart, repeat the second dose at least 14 days* (preferably 28 days) from the invalid (second) dose.

Using the same type of vaccine for the first and second dose is preferred. If not feasible, separate the first and second dose by at least 28 days preferably, but some experts suggest that at least 21 days* is acceptable.

If given 1-20 days apart, repeat the second dose at least 21 days* (preferably 28 days) from the invalid (second) dose.

Using the same type of vaccine for the first and second dose is preferred. If not feasible, separate the first and second dose by at least 28 days preferably, but some experts suggest that at least 21 days* or longer is acceptable.

If given 1-20 days apart, repeat the second dose at least 21 days* (preferably 28 days) from the invalid (second) dose.

Using the same type of vaccine for the first and second dose is preferred. If not feasible, separate the first and second dose by at least 28 days preferably, but some experts suggest that at least 21 days* or longer is acceptable.

If given 1-20 days apart, repeat the second dose at least 21 days* (preferably 28 days) from the invalid (second) dose.

¹Persons 10 and older require only one dose of 2009 H1N1 vaccine.
²2009 H1N1 LAIV and seasonal influenza LAIV are recommended for use in healthy people 2 years to 49 years of age who are not pregnant.
*These intervals apply ONLY to 2009 H1N1 vaccines and should NOT be applied to seasonal influenza vaccines. The Advisory Committee on Immunization Practices’ 4-day “grace period” (i.e. vaccine doses that are administered 4 or fewer days before the minimum interval can be counted as valid) should NOT be applied to 2009 H1N1 intervals.