Thoughts, comments on dT vaccine as primary series

[japonica]

Just wanted to get your perspective on this...including the very knowledgeable abstainers...

Background: neither of my children have been vaccinated to date. My main issues are 1) safety of injected aluminum (Shaw, Tomljenovic etc.) and 2) I just don't think that many of the vaccines on the schedule are necessary, okay I'll qualify that, not necessary for MY family from MY perspective.

We moved from somewhere where the ground was frozen solid for about six months of the year to a place that is frost-free year round. The kids are playing in the dirt year round and as they get older and are off on excursions etc., they are under the care of teachers who perhaps are not as diligent about wound care as I would be, and that concerns me.

Yes, I know all about how statistically, it's more likely some senior out gardening who would get tetanus, not a healthy, robust kid. I also know how incredibly rare it is. I'm familiar with that.

Nevertheless, we have been in discussion with our family GP about the merit in doing the dT vaccine. Reasoning...it's the one option that doesn't come with a load of other antigens I don't want (like the infant combos containing pertussis, polio, hep B and the like) and it also has the least amount of aluminum of any other option.

If it provides a smidge of diphtheria protection, that'd be okay too, considering the case in Queensland back in 2011 where an unvaccinated woman came down with clinical diphtheria from her vaccinated friend who had just returned from Asia and apparently infected her with the bacteria. The woman died. Yes, also incredibly rare. Yet, many of my daughter's classmates holiday regularly in Indonesia, which still has about 800 reported cases a year (according to the WHO).

Okay, so looking at the Australian government's Immunisation Handbook, it states that the dT can be used as a primary course (three doses).

The product information for ADT Booster states that this vaccine is indicated for a booster dose only in children aged ≥5 years and adults who have previously received at least 3 doses of diphtheria and tetanus vaccines. NHMRC recommends that, where a dT vaccine is required for any person ≥8 years of age, ADT Booster can be used, including for primary immunisation against diphtheria and tetanus.

http://www.immunise.health.gov.au/internet/immunise/publishing.nsf/Content/Handbook-tetanus

But then when you look up the actual product insert for the ADT booster, it states:

ADT™ Booster is not intended for primary immunisation against diphtheria and tetanus.

http://www.csl.com.au/docs/778/399/ADT%20Booster%20PI%20-%20approved%20Jan2010.pdf

Interesting. So, do you think it's worth an email to both the government and manufacturer to find out what's the deal? 

I did consider that it was perhaps because the antigen levels, as a booster, are so low...2 IU for diphtheria and 20 IU for tetanus (compared to 30 IU and 40 IU in the infant combos). But then I decided to check and see if there was any data on using a similar product as a primary course back in Canada and found this:

The schedule for routine immunization of persons ≥ 7 years of age is a three-dose series of adolescent/adult formulation of diphtheria toxoid-containing vaccine, as noted in the Recommended Immunization Schedules chapter. The second dose is given 2 months after the first, with a third dose 6 to 12 months later to complete the course.

http://www.phac-aspc.gc.ca/publicat/cig-gci/p04-dip-eng.php

And the data for Td Adsorbed is:

The immunogenicity of Td ADSORBED administered as a series of three doses for primary immunization was evaluated in 17 subjects ages 6 to 56 years in a study conducted in Canada. The first two doses were administered two months apart, followed by a third dose six to eight months after the second dose. Serum tetanus antitoxin levels were measured by an in vivo neutralizing assay, and serum diphtheria antitoxin levels were measured by an in vitro neutralizing assay. All 17 subjects had serum tetanus and diphtheria antitoxin levels pre-vaccination and 7 days post-vaccination <0.01 IU/mL, consistent with no previous immunization. Four weeks following the second dose of Td ADSORBED, all 17 subjects had a serum tetanus antitoxin level >0.1 IU/mL and a serum diphtheria antitoxin level ≥0.01 IU/mL. Four weeks following the third dose, all 17 subjects had a serum diphtheria antitoxin level >0.1 IU/mL.

https://www.vaccineshoppecanada.com/document.cfm?file=td_adsorbed_e.pdf

According to the Canadian Immunization Guide, antitoxin titres of >0.1 IU/mL are considered protective.

The Td Adsorbed and the ADT Booster seem to contain similar amounts of toxoids. The Canadian one is in Lf vs. IU. It also has more aluminum and 2-phenoxyethanol, residual formaldehyde (ugh, but probably in the ADT Booster as well).

Anyway, does anyone have any info on how Lf equates to IU and second is there good data in the US on Td being used as a primary course? 

