[Buffy the eggs layer]

Hi Everyone,


  seems I'm not the only one who has wondered what actually happens to the vaccine and why so thanks for posting the previous thread. I know lots of people who dont inject and dont have problems but personally I'm happy to buy the product and follow the instructions.


 I was just genuinely interested to know what happened and why. In reality the drug probably starts to deteriorate after around 12 hours unless all sorts of precautions are taken to preserve it for an additional hour or so extra and to ensure that we can trust in the products effectiveness, the manufacturers give a conservative estimate of its life span as 10 hours to be on the safe side.


My vets actually operate a system of opening a bottle in the surgery and the receptionist coordinates smallholders with small flocks to call in and take a syringe full home to inject straight away. I have always preferred to buy in my own vacs from the feed merchants and do my own when it fits in with me but it's a good idea for smaller flocks of just two or three.

[Marches Farmer]

Would it make a difference if the vaccine were live or killed?  My neighbour has around 400 ewes and doesn't run a closed flock, nor does he alternate turnout fields, so I would have expected the challenge to lambs to be quite high ....?

[Me]

  His lamb losses are down to predation by badgers and foxes, not the diseases Ovivac protects against.

Possibly/probably are true predator kills but often hard to tell the difference between those killed and those freshly dead and scavenged or nearly dead scavenged sometimes

[lord flynn]

also a scientist for my sins and work in vaccine antigen production (not Heptavac). Heptavac isn't a live vaccine, its toxoids and killed cells.

It is an incredibly difficult thing, to get a vaccine (especially one with multiple components) to behave exactly how you want it to over time in storage. Then you have the problem of how the vaccine is handled when opened. Any contamination, as Fleecewife  said, could cause degradation/contamination-which at best would leave the vaccine less efficient and at worst (depending on what was the cause of the contamination) kill the sheep or cause a nasty infection. It also states it must be kept in the dark so an element could be light sensitive, it might be temperature, it might be air. There are so many variables as to what people might do with the vaccine once they have it, its better that the company says to use it within an allotted time to cover their backs and of course, there may not be any difference between 11 or 10 hours. There will be a reason for stating the 10 hours-it may just be that it hasn't been tested past 10, or conversely maybe there was no need as efficacy was too damaged at 10 hours.I doubt the formulation is as water after 10 hours but this is not done to pee people off and its not to get you to buy more. If the vaccine were proved stable for months, it would be priced accordingly.  It's a vaccine, I don't understand why people would do anything other than instructed tbh

[farmvet]

I agree with you completely Lord Flynn.  Another issue I can see is that most TAS members will be storing vaccine in domestic fridges rather than proper vaccine fridges which agri merchants vets etc have to use. Temperatures fluctuate in ordinary fridges & this can further damage vaccines. Best practice is to purchase vaccine as near to when you need it as possible, transport it in a chiller box & discard it at the end of the day.

[Marches Farmer]

The vaccine manufacturers don't actually say what tests their vaccine has been put through.  Just to play devil's advocate may I point out that if you don't test for efficacy after 10 hours you can't say whether it does, or does not, remain effective?

[lord flynn]

The vaccine manufacturers don't actually say what tests their vaccine has been put through.  Just to play devil's advocate may I point out that if you don't test for efficacy after 10 hours you can't say whether it does, or does not, remain effective?

no, but they do have to tell the VMD what they did-and for the patent. And I don't think the manufacturers are the ones saying anything other than don't use it after 10 hours of opening. At least, not on the info on Heptavac Product Data Sheet that I've seen. Do you think they don't think these things through? If they did let people use it without testing or a caveat, people would do all sorts of daft things with it (with a good point made about domestic fridges-ours are work are checked daily and are alarmed, records kept for 5 years!)-then the vaccine might be be less effective for whatever reasons. The product gets a bad name and millions go down the tube. If the vaccine were stable for long periods of time after opening, it would be more expensive. Companies do huge amounts of research into how to cost products up.


To test the efficacy of this product over time would mean further repeated animal vaccine trials and challenge experiments-hugely expensive and arguable ethically when people could just do as instructed.


I get a bit annoyed at everything drugs companies do as being seen as a conspiracy theory to rob people blind-especially in vet medicine lol where the margins are generally tiny. Products are engineered/thought up/researched by people who are highly motivated by animal health and welfare and excited by the science of it.

[Hellybee]

I m very much inclined to listen to the scientists.  I ll say it again, it's inexpensive, even with a small flock it's less than a pound a head.  Why save it, use it up.  Buy fresh when you need it.

[Buffy the eggs layer]

Thanks to all the experts for your knowledge. I jab my flock all at the same time and use up the best part of a bottle witing half an hour so the 10 hour expiry is never reached for me.


I also keep it in the spare fridge in the workshop which is not used for anything else so dosent experience the fluctuations of the kitchen fridge.


I have never doubted that the vaccine was ineffective after 10 hourse I just wondered why that was. Thanks for all your answers.

[devonlad]

I would be fairly daft to try to disagree with the wealth of experience and qualification on here. As I said previously we only took a more cost effective route after outmr much trusted vet told us no need to bother with buying a new bottle. By the way if we had bought a new bottle for 2nd jab it would have cost us £6 a head and we would have thrown 41 doses away

[Buffy the eggs layer]

Devon lad


              not sure how many sheep you keep but you can get a 50ml bottle which gives you 25 doses so you wouldn't be throwing so much away.
 

[devonlad]

Yes I would thus year just got 7 ewea and 2 ewe lambs. First bottle of 25 doses 18 thrown away. 2nd bottle for 2 ewe lanmbs 2bd jab 23 doses rmtgriwn away. 41 doses thrown away and 9 used

[Hellybee]

Ahh Devon lad, I see what you mean, you ll just have to buy more sheep then     Bit of a bigger being in that situation, but still a good thing to do. 

[Jukes Mum]

Buffy the eggs layer- you are very local to me. I am due to vaccinate 4 lambs on around the 25th (ish). Could we share a bottle?

[Buffy the eggs layer]

Jukes mum


  Im due to give my first lot on 11th. ( Health permitting as I have pnumonia again! ) and the next lot on 9th May. I have got a bottle in the fridge for this months jabs and have 12 lambs to vaccinate so you are welcome to come over for the remainder if you can make use of it.