For children 2 years through
9 years, separate the first and
second dose by at least 28
days preferably, but 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.

For children 6 months through 9 years, using the same type of vaccine for 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.

Vaccines should be separated by at least 28 days preferably, but some experts suggest that 14 days* or longer is acceptable. If given 1-13 days apart, repeat the vaccine administered second at least 14 days* (preferably 28 days) from the invalid (second) dose. Administering both doses at the same visit is not recommended but if they are given at the same visit, neither vaccine needs to be repeated.

Vaccines can be administered on the same day or any interval (one or more days) between these vaccines is acceptable.

Vaccines can be administered at the same visit. If not administered at the same visit, vaccines should be separated by at least 28 days. If administered 1-27 days apart repeat the vaccine administered second at least 28 days* from the invalid (second)vaccine.

Vaccines can be administered on the same day or any interval (one or more days) between these
vaccines is acceptable.

For children 2 years through 9 years, using the same type of vaccine for first and second dose is preferred. If not feasible, separate 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.

For children 6 months
through 9 years, separate
first and second dose by at least 28 days preferably, but some experts suggest that 21 days* or more is acceptable.

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

Vaccines can be administered on the same day or any interval (one or more days) between these vaccines is acceptable.

Vaccines can be administered on the same day or any interval (one or more days) between these vaccines is acceptable.

Vaccines can be administered on the same day or any interval (one or more days) between these
vaccines is acceptable.

Vaccines can be administered on the same day or any interval (one or more days) between these vaccines is acceptable.

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.