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 BHW Resident Surgeon
Posts: 25351
  
Location: Bastrop, Texas | For those of us who believe in vaccines, one area where the practice of vaccinating needs to be cleaned up is establishing which vaccines should be given, in which parts of the country, and how often. Some say Rhino vaccines should be given every 3 months. That seems like overkill to me, but maybe there's something to be said for that.
Recently I have been challenged to produce proof that WNV vaccines actually work...ie: data.
The challenge is to read through the many articles and studies and then put it forth in a way that is easily understood. The statement was made that they were skeptical that the WNV vaccine actually works based on available research at the time. Back about 15 years ago up here we were hit with WNV hysteria that was well founded. One comment was "How come they haven't come out with a WNV for humans if the vaccine is so great?" It was a good question, so I was compelled to find something that was both understandable to a lay person and convincing at the same time. There is ongoing research into human WNV vaccines, but getting things like that approved by the FDA for human use is a very challenging, costly, time consuming project. The average new "pill" that comes out takes 10 years at an average cost of nearly $1 Billion even before it hits the shelf. Vaccines are even harder to study because of increased times required to evaluate the safety and efficacy. Anyway, the vaccine is on its way for humans, even though 80% of West Nile cases in humans are more flu-like illnesses.
Here's one good table that shows supports the notion of vaccinating horses against WNV, based on two groups of horses directly injected with WNV:
Vaccinated Unvaccinated Controls
Clinical Signs 10% 80%
Fever 10% 90%
Histology 10% 80%
(mild to moderate encephalitis)
WNV Viremia 0% 100%
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The Advice Guru
Posts: 6419
| HotbearLVR - 2014-05-04 11:51 AM
For those of us who believe in vaccines, one area where the practice of vaccinating needs to be cleaned up is establishing which vaccines should be given, in which parts of the country, and how often. Some say Rhino vaccines should be given every 3 months. That seems like overkill to me, but maybe there's something to be said for that.
Recently I have been challenged to produce proof that WNV vaccines actually work...ie: data.
The challenge is to read through the many articles and studies and then put it forth in a way that is easily understood. The statement was made that they were skeptical that the WNV vaccine actually works based on available research at the time. Back about 15 years ago up here we were hit with WNV hysteria that was well founded. One comment was "How come they haven't come out with a WNV for humans if the vaccine is so great?" It was a good question, so I was compelled to find something that was both understandable to a lay person and convincing at the same time. There is ongoing research into human WNV vaccines, but getting things like that approved by the FDA for human use is a very challenging, costly, time consuming project. The average new "pill" that comes out takes 10 years at an average cost of nearly $1 Billion even before it hits the shelf. Vaccines are even harder to study because of increased times required to evaluate the safety and efficacy. Anyway, the vaccine is on its way for humans, even though 80% of West Nile cases in humans are more flu-like illnesses.
Here's one good table that shows supports the notion of vaccinating horses against WNV, based on two groups of horses directly injected with WNV:
Vaccinated Unvaccinated Controls
Clinical Signs 10% 80%
Fever 10% 90%
Histology 10% 80%
(mild to moderate encephalitis)
WNV Viremia 0% 100%
Please state your reference | |
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BHW Resident Surgeon
Posts: 25351
Location: Bastrop, Texas | No problem, Cheryl. I can find more if you like:
Siger L, et al. Assessment of the efficacy of a single dose of a recombinant vaccine against West Nile virus in response to natural challenge with West Nile virus-infected mosquitoes in horses.
American Journal of Veterinary Research 2004;65(11):1459-1462.
