My 2 year old daughter had the first vaccination for H1N1, but not yet the second.

[Anonymous]

Now I think I have H1N1 (102 degree fever, sore throat, sore muscles - and I had the regular flu vaccine at work).

Is she at risk from catching it from me, even with the first shot?

[Anonymous]

what is the percentage that is immune after one shot?

[Anonymous]

thanks, that is helpful. #1, 50/50 odds is better than 0%. #2, my daughter is a healthy big kid so maybe she is in the "good" 50, and #3, maybe I just have a bad cold. who knows?

we will get the 2nd shot as soon as we can.

[Anonymous]

penguinsix wrote:Varies by type manufacturer of the vaccine. Here is Sanfi Pasteur's study. Basically 76 percent of 3-9 year olds were ok 21 days after the first shot and 50 of the < 3 year olds had developed the immunity without the need for the second shot.

50-50....sorry...probably not much help.

The clinical trial in children evaluated immune responses to Sanofi Pasteur's Influenza A (H1N1) 2009 Monovalent Vaccine compared with placebo, based on rates of seroprotection and seroconversion. Two doses of vaccine were administered, the second dose 21 days after the first. Immunogenicity was measured at day 21, just prior to administration of the second dose, and will be measured again 21 days after the second dose at day 42. In both age groups, immune responses 21 days after one dose of the 15 mcg vaccine satisfied the criteria for seroconversion. The criteria for seroprotection were not met with only one 15 mcg dose of vaccine in either age group. In this clinical trial 76 percent of children 3 years through 9 years of age and 50 percent of children 6 months through 35 months of age had immune responses considered seroprotective following one 15 mcg dose of vaccine. An antibody titer of 1:40 or greater is generally considered a marker of seroprotection. A lower rise in antibody titers following vaccination may minimize the occurrence of disease and its consequences but is not considered seroprotective. Final data from these clinical trials, following a second dose of vaccine, will provide additional information to guide recommendations on the optimal dosage, number of doses and schedule.

Not the OP, but would you think that even if they weren't one of the lucky 50/50 ones, don't you think that the kid would have SOME protection? Maybe ease the blow of the flu versus being able to ward it off completely?

[Anonymous]

Anonymous wrote:

penguinsix wrote:Varies by type manufacturer of the vaccine. Here is Sanfi Pasteur's study. Basically 76 percent of 3-9 year olds were ok 21 days after the first shot and 50 of the < 3 year olds had developed the immunity without the need for the second shot.

50-50....sorry...probably not much help.

The clinical trial in children evaluated immune responses to Sanofi Pasteur's Influenza A (H1N1) 2009 Monovalent Vaccine compared with placebo, based on rates of seroprotection and seroconversion. Two doses of vaccine were administered, the second dose 21 days after the first. Immunogenicity was measured at day 21, just prior to administration of the second dose, and will be measured again 21 days after the second dose at day 42. In both age groups, immune responses 21 days after one dose of the 15 mcg vaccine satisfied the criteria for seroconversion. The criteria for seroprotection were not met with only one 15 mcg dose of vaccine in either age group. In this clinical trial 76 percent of children 3 years through 9 years of age and 50 percent of children 6 months through 35 months of age had immune responses considered seroprotective following one 15 mcg dose of vaccine. An antibody titer of 1:40 or greater is generally considered a marker of seroprotection. A lower rise in antibody titers following vaccination may minimize the occurrence of disease and its consequences but is not considered seroprotective. Final data from these clinical trials, following a second dose of vaccine, will provide additional information to guide recommendations on the optimal dosage, number of doses and schedule.

Not the OP, but would you think that even if they weren't one of the lucky 50/50 ones, don't you think that the kid would have SOME protection? Maybe ease the blow of the flu versus being able to ward it off completely?

Sorry, I hit submit before I clarified: I guess what I am asking is, say my 3 YO got one dose. Per what you cited, 76% of kids are TOTALLY protected -- doesn't it seem logical that the other 25% are at least SOMEWHAT protected?

[Anonymous]

I don't know if she will have full protection but she will definitely have some protection. The body starts making antibodies as soon as you get the vaccine.

The worst case is that even if she doesn't have full protection, she will have a head start fighting off the flu if she catches it.

Good luck!