New Strategies for Vaccination Prevention in the Poultry Industry

As part of the educational project "In Cuba" (ID "Sphere"), Eduard Javadov held a webinar "New Strategies for Vaccination in Poultry" and answered questions from the audience. 

- I'll start with a provocative question that Sergei Rudenko, veterinarian, poultry farm "Kuzbass Broiler" asks us: We invent a vaccine against influenza, and then ban it - where is the logic? 

- The question is actually provocative, maybe debatable. Bird flu vaccines have been developed since the 1970s. In the Soviet Union, a blood-sorbed vaccine was made for the first time. When the problem of bird flu started in 2004–2005, the Veterinary Institute of Poultry Farming, which I then led, immediately suggested to the Russian Academy of Sciences and ROSSELKHOZNADZOR that we could make a vaccine, and we did. Few people believed in it, we tested it - the vaccine works. After that, the Stavropol Territory did, ARRIAH and many people developed it. 

But today, in industrial farms, vaccination with vaccines from the H5 serotype, namely the fifth hemagglutinin serotype, of the avian influenza virus is prohibited. 

We periodically either allow or ban. This policy is incomprehensible to me, I believe thatRUSSIA will come to the need for vaccination against bird flu. Countries that have come to vaccinate have an effect. In CHINA, where most birds are raised, they vaccinate all the birds and they see the effect. Israel, Mexico, many CIS republics, including Kazakhstan, are vaccinated. 

Some scientists argue that vaccination will not help us, but, on the contrary, will hide the infected bird, because the antibodies will be in both the vaccinated and the infected bird. But this is the wrong position. 

Vaccine opponents demand 100% immunity, and the current vaccine does not create 100% immunity. But not a single vaccine creates 100% immunity: neither avian, nor cow, nor human.

But it is necessary to vaccinate against bird flu. 

If we talk about the fact that we will not protect 100%, therefore we will not vaccinate, but we will only carry out the Stepping Out program, then let's refuse to vaccinate bronchitis and Marek, Newcastle, there is no 100% immunity for all these vaccines. 

We have any bird on any farm against Newcastle disease vaccinated. But every year we open unfavorable points for vaccinated poultry. I repeat, it is necessary to vaccinate, but it is right to approach this. 

I never said that you just need to vaccinate 100% of the entire livestock, all over the country at once. It is necessary to take into account the seasonality of this pathogen, it is necessary to take into account the danger of a particular region, take into account the migration routes of migratory birds. We know about this, epidemiologists know about it, and they are developing vaccination against human influenza with this in mind. Before the flu hits England, they're already vaccinating just like we do, knowing what's going on in Southeast Asia. 

I repeat, I do not agree with this position that it is not necessary to vaccinate, because we will not protect 100%, and then we will not distinguish the vaccinated from the unvaccinated. 

There are methods to distinguish vaccinated birds from unvaccinated ones. And the method for determining neuraminidase antibodies, and the so-called guard or sentry, various methods, the Diva program, which allows you to distinguish vaccinated birds from unvaccinated ones. 

— How to take samples correctly for the identification of influenza virus by PCR, are FTA cards suitable, is there a program for monitoring low pathogenic avian influenza on broilers and laying hens? How long after infection with low pathogenic avian influenza will we see antibodies in the ELISA? 

- FTA cards can be used to select organs and conduct molecular biological research methods. The monitoring program for both low-pathogenic and highly pathogenic influenza is a program that the Rosselkhoznadzor approves, and they say whether it is necessary or not to carry out serological and virological monitoring. Today we can monitor the manifestation of highly pathogenic and low pathogenic influenza. Most often, this is done by serological methods in various laboratories and poultry farms, a certain number of samples are taken. If there is trouble this season, and this region is unfavorable, then the Rosselkhoznadzor will declare and say - send so many samples. 

How can poultry farms do this? It is possible to take blood serum and pathological material, in FTA cards or simply frozen pathological material, send it to the laboratory, and ask in a cover note to confirm or exclude the presence of a particular virus. In this case, avian influenza, highly or low pathogenic. True, I rarely saw veterinarians who themselves voluntarily wanted to do this. 

Veterinarians can also check on their own, in poultry laboratories, by taking a blood test and checking for the presence of antibodies, either by enzyme immunoassay or by the method in the hemagglutination delay reaction, antibodies can be detected and confirmed whether the virus has entered the farm or not. 

In this case, I mean farms that have not been vaccinated against avian influenza. And not a single farm is vaccinated against highly pathogenic influenza in the Russian Federation. 

— Eduard Dzhavadovich, could you give some recommendations on how to build a vaccination program for young chickens on a site that is unfavorable for GP H9 and Newcastle disease of the seventh genotype. The site is old, there is no possibility of observing "empty - busy", since adult birds and young Rhemes are located at a distance of 30 meters, common transport and personnel contribute to the early introduction of the pathogen into the poultry house. Specific prophylaxis for Newcastle disease of the seventh genotype is not considered, due to the lack of registered vaccines in the Russian Federation. 