8Paillot R, et al. Antibody and IFN-γ responses induced by a recombinant canarypox vaccine and challenge infection with equine influenza virus. Vet Immuno Immunopathol 2006;112:225-233. | |
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BHW Resident Surgeon
Posts: 25351
Location: Bastrop, Texas | Here's an abstract:
Abstract November 2004, Vol. 65, No. 11, Pages 1459-1462 doi: 10.2460/ajvr.2004.65.1459 Assessment of the efficacy of a single dose of a recombinant vaccine against West Nile virus in response to natural challenge with West Nile virus-infected mosquitoes in horses Leonardo Siger , DVM, MS Richard A. Bowen , DVM, PhD Kemal Karaca , DVM, PhD Michael J. Murray , DVM, MS, DACVIMPaul W. Gordy , MS Sheena M. Loosmore , PhD Jean-Christophe F. Audonnet , DVM, PhD Robert M. Nordgren, , PhD Jules M. Minke ,DVM, PhD Merial Ltd, 115 Transtech Dr, Athens, GA 30601. (Siger, Karaca); College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80552. (Bowen, Gordy); Merial Ltd, 3239 Satellite Blvd, Duluth, GA 30096. (Murray, Nordgren,); Aventis Pasteur, Connaught Campus, 1755 Steeles Ave, Toronto M2R 3T4, ON, Canada. (Loosmore); Merial SAS Ltd, 254 rue Marcel Mérieux, Lyon 69007, France. (Audonnet, Minke) Objective—To determine the onset of immunity after IM administration of a single dose of a recombinant canarypox virus vaccine against West Nile virus (WNV) in horses in a blind challenge trial.
Animals—20 mixed-breed horses.
Procedure—Horses with no prior exposure to WNV were randomly assigned to 1 of 2 groups (10 horses/group). In 1 group, a recombinant canarypox virus vaccine against WNV was administered to each horse once (day 0). The other 10 control horses were untreated. On day 26, 9 treated and 10 control horses were challenged via the bites of mosquitoes (Aedes albopictus) infected with WNV. Clinical responses and WNV isolation were monitored for 14 days after challenge exposure; antibody responses against WNV after administration of the vaccine and challenge were also assessed in both groups.
Results—Following challenge via WNV-infected mosquitoes, 1 of 9 treated horses developed viremia. In contrast, 8 of 10 control horses developed viremia after challenge exposure to WNV-infected mosquitoes. All horses seroconverted after WNV challenge; compared with control horses, antibody responses in the horses that received the vaccine were detected earlier.
Conclusions and Clinical Relevance—In horses, a single dose of the recombinant canarypox virus-WNV vaccine appears to provide early protection against development of viremia after challenge with WNVinfected mosquitoes, even in the absence of measurable antibody titers in some horses. This vaccine may provide veterinarians with an important tool in controlling WNV infection during a natural outbreak or under conditions in which a rapid onset of protection is required. (Am J Vet Res 2004;65:1459–1462) | |
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The Advice Guru
Posts: 6419
| HotbearLVR - 2014-05-04 12:01 PM
No problem, Cheryl. I can find more if you like:
Siger L, et al. Assessment of the efficacy of a single dose of a recombinant vaccine against West Nile virus in response to natural challenge with West Nile virus-infected mosquitoes in horses.
American Journal of Veterinary Research 2004;65(11):1459-1462.
8Paillot R, et al. Antibody and IFN-? responses induced by a recombinant canarypox vaccine and challenge infection with equine influenza virus. Vet Immuno Immunopathol 2006;112:225-233.
Thanks, if you have time can you look for some more current?
2004 is quite old, and the sample size was small, and I don't like that Meril, the vaccine manufacturer was involved, there may be some bias.
Thanks again for posting it.
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BHW Resident Surgeon
Posts: 25351
Location: Bastrop, Texas | cheryl makofka - 2014-05-04 1:52 PM HotbearLVR - 2014-05-04 12:01 PM No problem, Cheryl. I can find more if you like:
Siger L, et al. Assessment of the efficacy of a single dose of a recombinant vaccine against West Nile virus in response to natural challenge with West Nile virus-infected mosquitoes in horses.
American Journal of Veterinary Research 2004;65(11):1459-1462.
8Paillot R, et al. Antibody and IFN-? responses induced by a recombinant canarypox vaccine and challenge infection with equine influenza virus. Vet Immuno Immunopathol 2006;112:225-233. Thanks, if you have time can you look for some more current? 2004 is quite old, and the sample size was small, and I don't like that Meril, the vaccine manufacturer was involved, there may be some bias. Thanks again for posting it.
