***epphd*** vacc question

CheriCO

Do you think there is possibly a benefit to getting multiple vaccines at once that is lost when parents do a delayed schedule and spread the vaccines out?  I'm wondering if the combined immune response to several vaccines might increase immunity to each.  I haven't looked too hard and not in about two years to see if there is any research on this and it's something that I have not heard discussed. 

epphd

Hi Cheri,

I don't know - in theory I don't see why a multivalent vaccine would elicit a more robust response to each individual antigen, but I suppose it's not impossible.  I suspect it's been evaluated in a way - if I have time today I can look at the immunogenicity of (for instance) the pentavalent DTP vax versus the component vaxes.   If the titers for each antigen are higher in the pentavax versus the trivalent or univalent vacces, then your theory may be right.

Our bodies are churning out multiple new antibodies every day, so it's hard to imagine that all of a sudden our B cells are acting differently because they see one antigen versus many, but I'm not an immunologist  

What HAS been studied is the immunogenicity of the standard vaccination schedule.  The delayed schedule has not been evaluated for efficacy in priming the immune response, and though it is likely just as effective, it does mean more visits and more shots and more opportunities to miss doses.

blue_elle

I have a follow-up - so there is no evidence currently to suggest that a delayed schedule is less effective at creating an immunity, correct? The concern would be that the child may miss a vaccine that should have been given within a specific time-frame. But if a parent were diligent about making sure that the vaccines are given at appropriate intervals there should be no long term difference? Also, if a woman is breastfeeding, does she not provide the child with her anti-bodies as long as she is breastfeeding?

Contrary to what some people on GP may now believe, I'm not anti-vax. I am all for vaccinations, but since immune system disorders are unfortunately common in my family, I want to do so in a cautious manner (not that I have kids, lol). I'm open to hearing everyone

epphd

I do not think it is possible to comprehensively study the effectiveness of delayed schedules since every "delayed schedule" is different from the other.

But just because "no study says it's less effective" doesn't mean it IS as effective.  It could be, it could not be.  It's a risk, IMO. 

Regarding BFing, not all types of antibodies are transmitted in breastmilk.  Whether you can confer immunity, temporarily, through breastfeeding varies based on your own titer for a given antibody and the antibody subtype.  Vaccines provide the child with the blueprint to make his/her own antibodies - breastfeeding passes on some of those antibodies, which circulate for a short period of time (as in days).  So it's really not a stand in for vaccinating. 

epphd

So Cheri, this does not exactly answer the question but it is interesting and I thought I would pass it along - an abstract from a recent Pediatrics study. Not only does it support the fact that on-schedule vaccination is in no way developmentally harmful - but it also reports that there appears to be a developmental advantage to timely vaccination.

On-time vaccine receipt in the first year does not adversely affect neuropsychological outcomes.

Smith MJ, Woods CR.

University of Louisville School of Medicine, Division of Pediatric Infectious Diseases, 571 S Floyd St, Suite 321, Louisville, KY 40202, USA. mjsmit22@louisville.edu

Abstract

OBJECTIVES: To determine whether children who received recommended vaccines on time during the first year of life had different neuropsychological outcomes at 7 to 10 years of age as compared with children with delayed receipt or nonreceipt of these vaccines.

METHODS: Publicly available data, including age at vaccination, from a previous VaccineSafety Datalink study of thimerosal exposure and 42 neuropsychological outcomes were analyzed. Vaccine receipt was defined as timely when each vaccine was received within 30 days of the recommended age. Associations between timeliness and each outcome were tested in univariate analyses. Multivariable regression models were constructed for further assessment of the impact of timeliness on neuropsychological outcomes after adjustment for potential confounders. Secondary analyses were performed on a subset of children with the highest and lowest vaccine exposures during the first 7 months of life.

RESULTS: Timely vaccination was associated with better performance on 12 outcomes in univariate testing and remained associated with better performance for 2 outcomes in multivariable analyses. No statistically significant differences favored delayed receipt. In secondary analyses, children with the greatest vaccine exposure during the first 7 months of life performed better than children with the least vaccine exposure on 15 outcomes in univariate testing; these differences did not persist in multivariable analyses. No statistically significant differences favored the less vaccinated children.

CONCLUSIONS: Timely vaccination during infancy has no adverse effect on neuropsychological outcomes 7 to 10 years later. These data may reassure parents who are concerned that children receive too many vaccines too soon.

(just starting to look into the efficacy question - I'll report back if I find anything)

 

CheriCO

That is interesting.  Thanks for researching   I think I'll do some browsing too.  There are sooo many articles out there, it's hard to sift through them.  I'm a science geek, too, so I appreciate the data/research driven discussion.