— It is necessary to draw up a vaccination program and start with maternal immunity. Parents must be vaccinated with the vaccine that is currently approved and recommended by the Institute for Animal Welfare. I mean H9 flu and Newcastle disease. Parents a month before the start of oviposition should be vaccinated with this vaccine so that there is intense maternal immunity in chickens in the first days of life. 

Unfortunately, I heard not very high-quality reviews on this vaccine, there is not low immunity, and it still slips on H9, we vaccinate, but still this H9 flu exists. Both pathogen and antibodies are detected. 

The vaccine may not have been fully developed. The Institute for Animal Welfare has excellent biotechnologists, they had to develop a vaccine that would allow one to develop a fairly high immunity. Antibody titers should be higher than 1/1024 one month after vaccination. Then this immunity will last for a long time, and maternal antibodies will protect the chickens. 

If we talk about Newcastle disease of the seventh genotype, then most scientists will answer that vaccinate "Losoto" and that's okay. This is the first genotype, but antibodies do not differ serologically from an antibody of the seventh genotype from antibodies against the first genotype. In fact, the serotype is one, the genotypes are different. 

The authors who talk about this are theoretically right. But, unfortunately, this has not been proven in practice. I met with the manifestation of Newcastle disease caused by the virus of the seventh genotype in some regions of the Central Asian republics. They vaccinated with the first genotype, vaccinated mainly with Losoto, some even vaccinated with the H strain, which is currently prohibited in the Russian Federation. But this is a strong virus that causes high immunity. For some reason, the virus of the seventh genotype, antibodies against the first genotype, do not work and it manifests itself. 

I don’t fully know why, although any scientist will say the serotype is the same - antibodies will work. But practice shows that it does not always work. 

Unfortunately, there is no such vaccine in Russia. I know that few people in the world produce a vaccine from the seventh genotype. SOUTH KOREA is doing and getting a significant effect after using this vaccine. I believe that our scientific community is able to solve this problem and develop a good vaccine from the seventh genotype, and use it to prevent Newcastle disease. I do not want to be a black seer, but this problem will appear in the Russian Federation. Or rather, it is already there, and it will expand, and this problem with Newcastle disease caused by the genotype seven virus will cause us a lot of anxiety. 

— Eduard Dzhavadovich, could you tell me, please, what is the simple scheme of vaccination for household plots of 200 chickens? It is rather difficult for a non-professional - an amateur to understand all the subtleties, tell us about the necessary minimum. Maybe there is a vaccine for several diseases at once? Is vaccinating chickens different from turkeys? And the third question: is it necessary to vaccinate pheasants, they live separately from other birds, but contact with forest birds is possible? 

- Much depends on what kind of bird it is with 200 heads: a laying hen or is it a broiler? If this is a broiler that lives only in the household plot for 30-45 days and then it is slaughtered, then it just needs to be vaccinated, Newcastle is a must, maybe bronchitis. 

If this is a laying hen, then it is necessary to vaccinate Marek as well. All the rest: mycoplasma, reavirus, infectious anemia, this is a pneumovirus, omit all this. Here, at least these three infections: these are bronchitis, Newcastle and Gumboro, it is necessary to vaccinate both broilers and laying hens. 

If this is a laying hen, then add more Marek's disease at a daily age. 

How to vaccinate? You need to call a veterinarian. 

When to vaccinate? It is necessary that the veterinarian check the presence of maternal antibodies in the blood serum, and say: the first days are not necessary, because maternal immunity is still active, and there, by the 15th day, maternal immunity against Gumboro disease is gone, you need to enter the vaccine. 

To develop a vaccination program in each specific case, you must first look at which bird and what antibodies are there, what were the parents vaccinated with?

It is better not to keep turkey and pheasants nearby, as you are talking about. Even if you have a laying hen and a broiler, you can’t keep them nearby either. They should all be separated, each type of bird should be kept separately. But if you have a turkey at a distance, then in the Russian Federation I would definitely vaccinate a turkey with at least hemorrhagic interitis of turkeys. 

There is no such Russian vaccine, but the French vaccine "Dindaral" is registered in the Russian Federation. It is, however, expensive, but soldering can be used. All other diseases are Indian, I would not use it, I would not even use mycoplasmosis. If you have 50-100-200 heads of turkeys, you should not enter with a large baggage of vaccinations. Hemorrhagic enteritis on turkeys is enough. 

If we talk about pheasants, then this is the same vaccine against hemorrhagic enteritis of turkeys, or in another way it is called against the speckled spleen of pheasants. The virus is the same - adenovirus. But in pheasants, it occurs with damage to the spleen, in turkeys, hemorrhagic enteritis manifests itself in the form. Use only this vaccine, somewhere around four to six weeks of age. 