LOL....no, I don't really have time to look more up for you, Cheryl.
My goal wasn't to provide current, comprehensive, up to the minute research. My goal was to provide some "proof" that WNV vaccines are effective and to summarize it in a way that is concise and easily understood by most people. If you want to review more, by all means, be my guest!  | |
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The Advice Guru
Posts: 6419
| HotbearLVR - 2014-05-04 2:00 PM
cheryl makofka - 2014-05-04 1:52 PM HotbearLVR - 2014-05-04 12:01 PM No problem, Cheryl. I can find more if you like:
Siger L, et al. Assessment of the efficacy of a single dose of a recombinant vaccine against West Nile virus in response to natural challenge with West Nile virus-infected mosquitoes in horses.
American Journal of Veterinary Research 2004;65(11):1459-1462.
8Paillot R, et al. Antibody and IFN-? responses induced by a recombinant canarypox vaccine and challenge infection with equine influenza virus. Vet Immuno Immunopathol 2006;112:225-233. Thanks, if you have time can you look for some more current? 2004 is quite old, and the sample size was small, and I don't like that Meril, the vaccine manufacturer was involved, there may be some bias. Thanks again for posting it.
My goal wasn't to provide current, comprehensive, up to the minute research. My goal was to provide some "proof" that WNV vaccines are effective and to summarize it in a way that is concise and easily understood by most people. If you want to review more, by all means, be my guest!
Journal of Equine Veterinary Science
Volume 33, Issue 12 , Pages 1101-1105, December 2013
This is one I would love to read this is the abstract.
A 42-day study was conducted to assess the impact of three West Nile virus vaccines given either as separate injections or incorporated with their counterpart equine encephalitis and tetanus vaccines on serological responses under field use conditions. Two hundred forty mature, West Nile virus seronegative (<4) horses were followed serologically pre- and postprimary and secondary vaccination with six different vaccination programs, all including West Nile virus antigens. Forty horses were unvaccinated sentinel horses. All vaccines stimulated both a primary and secondary (booster) response to vaccination that was significantly higher than that of seronegative controls. However, inclusion of West Nile virus with equine encephalitis viruses and tetanus toxoid in vaccines had a significant detrimental impact on West Nile virus serum neutralization antibody production to both the primary and secondary vaccinations.
As a doctor you should know how fast research is discredited, or considered old. I would think you would critically analyze what you read to see if it is still pertinent, still creditable.
As you know the one research study on MMR was detrimental to immunization rates.
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BHW Resident Surgeon
Posts: 25351
Location: Bastrop, Texas | Cheryl, you said:
"As a doctor you should know how fast research is discredited, or considered old. I would think you would critically analyze what you read to see if it is still pertinent, still creditable. "
Why are you saying this? I don't see anything from this abstract that discredits my premise whatsoever. Do you?
If so, point it out, because I might be missing something.
All this tells me is that this study suggests that using the WNV vaccine in combination with equine encephalitis vaccine and tetanus toxoid vaccine may well result in an ineffective antibody response. This is good to know, however, nothing here says WNV vaccines are ineffective. This just tells me that it shouldn't be given in combination vaccines like 5-way, 6-way, etc.... This suggests the vaccine, when given alone, generates a much more vigorous response than when it is given in combination with the other two. That doesn't mean it isn't necessarily effective, rather, it isn't as powerful as it could be when given as a solitary injection. That's good to know and it may suggest that a single vaccine is all that is needed per year, rather than a fall booster, as is often recommended. I'm not sure if this study "discredits" anything.....but you can correct me if I'm wrong. I'm all ears! LOL This just promotes the idea that a monovalent vaccine, in the case of WNV, is probably preferable.
For me, I have always given my WNV separately, as a monovalent ("single antigen") so it's a moot point. I suspect, or at least I hope, that the components of the polyvalent vaccines have been similarly analyzed.
Good post, but as the saying goes, "True, true, and unrelated".