Like I said, we're discussing options with the GP and I want to go into this with as much info as possible. We're not interested in any of the infant combos. They will not be getting any other vaccines until puberty, at that point we'll re-evaluate the risk and benefits of others. Again, nothing set in stone there either.

And yes, having not given either child any vaccines to date, I am aware, as stated, how rare either clinical diphtheria or clinical tetanus is. However, I cannot be with them all the time to ensure adequate wound care nor can I be 100% sure that their classmates don't bring home unwanted souvenirs from their last trip to Indonesia.

Thanks.

Edited by japonica - 9/4/12 at 7:54pm

[ma2two]

5 Lf tetanus = 20 IU tetanus

http://www.phac-aspc.gc.ca/publicat/ccdr-rmtc/05vol31/asc-dcc-1/index-eng.php (see table 1 where next to tetanus, it says 10 Lf = 40 IU.

So the Australian diphtheria/tetanus vaccine, containing 20 IU tetanus, has the same amount of tetanus as the U.S. DT, containing 5 Lf tetanus.

http://www.csl.com.au/docs/778/399/ADT%20Booster%20PI%20-%20approved%20Jan2010.pdf

http://www.fda.gov/downloads/BiologicsBloodVaccines/Vaccines/ApprovedProducts/UCM101500.pdf

The U.S. DT vaccine package insert says, "Diphtheria and Tetanus Toxoids and Acellular Pertussis Vaccine (DTaP) – Tripedia®, or DTP is recommended for primary immunization of infants and persons up to 7 years of age. However, in instances where the pertussis vaccine component is contraindicated, or where the physician decides that pertussis vaccine is not to be administered, DT should be used."

Meaning, they want you to vaccinate for pertussis if you can, but you don't want to, so that doesn't apply to you.

The Australian diphtheria/tetanus does have less diphtheria than the U.S. DT.

Diphtheria conversion: multiply Lf by 1.2 to get IU.

6.7 Lf diphtheria = 8.04 IU diphtheria

Austrlian vaccine only has 2 IU. But maybe they make up for that by almost 3 times more aluminum than the U.S. DT? Aluminum is used as an adjuvant, to increase the immune response to the antigen.

[japonica]

Thanks for the info 

Interesting...yeah, that is quite a difference in the aluminum...0.17mg to 0.5mg (which was looking better than the 1.5mg in the infant combo ones here). That is perhaps the reasoning behind the higher amount (supposedly increase the immune response). Still, it's not great.

The difference in the diphtheria content I suppose is the nature of the vaccines...DT vs. dT. Australia had a CDT (basically a pediatric DT similar to the States) but they discontinued it back in 2005 or 2006.

Hmm... I did find this product in the States, Decavac, which seems closer to what's available here:

http://www.fda.gov/downloads/BiologicsBloodVaccines/Vaccines/ApprovedProducts/UCM246215.pdf

It has 5 Lf tetanus and 2 Lf diphtheria, 0.28 mg aluminum.

It states that it did provide protective levels of antibody at those levels:

The effectiveness of primary immunization with tetanus toxoid and diphtheria toxoid used in DECAVAC vaccine was determined on the basis of an immunogenicity study, with a comparison to a serological correlate of protection (0.01 antitoxin units/mL) established by the Panel on Review of Bacterial Vaccines & Toxoids. (7) A clinical study to evaluate the serological responses was performed in 58 individuals 6-58 years of age. Of these, 46 persons had no evidence of prior immunity to tetanus toxin and 47 persons had no evidence of prior immunity to diphtheria toxin. The results indicated protective levels of antibody were achieved in greater than 90% of the study population after primary immunization with both components. (4) 

So, that I guess answers my question about comparable US products and any studies indicating that adult boosters can be used for a pediatric primary series...the fact that the Aussie ones contain a heck of a lot of aluminum by comparison though is not great.

 

Edited to add: I just noticed that Tenivac is actually replacing Decavac (even though both are still listed on the FDA site). They seem to be similar in composition with the antigens, although Tenivac has slightly more aluminum (1.5 mg aluminum phosphate, equivalent to 0.33 mg aluminum).

Edited by japonica - 9/5/12 at 12:30am

[nukuspot]

I know of a ND here in the US who does 3 DTs as a primary series for her kids (under the age of 7) for the tetanus, same as you.  Whether or not they are different brands, etc, I don't know, I would assume so.  But I always thought if it as an option for us if we ever choose to (I worry about wound care at school, same as you mentioned, but my DD just started preschool.  I will reassess when she starts K in a few years.)