Children under 10 need two shots, given at least 21 days apart. About two weeks after the second shot, they should gain immunity. So according to the CDC recommendations your 9-year-old would need the second shot as well. But as always, I would say ask your doctor. Blanket recommendations are not as good as speaking to your physician.

From a CBC article:
The U.S. National Institutes of Allergy and Infectious Diseases (NIAID) released clinical trial data Monday showing that children under 10 didn’t respond well enough to one dose of adjuvant-free H1N1 vaccine to consider them protected against the virus. Based on those data, the U.S. is sticking to its earlier recommendation that children under 10 get two doses of H1N1 vaccine, given at least 21 days apart.

Is the WHO’s statement based on the canadian and european versions which are adjuvanted? That’s what I understood–the US versions are less efficacious at a single dose because of this difference in manufacture. A real bummer to be sure for those of us who only manage to scare up the first puzzle piece. Good luck to everyone seeking the shots!

The statement that 1 dose is likely sufficient for children to develop immunity comes from the new data (via GlaxoSmithKline, producer of the Canadian adjuvanted vaccine) that is showing that 100% of children they’ve monitored have shown a positive immune response from a single dose. The children monitored were in the 6-36 month range and had th adjuvanted vaccine, which is recommended for children due to it’s greater effectiveness. My daughter got that shot and is 21 months, so I find this reassuring. I assume that the older a child is the stronger their immune system response – but that’s my assumption and I have no reference for it.

http://www.cbc.ca/cp/health/091030/x103002A.html

In any case, I believe the current recommendation by those actually administering the shots is still to get 2 for children under 10.

On a side note, there’s a useful H1N1 vaccination group here if someone hasn’t mentioned it already on this blog (I’m a bit behind):
http://www.facebook.com/groups.php?ref=sb#/group.php?gid=161444432417

However, I am in the same position as the other mothers who have posted, my children will need a second dose of H1N1 in 2 weeks, and will likely not get it.

I was unaware that the first shot merely primed the system, I assumed there would be partial immunity in 10-14 days. If the first shot primes, but doesn’t give immunity, why is the World Health Organization now saying one dose is sufficient? It sounds to me like 1 dose isn’t enough, except in situations where there is a pandemic.

You shouldn’t give parents the impression that their childen are immune when they are not, so that you can help save vaccine for more people. We should be given accurate information. Tell us our children aren’t protected, but don’t blatantly lie. This whole situation is dispicable!

I’m concerned that my kids may not get the second dose, due to shortages as well. They aren’t doing a good job distributing the vaccine in our area, and people have begun to act crazy about it! My mother is an RN, and she volunteered all day yesterday to administer shots and mist. She said that people were upset and angry and there were shouting matches. At the vaccine clinic! One woman demanded that my mom give her a written guarantee that the vaccine wouldn’t make her sick. My mother told her that she assumed the woman had already decided to get the vaccine, or she wouldn’t have come out and stood in line, so maybe she should just go sit down and think it over. So, the woman did.

People think the vaccine will hurt them in some way, but then they go stand in line for hours to get the vaccine, and antagonize the volunteers when they get there. The whole situation is crazy!