Vaccinate or Not

[FortCluck]

Who gets their chicks vaccinated...

Why or why not

Answer poll then comment you opinions below

 

[ChocolateMouse]

I don't vaccinate my chicks.

I want strong genetics in my flock. So vaccinating doesn't help with that. I really want natural immunities.

The one vaccine I would give, salmonella, has been maligned by the FDA because it's ever so slightly different that the one used in Europe because of our regulations. I would give my chickens the salmonella vaccine were it a viable option but with no public support it's expensive, nobody's educated on it, it's not well-approved by the FDA and therefore it's largely not helpful to do.

Most diseases you can vaccinate for like Mareks the vaccine doesn't actually provide immunity it just hides the symptoms of an otherwise still-sick bird. In fact vaccinated but infected birds actually spread the disease more, not less.

Ultimately if the vaccine doesn't produce a sterile immune response I don't want it anywhere near my flock. That way I can know if my chickens are actually sick or not.

 

[Kiki]

Vaccinated for what?
There are different things one could vaccinate for.

I do not nor would not vaccinate for anything.

 

[21hens-incharge]

I do not vaccinate.
My flock is small and for me the disease risk is low.

I also do not want to risk a carrier in my flock.

 

[Mixed flock enthusiast]

We’ve only had poultry for about two years, and my knowledge of Marek’s disease virus (MDV) was pretty superficial at the beginning. I knew about Marek’s but thought it was rare in backyard flocks. I did inoculate our first group of barnyard mix chicks that we hatched with the common, acellular HVT (herpesvirus of turkeys) vaccine. We then purchased two separate groups of purebred chicks from a local, well-known breeder who did not vaccinate but “bred for resistance”. We lost only a few chicks from the first breeder group, but most chicks from the second group died before 2 mo old. At the same time, we started losing older juveniles from the first, POL breeder group. Picture is of Lemonhead, 5 month old East Frisian Gull cockerel, our first bird diagnosed with Marek’s. State lab necropsies showed that all dying birds had Marek’s, which weakened their immune system so some died from coccidiosis or other diseases. Current day, more than a year after buying those two sets of breeder chicks, we’ve lost almost all of those breeder birds at various, vulnerable times: chicks, POL, maturing roosters, after fights, after treating mites, etc. We’ve lost none of our original, backyard mix, HVT vaccinated birds. We now only buy chicks that have been Rispens strain MDV vaccinated, or I vaccinate with Rispens as eggs at day 17-18 if we are breeding them. We don’t sell or rehome chickens. We’ve lost none of these vaccinated, broody raised chicks (knock on wood) which are now POL or just past laying age, even as we’ve continued to lose our unvaccinated chickens.


As for the numerous news article mentioned earlier about Marek’s vaccination leading to hotter strains of virus, those all refer to the same study. That study does suggest that our huge, commercial poultry houses have indeed engaged in a biological arms race between MDV and its vaccines. However, what it shows is that, IF chicks contract the most rapidly lethal strain of MDV, termed highly pathogenic or very virulent Marek’s disease virus (vvMDV), then the vaccine protects them long enough that the virus has time to replicate and be shed by those birds, potentially infecting other birds. IF they are not vaccinated, then they all die so fast that the birds don’t have time to shed virus.


Instead of reading the news articles about the study, go to the actual study, which is freely available at: https://www.ncbi.nlm.nih.gov › pmcWeb resultsImperfect Vaccination Can Enhance the Transmission of Highly Virulent Pathogens

Look at Figure 1, which shows three different outcomes of interest, from top to bottom: percent of chicks surviving after MDV inoculation, MDV shedding over time, and cumulative or total amount of virus shedding over the time that the birds are alive. The unvaccinated groups have dashed lines or lighter color shading. From left to right, we have MDV of different virulences, from mildest to hottest. The first, HPRS-B14, is an older, less virulent MDV where “only” 60% of chicks die. The last strains, like Md5, are vvMDV, where all chicks die. If you have a less virulent MDV, then both vaccinated and unvaccinated chicks get infected and spread virus. But, the vaccinated chicks shed LESS virus, because the vaccine kicks up the immune system of vaccinated birds so they fight viral replication. In addition to shedding less virus, the vaccinated chicks are more likely to survive. IF your have a hotter, vvMDV strain, then just the fact that the vaccinated chicks survive means that they are still capable of shedding virus. The unvaccinated chicks are all dead, so no virus shedding is going on there.


My take on this: Considering that there are probably few chicken flocks that are really MDV free, it makes more sense to me to vaccinate and increase the likelihood that our birds live when a hotter virus strain makes its way to us. Backyard flocks aren’t the ones driving this evolutionary arms race, and we aren’t able to escape it either.

 

[21hens-incharge]

Do you risk creating a carrier by giving the vaccine?

My understanding is it can. Not necessarily CREATE a carrier but allow a sick bird to not show symptoms while still shedding (and thereby sharing) the illness.

 

[FortCluck]

I don't vaccinate my chicks.

I want strong genetics in my flock. So vaccinating doesn't help with that. I really want natural immunities.

The one vaccine I would give, salmonella, has been maligned by the FDA because it's ever so slightly different that the one used in Europe because of our regulations. I would give my chickens the salmonella vaccine were it a viable option but with no public support it's expensive, nobody's educated on it, it's not well-approved by the FDA and therefore it's largely not helpful to do.

Most diseases you can vaccinate for like Mareks the vaccine doesn't actually provide immunity it just hides the symptoms of an otherwise still-sick bird. In fact vaccinated but infected birds actually spread the disease more, not less.

Ultimately if the vaccine doesn't produce a sterile immune response I don't want it anywhere near my flock. That way I can know if my chickens are actually sick or not.

Yes! Natural immunity is something I'd rather have too

 

[CSAchook]

With those theories no one should get vaccines because it makes the diseases stronger. I never get a flu shot anyway.

Not true. You cannot compare Marek's vaccines to the ones humans get. Most vaccines (for humans and animals) prevent the recipient from ever contracting the disease. The Marek's vaccines (there are several) are different. They do not prevent the disease. They only prevent the worst of the symptoms.

That is why wide spread use of human vaccines has lead to the complete eradication of some diseases, while Marek's vaccines have arguably just led to the development of more potent strains.

Also, get a flu shot!

 

[Kiki]

Some of the types of vaccines:
https://www.jefferspet.com/categories/poultry/health-wellness/poultry-vaccines

 

[CSAchook]

My last batch of hatchery chicks were vaccinated for Marek's. I was splitting the order with my Dad and he has a Marek's positive flock. It was introduced to the property by wild birds. He now keeps a closed flock (once birds go in they never leave the property) but he would like his girls to live as long as possible. (For those that do not know, Marek's fatalities are most common in POL and very old birds.) Raising chicks and losing 30% of them at POL was depressing to say the least. And breeding for resistance is not an option for him because he lives in the city and cannot keep a rooster.

So the chicks I kept were also vaccinated. It left me with a flock of vaccinated and unvaccinated birds which I had no problem with.

Coccidiocis was the only other vaccine the hatchery offered and I felt that was unnecessary for my climate and flock size.

To be clear, getting Marek's vaccinations doesn't prevent my Dad's birds from contracting Marek's. It just keeps them from dying of Marek's. They are still carriers for the disease which is why he keeps a closed flock.