Edited by HotbearLVR 2014-05-04 5:30 PM
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BHW Resident Surgeon
Posts: 25351
Location: Bastrop, Texas | Oh, I forgot about this remark you made:
"As you know the one research study on MMR was detrimental to immunization rates."
Which "research study" are you referring to? I'll let you work on that for a while. I'm curious as to what you are talking about. | |
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Elite Veteran
Posts: 620
Location: Bixby, Ok | Here let me help. The study Cheryl is referring to does show that WNV vaccine when combined in the same syringe results in a lower sero conversion number than when introduced as a single antigen. However, the sero conversion numbers were still considered protective based on previous studies where horses were injected with active WNV. In this study the horses were privately owned and therefore could not be used as guinea pigs so to speak. This was simply to determine the difference between single antigen vaccines and multiple. There are many theories out there as to why this occurs. Simply put for convenience most clients want their horses stuck as few times as possible. Hence the multi-antigen vaccines. However, it has been shown over and over that single antigen vaccines do give a better amnestic response period. But that would mean more needles and higher vaccine costs. Again I stress that the level of antibodies produced were in the range that previous studies have shown as protective. Is a higher level of protectivity better you bet but there are pros and cons to everything! Also their study was paid for by Zoetis formally FT Dodge so why not be concerned about their bias? Now Zoetis will tell you and have had every meeting that I have been too. All vaccines out there despite manfacture have been proven to give a protective level of protection and I applaud their efforts to be neutral In These studies. I just set through a 3 hour ce meeting in which this particular study was presented. I find it very interesting that we have proven multiple antigen vaccines are less effective and we couple not only multiple antigens but also multiple antigen and multiple vaccines on children running a fever. I slowed my daughters vaccines down immensely and was looked down upon for it. However, I was informed by her school on Thursday that my child and the other two children in the school that were not vaccinated on schedule are actually the healthiest 3 kids in school they have between them missed an average of 6.2 days less per year than their completely vaccinated count parts. Made me go hum for sure. It was brought to my attention by the school nurse because she was upset about my choice at first and now wanted to know what I knew and understood that she didn't lol. I know horses and humans respond diff but similarly to vaccines and I personally feel that multiple vaccines all at once may very well overwhelm at least for a short time the immune response. In The vet world the take home from the above mentioned study is that horses respond better to single antigen shots administered by themselves. Ie not even several single antigen vaccines on the same day. However, in some instances this is not practical and this study did show that muti antigen vaccines do get a protective level. However, due to findings in this study more studies are currently in the works and splitting injection sites for vaccines. Ie administering 1/2 in one site and the other 1/2 in another site has also improved protectively levels. More about those studies findings as they become available. Hope I cleared the water a bit. Edited for spelling errors.
Edited by BR-DVM 2014-05-04 5:50 PM
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BHW Resident Surgeon
Posts: 25351
Location: Bastrop, Texas | Thank you! I was going to try to explain why multiple antigens injected as a polyvalent vaccine results in a lower titer of each antibody, when compared to the titer if those antigens are given as a monovalent vaccine, but I can't come up with a real good, simple explanation.
My point to begin with was that I tried to come up with an understandable explanation of studies that support the notion that WNV vaccines "work", hence, that little "table" that I posted. It seems we have drifted a bit from there, but that's OK. It's all interesting. Is this what they mean by "antigenic drift"? .LOL....corny, I know.
As far as human vaccines etc..., we can go into that, but maybe a separate thread would be better. | |
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Elite Veteran
Posts: 620
Location: Bixby, Ok | I agree 100% this thread has went somewhere besides where it was intended lol but however correct info can get out I'm just glad it does. I had an interesting experience this morning with a person who thought they knew and realized they didn't lol. We bought a new puppy at the rodeo and the people camped just across from us did also. Their puppy pooped blood today so she gathered up her hot penicillin and injected a 2.5 times too much dose into the muscle of this poor puppy. Then proceeded to put the same needle back into th bottle and come to our camp site and say. Our puppy pooped blood and we gave penicillin we need to give your puppy a shot too. I not so nicely asked her whe her DVM degree came from and explained that sh was not going to use a contaminated needle or pen on my puppy. She left but came back shortly to apologize and to tell me she should have given baytril instead. I then explained baytril is contraindicated in young animals and maybe a tip to her vet rather than diagnosing and treating on her own was a better choice. SMH. Maybe I saved her next puppy from an overdose of pen I the muscle. Pen in small animals is usually administrative under the skin. | |
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BHW Resident Surgeon
Posts: 25351
Location: Bastrop, Texas | Oh boy don't get me started! How many times have I seen people re-use the same needle, and not even bother cleaning the injection site!
