- Hi Friend of Deer,
UPS picked up the envelope and brochures about noon today, so you
should have them some time on Wednesday.
There is something that I should give you a "heads up" about. Earlier
this summer at Princeton, it was discovered that some of the deer
treated with SpayVac in 2004, last year, gave birth to fawns - quite
unexpectedly. However, the deer that had been treated in 2003 had NOT
become pregnant in either 2004 or 2005.
This had us quite perplexed at first, but the cause soon became
evident: the vaccine that had failed to produce the desired result
had been given a heat treatment to 85 degrees Celsius (185 F) rather
than the usual 75 degrees Celsius (167 F). At Princeton and a couple
of other trial sites where the 85 degree SpayVac had been used, we
found reduced efficacy.
IVT had used the higher heat treatments to try to achieve a higher
sterility standard with SpayVac, as they had done this with other
vaccines without a loss of efficacy. However, with the PZP in
SpayVac, the story turned out differently.
I understand that some articles about this have appeared in some NJ
newspapers, although I have not yet seen any of them. Some writers,
I'm sure, will try to portray this as proof that SpayVac doesn't work
(and that contraceptive vaccines for wildlife management cannot work).
There is nothing basically wrong with SpayVac. It has performed very
well and continues to perform very well - except for the batches that
were treated at 85 degrees C. All future vaccine to be used in trials
will be SpayVac "classic" (i.e., treated at 75-degrees C).
[The brochures show the results for the Penn State studies out to
year 3. None of the 5 deer in the SpayVac treatment group became
pregnant in that time. However, in years 4 and 5, 1 of the 5 did
become pregnant. That is still 80 % effective after 5 years, which is
quite acceptable in my view.]
This unfortunate glitch is bound to create confusion, but I wanted to
make sure that you were aware of the facts, because the newspapers
are almost certain to get it wrong!
All the best,
Mark A. Fraker
TerraMar Environmental Research Ltd
8617 Lochside Drive
Sidney BC V8L 1M8
ph: 250-656-3972 fx: 250-656-3474
TerraMar Environmental Research LLC
PO Box 126
Ashland OR 97520
ph: 541-482-8044 fx: 541-482-1486