DTaP--one dose

[nicolebeth]

We're not inclined to get DTaP for our infant, DS2. But, I was wondering if there is any information out there whether the first dose (the one the CDC recommends getting at two months) is meant to confer any amount of immunity. We're going to the two-month appointment in a few weeks, and I can imagine being told that even that first dose will do "something". When looking into this five years ago with DS1, I thought I saw that it takes three doses to have any immunity--and, by that point, the baby is out of the danger range (and wasn't protected at all by the first three doses until all three were received). I looked at the pink book, and either the 2009 edits took that part out or I read this somewhere else.

TIA!

[Deborah]

Here is one study:
http://www.ncbi.nlm.nih.gov/pubmed/9080938

[nicolebeth]

Thank you, Deborah. I probably misunderstood, but it seemed to talk about immunity after three doses--one month afterwards and 14 months afterwards, comparing three different types of vaccines--a few DTaPs and a DTwP.

Again, we're not planning on him getting the vaccine. It's more that we want to weigh things properly. So, we can know (in deciding the vaccine is not worth it, too risky, etc.) that we may potentially be giving up a small amount of immunity (though, as I mentioned, I thought it took three shots for any immunity potentially to stick).

[Deborah]

Yes, it sounds as though they didn't even bother to check immunity after the first dose.

[MyTwoCherries]

Originally Posted by nicolebeth

We're not inclined to get DTaP for our infant, DS2. But, I was wondering if there is any information out there whether the first dose (the one the CDC recommends getting at two months) is meant to confer any amount of immunity. We're going to the two-month appointment in a few weeks, and I can imagine being told that even that first dose will do "something". When looking into this five years ago with DS1, I thought I saw that it takes three doses to have any immunity--and, by that point, the baby is out of the danger range (and wasn't protected at all by the first three doses until all three were received). I looked at the pink book, and either the 2009 edits took that part out or I read this somewhere else.

TIA!

I've been wondering about this as well. Our pediatrician told us one shot was about 50/50 and two pushed the numbers to 85% or so. I'm not sure where he got his information, I should have asked. I've been looking myself and haven't seen anything online.

DTaP is all that our little guy has had. We're in an area with pertussis and it worried me. We did one dose at 2 months and ds is now 4 months and we did another. I would have skipped the second but ugh. I just wasn't sure. It's so hard to know.

In my googling I did find an article w/ a link to a package insert but it still doesn't offer %'s after each individual vaccine, just %'s after the three doses. It shouldn't be hard info. to find. The fact that it is makes me leery about the importance of all three.

GL in your decision, if I see any additional info. I'll post here. I'm really curious also.

[nicolebeth]

Found something (that doesn't shed any light, other than to say that it is unknown whether one shot does anything):

There isn’t much data on the efficacy and protection from one or two doses of DTaP. Pertussis vaccine trials are difficult to do. Virtually everyone who has looked at this issue uses 3 doses as the benchmark. We know that with 3 doses efficacy is 80%-85%. We know that two doses are better than one, and one dose is better than none. But I don’t know of any data that would give us a feeling of how well one or two doses would protect against pertussis. (2/20/03)

http://www.cdc.gov/vaccines/vpd-vac/...htm#Additional

Then, the CDC has a link to a 2007 update that says people in outbreak areas should get the vaccines to their babies on an accelerated schedule.

My takeaway on this: one shot is not expected to do much to protect against pertussis.