Why do people seem to think that horses don't benefit from standard, basic aseptic precautions. It's basically just laziness. No wonder so many horses get abscesses at injection sites. | |
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Hungarian Midget Woman
Location: Midwest | HotbearLVR - 2014-05-04 6:37 PM Oh boy don't get me started! How many times have I seen people re-use the same needle, and not even bother cleaning the injection site!
Why do people seem to think that horses don't benefit from standard, basic aseptic precautions. It's basically just laziness. No wonder so many horses get abscesses at injection sites. Reusing needles...really... come on folks
the stuff is super cheap
PS
Edited by barrelracr131 2014-05-04 6:43 PM
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BHW Resident Surgeon
Posts: 25351
Location: Bastrop, Texas | Terri, you are a vet, and I would like to ask you something. Knowing what you know about this EHV-1 outbreak up here (upper midwest), would you personally haul to several barrel races while this is going on? | |
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Elite Veteran
Posts: 620
Location: Bixby, Ok | No Scott I would not haul in that region period. For 21-30 days. My horses mean more to me than that and there are other barrel races soon enough. | |
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Elite Veteran
Posts: 620
Location: Bixby, Ok | We were at the BBR finals and that was a ill nerve racking due to the Lincoln horses. I just hope it gets hot enough to help kill this. We are continuing to haul but we are in ok and been going to jr rodeos where most stay local and def staying away from everybody as much as possible. I know there is always a chance but the chance is greater when there are a lot of horses under one roof and in tight quarters such as at Lincoln and BBR. But at least at OKC the stall are solid between horses. I hate these kinda of outbreaks very hard to contain and stop this day in age | |
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BHW Resident Surgeon
Posts: 25351
Location: Bastrop, Texas | Thanks. That's what I figured. | |
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  More bootie than waist!
Posts: 18425
Location: Riding Crackhead. | BR-DVM - 2014-05-04 8:23 PM We were at the BBR finals and that was a ill nerve racking due to the Lincoln horses. I just hope it gets hot enough to help kill this. We are continuing to haul but we are in ok and been going to jr rodeos where most stay local and def staying away from everybody as much as possible. I know there is always a chance but the chance is greater when there are a lot of horses under one roof and in tight quarters such as at Lincoln and BBR. But at least at OKC the stall are solid between horses. I hate these kinda of outbreaks very hard to contain and stop this day in age
I'm so glad we have a vet on the boards to finally answer some questions. No one seems to know if the horses that have been affected and put down by EHV1 were vaccinated. In your opinion do you think the vaccinations help? Do they need to be repeated every 90 days? Last week Dr Scott asked if he should go to a pole bending, not stay over, just jump out of the trailer and run, go home and don't stall there. I'm being faced with the same thing this next coming weekend. They aren't refunding our money, I have $520 invested and I'm wondering if I should just take it in the shorts or how safe do you think it is to stay off grounds but yet we're running indoors. This all seems like Russian Roulette to me. Your thoughts? | |
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Elite Veteran
Posts: 620
Location: Bixby, Ok | It is Russian roulette and I would not be putting my self in a position to be close and inside in the hot zone. As heat and sun exposure helps eliminate exposure via buckets and stalls it doesn't protect against one blowing their nose around you warming up or waiting to run. As I stated w are continuing to haul but we have had. I issues here and we are. It running inside and at large events minus BBR which was actually kinda going before the big issue and picture became clear. I might and most likely would have skipped and I had 1100 invested. But my horse cost much more than that. | |
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