Am I increasing immunity or renewing it with a second dose?

[papaya-luv]

Anyone have any helpful info on effectiveness and immunity in general relating to spacing doses differently than recommended? I guess I'm confused about whether the immunity to the diseases are less effective with fewer, more spaced out doses, or if the only difference is in how long the immunity will actually last.

I was not vaxing until age one, then gave DD2 the Pentacel shot at 1 year and 2 months, (DTaP, Polio, Hib). I then decided to hold off and learn more about selective and delayed vaxing before giving her any other doses. Closing in on one year later, she is super strong and healthy and aside from a couple minor colds she's never been sick, but now that she's 2 and has a stronger system, I am thinking about a second dose of the Pentacel and eventually MMR. She might start going to daycare now too.

Here's where I'm stuck: The recommended second dose for the Pentacel was after 2 months, and it's been almost 12 months, so if I give her a second dose of the same vaccine now will it be "increasing" her immunity or just "renewing" it? Does this depend on the disease? Did I drop the ball by not following the recommended spacing and now we would be pretty much starting fresh? Any info or links would be tremendous help. Thanks!

[papaya-luv]

Found this on the official CDC Catch-up Immunization Schedule:

"A vaccine series does not need to be restarted, regardless of the time that has elapsed between doses."

[wombatclay]

From the Sears Vaccine Book (and personal experience)... some vaccinations do have specific timings.  For instance, allergy shots may need to be started over if the sequence is interrupted and some vaccinations cannot be given before/after a certain age.  But in general the "common" vaccinations aren't that specific, and you shouldn't have to repeat shots you've already had.  In fact, an older child may require fewer shots to achieve the same level of coverage.

If you're considering child care programs, check your state and local laws regarding vaccination waivers.  Some states (or individual care providers) are more stringent about vaccination while others are more open.  I know here there are private schools/programs that set their own vaccination requirements that are different from those held by the public schools.  If you're looking to limit vaccinations then it would be a good idea to find out what the minimums are for the programs you're interested in.

In terms of protection, in general if a specific vaccination is designed to be given more than once the level of protection from the disease in question /should/ increase with each additional shot.  However, the amount of increased protection varies, and it's the first shot that usually gives the largest increase (so, say, the first shot reduces your risk of getting the illness by 50%, while the second shot reduces it by another 25%, and the third shot reduces it by only an additional 10%).  And booster shots are a different matter... a booster isn't really designed to stand on its own but rather to maintain or restore a level of protection that was previously established through vaccination or exposure.