Immunity occurs two weeks after the shot

[Anonymous]

Just FYI. A number of posts seem not to get this.

From the CDC website: "About 2 weeks after vaccination, antibodies that provide protection against 2009 H1N1 influenza virus infection will develop in the body."

http://www.cdc.gov/h1n1flu/vaccination/vaccine_keyfacts.htm

[Anonymous]

Thanks! I was looking for this info yesterday. Do you have any idea if kids under age 2 develop any useful antibodies before the 2nd shot?

[Anonymous]

I don't have a reference for this right now, but in the past week I heard someone from the CDC explain that they were seeing tests that showed (adults I think) immunity coming sooner -- more like 6 days than 14 days. I'll try to look that reference up.

[Anonymous]

Anonymous wrote:Thanks! I was looking for this info yesterday. Do you have any idea if kids under age 2 develop any useful antibodies before the 2nd shot?

The CDC site on this, which I can't find now, gave percentages. So something like 25% of kids develop immunity after the first shot and the rest after the second. I had read that with seasonal flu, there is some possibility that kids are actually more susceptible between shots but that some are also fully immunized after the first.

By the way, they also say about two weekas for seasonal flu shot immunity. I do no know if PP's info about possible faster immunity only applies to H1N1.

[Anonymous]

What about antibodies developing in the baby if I'm pregnant?

[Anonymous]

I read on the CDC website this morning that if you breastfeed you'll pass on your antibodies. To answer your exact question, you may find the answer here: http://www.cdc.gov/h1n1flu/vaccination/pregnant_qa.htm

[Anonymous]

This was the first reference I could find on the immunity factor for adults; I'm not sure who they are quoting, though.

http://www.nytimes.com/2009/10/10/health/10primer.html?_r=1

In general, immunity to H1N1 2009 kicks in about seven to eight days after the vaccine, slightly faster than the 10 to 14 days typical of seasonal flu vaccine. However, a child below the age of 10 will need two doses of the H1N1 vaccine, spaced about a month apart, and full immunity will not occur until about a week after the final dose.

[Anonymous]

Thanks so much 12:14 poster. The only thing I wonder is why the NYT writer got information saying we get immunity after 7-8 days when the CDC says it takes 14 days. I know there is no exact science. Thanks!

[Anonymous]

Anonymous wrote:Thanks so much 12:14 poster. The only thing I wonder is why the NYT writer got information saying we get immunity after 7-8 days when the CDC says it takes 14 days. I know there is no exact science. Thanks!

That page was updated last on Oct. 7th. I think the results of whatever study was done on efficacy came out just after that.

[Anonymous]

Good point. CDC website is dated 10/7. NYT article is dated 10/9. I like the NYT info better, so I'll go with that.
Hopefully the CDC will update its website.

[Anonymous]

it seems like the CDC likes to round up. http://www3.niaid.nih.gov/news/newsreleases/2009/H1N1TrialsResults.htm 8-10 days for a robust immune response sounds much better than 2 weeks to me.

[Anonymous]

Awesome! Thanks. There are some resourceful people here on DCUMs! Thank you so much as this makes a difference in deciding when and to where I take my pregnant self and children (after vaccination).

[Anonymous]

Completely anectodal but I think it takes less than 2 weeks in adults. The one adult in my house who got the H1N1 vaccine did not get sick and the rest of us did. This was about a week after the vaccine that everyone else had gotten sick.