Why four to six weeks? Before four, you don’t need the vaccine, the vaccine will not work, maternal immunity will destroy it, after six weeks it is already too late, therefore, at the age of four to six weeks, apply this vaccine. 

I would not use other vaccines. But this does not mean that the turkey does not get sick, it also has respiratory mycoplasmosis, and the turkey is more severely ill with Newcastle disease than the chicken. Therefore, if the region is very unfavorable for Newcastle disease, then both pheasants and turkeys need to be vaccinated with Newcastle disease. 

To summarize: Bronchitis, Newcastle, Gumboro and Marek's disease on chickens, hemorrhagic enteritis on turkeys and hemorrhagic enteritis, or pheasant mottled spleen on pheasants, that will be enough. Pigeons also need to be vaccinated. In many regions of the Russian Federation there are pigeon breeders, this bird often suffers primarily from Newcastle disease. 

- Does the acquired poultry vaccinated with live vaccines (pull hens) pose a threat to unvaccinated poultry of a private farm? What vaccines are needed when vaccinating a broiler turkey, broiler duck? The minimum vaccination complex for broilers is clear: Gamboro, Marek, Newcastle disease, infectious bronchitis of chickens. And for turkey, duck is there a mandatory minimum set? 

- First, I will tell you about the danger of imported vaccinated poultry for the birds that are already on this farm. The danger is not that this bird has been vaccinated, that is, there will be a spread of the vaccine virus. This is not scary, because the vaccine virus, if you brought this bird immediately after vaccination, then the first, on average, five to seven days, the virus is released, no matter what it was vaccinated with: Newcastle, bronchitis, Gumboro or even Marek's disease. There will be such a release and this bird, which is kept in this farm, will receive this vaccine virus. 

There is a big danger if you brought a bird and even vaccinated against Newcastle, Gumboro and bronchitis, but the bird was brought from the farm, and a reovirus infection is blazing there. 

You will bring this pathogen to this farm and there will be a spread not of the vaccine virus with which it was vaccinated, but of the vaccine virus of the contaminant that is in this farm. 

And here in the first place it is necessary to look at the presence of bronchitis, if you have vaccinated the bird with classic bronchitis, and there are variant strains of bronchitis on the farm. Classical bronchitis, the vaccine virus will not protect against the variant. The presence of other contaminants, including leukemia, including mycoplasmosis, poses a risk. Therefore, here it is necessary to look and determine from which farm you are importing, to study its well-being or disadvantage for certain diseases. 

Now about the vaccination schemes for turkeys and ducks, the so-called broilers. For a turkey, hemorrhagic enteritis is in the first place, but if there are a large number of turkeys and if the farm is not from a disadvantaged region, then I would definitely make Newcastle disease as well. 

If there is trouble with the flu and there is a poultry farm nearby where bird flu was blazing, then of course vaccinate this turkey against bird flu. How? The serotype that was. If there was H5, then H5 is needed, if there was H9, then the turkey must be vaccinated with a vaccine from the H9 strain and serotype. If H7 appeared, then it is necessary to vaccinate with the H7 vaccine. 

Now, as for the ducks. Everything is the same, but ducklings have viral hepatitis in the first place. Vaccination against this disease is indispensable. If you still have geese there, then a vaccine against viral enteritis of geese is required. Unfortunately, such vaccines are not produced everywhere in our country, but you can find them.

— Our next question is from manufacturers of drugs for farm animals. This, in particular, Tambey smoke bomb based on fir oil, and feed additive based on essential oils for the prevention of respiratory diseases in cattle, poultry and pigs. How effective is the use of these drugs against topical viruses in industrial-type enterprises: poultry farms, cattle farms, pig breeding complexes? Do you see the point in using these essential oil based formulations in existing vaccination systems during growing season? 

- I am fine with smoke bombs, but first of all, with bombs that are used to prevent parasitic diseases, to prevent external, skin parasites - they have an effect. Regarding the use of smoke bombs for viruses, it is difficult for me to answer. Even if there are essential oils or some drugs that can affect the virus, I have not seen much effectiveness. I find it hard to imagine that a smoke bomb for the prevention of respiratory viruses can help. 

So you sprayed a smoke bomb, the bird breathed, you ventilated this room, and after that your bird will become infected. The smoke bomb no longer works. Even if it works on the virus, you won't be smoking this smoke bomb every day. And the virus is such a parasite, it is necessarily intracellular, if it gets inside the cells of the respiratory tract, even the upper respiratory tract, then the smoke bomb will not help. It will help if the virus has not yet entered the cell. 

If the flu is blazing now and we have this virus floating in the air, then a smoke bomb can kill this virus. But you will not always keep a bird in smoke. In the fight against viral diseases, vaccination comes first, these are live or inactivated vaccines, immunological methods of prevention, that is, the creation of immunity. 

