[Buffy the eggs layer]

I am due to vac my lambs in a week or so and I have often wondered what actually happens to opened Hep P after 10 hours?


Does it loose all its properties? Does it gradually start to reduce in effectiveness? Do only some of the vacs within the combined product become ineffective?


I use it 3 times a year for pre lambing, lamb vacs and boosters and always find myself wondering if this 10 hour thing is just a conservative estimate/ recommendation by the manufacturers or If I used it 11 hours after opening it would my lamb turn into a pumpkin? 


Farmvet do you know ?


I have worked out a way to avoid wasting half the doses in the bottle by the way though......buy more sheep!

[Crbecky10]

I think it is just a manufacturer thing, keep it in the fridge when you're not using it and give it a good shake before using, it always seems fine! 

[princesslayer]

We had a post on this a few weeks back where a learned person stated that after 10 hours it was worthless, like water. I'd like to know the science behind that. Is it the opening of the bottle/breaking the seal?

[harmony]

Yes, that's right. Someone with a scientific background said after 10 hours of being opened you may as well inject water for what use the vaccine would be, as it was well known in science circles vaccines don't work after 10 hours of being opened.

I think but can't be sure that it was something to do with the solution the vaccine lives in that isn't viable after ten hours of being opened so the vaccine dies.

If the manufacturer says use before 10 hours why do people say it will be fine sealed up and kept in the fridge? Surely the manufacturer should know?

[harmony]

Here is the post previously on Heptavac!







Re: HeptavacP Plus
« Reply #5 on: January 23, 2015, 05:31:45 pm »
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Quote from: Jukes Mum on January 23, 2015, 03:05:15 pmObviously you should buy a whole new bottle each time but I do recall discussion that the 'use within 10 hours' was just because the vaccine's efficacy had not been tested beyond this.



I am a farm vet looking at lots of dead lambs every year, mostly of clostridial disease and pasteurellosis, and would never ever risk vaccinating them ineffectually with a vaccine that has been opened for weeks. It really does go off, the drug companies don't test it because there is no point in doing so - purified proteins do not last and they are not going to spend money to show something they already know (this comes from someone - me - who's done a PhD on protein purification).
Some bacterial proteins might last a few more days than others but all slowly degrade sooner or later and if you inject with a bottle open for more than 12 hours or so you are just wasting time as it is fresh water by then.

If your lambs are not going to be kept for breeding I would advise to keep the [/color]Heptavac P for the ewes booster and give Ovivac P or Lambivac to the lambs (2x injections full course). These two are cheaper than Heptavac.
Also as already suggested, you need to find someone near you that is willing to share the cost of the bottle and that way you can all gain. Worth asking your vet if they know anyone in your same situation, we put people in touch for this reason all the time.[/font][/color][/size]

[devonlad]

If the manufacturer says use before 10 hours why do people say it will be fine sealed up and kept in the fridge? Surely the manufacturer should know?

so they can sell more ? 
our vet has assured me that provided its not contaminated by using multiple needles and is sealed again promptly and stored in fridge then there is absolutely no reason not to use it again for second jab. weve been doing it for years

[harmony]

If you don't trust the manufacturer why buy the product?

[princesslayer]

I can see the whole degradation of proteins thing, but why wouldn't they do that straight after manufacture? What is it about unsealing the bottle that makes the proteins suddenly degrade? Why don't they degrade in transit? Wish Welshcob would come on and explain more!

[devonlad]

If you don't trust the manufacturer why buy the product?

Oh blimey !- "trust" !!! wasn't particularly aware it was really about trusting or not trusting.
when it comes to keeping animals we discovered long ago that if you "trust" every piece of advice given, no matter how qualified and experienced the giver of that advice, you soon end up going in ever decreasing circles. the world of animal husbandry seems riven with endless conflicting advice. Our first couple of years were characterised by us trying to follow all advice given, which ultimately proved frustrating, costly and impossible. Nowadays we do what we have always done and seek out advice from our vet, TAS and a range of local contacts and then we sit down and decide which of these often vastly varying nuggets we actually follow. In the end we take a decision based on trying to do the best for our animals without being unnecessarily wasteful and making our expensive hobby even less sustainable. There is a debate as to whether Heptavac P is even necessary or effective and many don't, but we do , in our way, (probably because we're afraid not to) and for now its worked. if it stops working then its back to the drawing board

[harmony]

Absolutely Devonlad everyone will make their own mind up but so far we have a scientific explanation of why after 10 hours the product won't do it's job, then people who say they use it after this and that their vets say it is ok to do so but no scientific explanation of why it is fine to ignore the product data.


Maybe someone can ask their vet why they are right and whether those selling a few doses here and there from a bottle guarantee it's effectiveness.

[Bionic]

My vet says its only effective if used within 10 hours. They split the use of other products i.e. wormer but because the Hep vac needs to be used quickly won't sell it, other than in the unopened bottle form.

[Hellybee]

The way I see it is that it's not expensive to buy, we use it up and don't leave a bottle to use again.  Not worth the risk.

[Marches Farmer]

We were advised by our neighbour (widely acknowledged to be an excellent farmer) to use Ovivac P Plus because it was cheaper than Heptavac, pierce the lid once only with a sterile needle and draw every dose off through this then withdraw the needle, seal the top with a piece of Sellotape, put it back in the fridge as soon as we finished with it and carry on using it until the bottle's empty.  His lamb losses are down to predation by badgers and foxes, not the diseases Ovivac protects against. 

[Fleecewife]

We don't vaccinate so I'm not familiar with the handling of Heptavac.   The only reason I can think of that a vaccine would degrade after opening is because of exposure to oxygen.  On the other hand, it could be that any contamination reacts quickly with the product itself to degrade it, and however clean you are it is almost impossible to guarantee no contamination has taken place.

I have no idea if this is the case or not, just thinking.

I do though find it unrealistic to imagine that the product is fine to use 9 hours and 59 mins after opening, but suddenly transmogrifies into water on the dot of 10 hours - coaches into pumpkins indeed.

Probably the only definitive way to get an answer is to contact the manufacturer and ask for a full scientific explanation.

[harmony]

Marches Farmer Ovivac has the same 10 hour shelf life as Heptavac after opening. I'm glad your neighbour only has losses due to predators but that still doesn't answer why the 10 hour shelf life should be ignored.


Fleecewife I see your point about the cut off point and I'm sure it was reached the manufacturer having an understanding of their product but it's rather like common pain relief tablets that you can't give to children under 6. Do we wait until they are 6 tomorrow or give them it today when they are still 5?


You can see that the product might well be ok for a bit longer than 10 hours but days or weeks?