Timing of Kids' Flu Shots: Tricky, Vital

Some children may need as many as four flu vaccinations this season, to get protection from the H1N1 and seasonal bugs.

On "The Early Show" Tuesday, CBS News Medical Correspondent Dr. Jennifer Ashton went through various possibilities for kids of various ages.

This year, we have two different flu vaccinations - H1N1 and the seasonal flu. For young children, how many total doses could we be talking about?

Let's start with the H1N1 vaccine, for kids under 10 years, they will need two doses. If your child is under 9 years of age and has never gotten their flu shot, they will need two doses of the seasonal vaccine as well. That means your child could have up to 4 doses. However, most children - if they have gotten their seasonal flu shot before - will either need two or three doses, depending on their age.

Can the seasonal flu vaccine and the H1N1 2009 vaccine be taken at the same time?

The two vaccines come in two different versions: the shot or the spray. If your child gets the injectable version, you can get the two shots on the same day - but they should be given on different arms. If they only need 1 of each, then, they're done.
If they are under 10 years old, they can get their second H1N1 shot one month after.

Unfortunately, unlike the injectable version, the child cannot take the spray version of both on the same day. Because the seasonal and H1N1 flu spray vaccines are made from a live, but weakened virus, they should not be taken at the same time. The spray vaccine inoculations should be separated by four weeks.

Can you mix the two versions: shot and the spray?

Yes, the nasal spray vaccine can be administered at the same visit as the shot. So, you can do either combination of the seasonal flu shot and H1N1 spray ... or the H1N1 shot and the seasonal flu spray. Again, if your child is younger than 10 years, they will need to get their second dosing three weeks later.