- Question from Sergey Dziub, he is the chief veterinarian, Karaganda. Does 4/91 protect against QX? 

“These are variant strains of infectious bronchitis virus. 4/91 is a vaccine virus, QX is a pathogenic Chinese variant, although it is believed that the QX vaccine has a serotype? I'll tell you this - I don't know. Many scientists say it helps, others say it doesn't. 

My personal practical experience, I was convinced that 4/91 will help in the fight against QX. I know that in Kazakhstan and in Russia this Chinese version is widely circulating. Many manufacturers are starting to call them by their proper names, but I know that there is mainly this variant 4/91 sitting there. Variant 4/91, which was made by Intervet and released as a vaccine, helps against the Chinese version of QX. So if your farm is not QX free, vaccinate 4/91. 

Another question is how to vaccinate? It is necessary that serious veterinarians develop a vaccination scheme. 

There are disputes: is it necessary to vaccinate with a variant strain from the first day or not from the first? Some say: the first vaccine should be classical: A5 or H120. Others say: variants are possible from the first day, others say: mix different viruses, both classic and variant. Fourth say: mix five or six variants of different viruses and vaccinate. 

I am against this method, I believe that it is necessary to vaccinate with one serotype and it is necessary to clearly determine which vaccine to enter first. The classic variants are the first vaccination at day old, with the classic A5 or H120 strain. The second vaccination two weeks later is the variant strain. 

If there is a tense epizootic situation and this variant virus circulates in you, go on the first day, but with one strain, do not mix different strains. I repeat once again - viruses, including bronchitis, are strictly intracellular parasites. And most often it happens like this: the strong virus enters the cell first, most often the classic strain is strong. This means that the place is occupied, two viruses rarely enter the same cell together, and if one virus enters, it closes like a key in a keyhole, the other will not be allowed. Therefore, the approach, if you are very unfavorable, vaccinate according to QX at a daily age of 4/91, and already at the next vaccination, see which one to repeat: variant or make it a classic strain. 

- The next question we have is from Daulet Karzhasov, he is from the Republic of Kazakhstan, the city of Karaganda, a veterinarian. He asks if there are characteristic pat changes in H9 and H5 avian influenza in broilers and parent flocks? 

- The flu generally has characteristic changes. First of all, it is a panthropic virus. This is the strongest hemorrhagic syndrome. You will see hemorrhage in various organs and tissues, and on the mucous membranes, and on the serous membranes. You will see the characteristic Marusin belt - a hemorrhagic belt on the border between the muscular and glandular stomach. You will see these signs when a highly pathogenic H5 virus appears. With low pathogenic H9, you may not see any stalemate or hemorrhage, but the influenza virus will be there. 

Therefore, any organs can be selected to monitor: either the spleen, or Gartner's glands, or even a piece of the liver. The virus can be detected in various organs and tissues. With a low pathogenic strain, often the damage to the organs of egg production is not as severe as with highly pathogenic influenza. With influenza, there are no classic signs of the appearance of a tumor on the liver, as with Marek's disease, damage to the phimus, as in infectious anemia, damage to the bronchi in bronchitis. Influenza is a virus that infects various organs and tissues, including the NERVOUS SYSTEM. 

- What is the development of immunity in broiler chickens after the use of inactivated vaccines against avian influenza, plus Newcastle disease, at the age of one day and at the age of ten days? 

- The inactivated vaccine is made on the basis of an oil emulsion like an inverse emulsion. After vaccination with such a vaccine, immunity will be obtained, on average, after three weeks, sometimes even later. Therefore, if you are vaccinated on the day, do not expect that you already have immunity the next day. 

If there is trouble, then you need to start with the parents, you need to vaccinate the parents with an inactivated vaccine. The first days the chicken lives at the expense of maternal immunity. 

The chicken itself must be vaccinated at day old, not ten days old. Maternal antibodies do not create any danger, they will not interfere, this is an inactivated vaccine. Therefore, in disadvantaged areas, vaccinate parents with an obligatory inactivated vaccine, vaccinate broiler offspring with an inactivated vaccine at a day old and understand that in the first days it is alive due to maternal immunity. 

I advise you to vaccinate broiler chickens with a non-oily, emulsion vaccine, which is made like an inverse emulsion. Vaccinate either sorbed, aluminum hydroxide and immunity will come in two weeks, or oil, but made like a direct emulsion. But still, it should be a sorbed vaccine, aluminum hydroxide. 

And vaccinate with these vaccines at the age of one day, immunity will be developed, regardless of whether there is maternal immunity or not. Therefore, in unfavorable areas, vaccinate parents with an oily emulsion vaccine in the form of an inverse emulsion, and offspring with an adsorbed one.