RU1822792C - Vaccine against infection bronchitis in chickens - Google Patents

Abstract

Usage: veterinarians, biotechnologists, virologists. Based on available domestic raw materials, an effective vaccine virus against chicken infectious bronchitis was obtained. The vaccine virus against chicken infectious bronchitis is prepared from an attenuated domestic strain AM, which is deposited in the collection of VGNKI at number 65. The vaccine contains peptone, gelatin and sucrose. 2 tab.

Description

The invention relates to veterinary virology, and in particular to methods for producing live attenuated vaccines, in particular against chicken infectious bronchitis.

The aim of the invention is to obtain, on the basis of available domestic raw materials (embryos from infectious diseases-friendly breeding poultry farms) an effective vaccine virus against chicken infectious bronchitis, more immunized and with a wider antigenic spectrum, which provides reliable protection against the virulent virus infectious bronchitis of various serotypes.

The goal is achieved in that a vaccine virus against chicken infectious bronchitis is prepared from an attenuated domestic strain of AM.

To prepare the vaccine, embryos of 9-day incubation from SPF-farms or farms that are successful in infectious diseases of birds are infected with the vaccine strain AM virus in the allantoic cavity

Infectious bronchitis of chickens in a volume of 0.2 ml. Infected embryos are incubated at 37.0 ± 0.5 ° C for 72 hours. Embryos that die within 24 hours after infection are removed and disposed of. The remaining embryos are examined every 12 hours. Dead embryos are removed from the incubator and placed in a household refrigerator at 2-4 ° C. 72 hours after infection, all living and dead embryos are collected, cooled and used to collect extraembryonic fluid. Then it is checked for sterility, the absence of contamination with mycoplasmas and extraneous viruses, biological activity and immunogenicity. The virus-containing fluid must be sterile, not contaminated with mycoplasmas and extraneous viruses. The biological activity of the virus-containing fluid should be at least 6.5 per 1 ml. Subsequently, the virus-containing liquid is mixed with a filler (protective medium containing peptone, gelatin and

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sucrose) in a 1: 1 ratio, packaged in 2.0 ml ampoules or 5.0 ml penicillin vials and lyophilized.

The finished dry virus vaccine is tested for sterility, mycoplasma and extraneous virus contamination, biological activity, safety and immunogenicity.

The vaccine must be sterile, not contaminated with mycoplasmas, viruses, harmless and have a biological activity of at least 1055 EID in 1 ml;

The immunogenicity of the vaccine is tested on 15-20 day old SPF chickens. A vaccine is considered immunogenic if, after infection with a virulent virus, all vaccinated chickens remain healthy without showing clinical signs of respiratory damage. Mild rhinitis in 2 out of 10 infected chickens is allowed.

The chicken infectious bronchitis vaccine virus from strain AM is used to vaccinate chickens and adult birds by feeding, intranasally, and coarse aerosol.

In chickens, immunity occurs 21 days after vaccination and lasts for 3 months. In chickens revaccinated at 90-100 days of age and older, as well as in adult chickens, immunity is maintained until the end of the exploitation period.

The chicken infectious bronchitis vaccine virus from strain AM was tested under experimental conditions on 2887 chickens of 10-15 days old at multiple repetitions and under production conditions on 8 million birds of different ages. In addition, the vaccine was tested twice under production conditions by the state commission in comparison with the foreign virus vaccine from strain H-120. In the first commissioning experiment at the Druzhba poultry farm in the Brest region, 43528 chickens of 9–10 days old placed in two houses were vaccinated with the domestic virus vaccine from strain AM. 43575 chickens of the same age and placed in two of the same houses were vaccinated with a foreign virus vaccine from strain N-120. In one house, 21,764 unvaccinated chickens were left as controls.

It should be noted that when vaccinating chickens with a virus vaccine from strain AM,

1905 of the EIDzo virus were consumed per vaccinated chicken, and the virus vaccine from strain H-120 -5636 EIDzd, i.e. 2.9 times more. The vaccinated chickens were clinically monitored, autopsy of dead birds was carried out, and economic indicators were taken into account. 21 days after re-vaccination, the strength of the immune system was determined by infection with a domestic virulent strain of the chicken infectious bronchitis virus (Chapaevsky strain).

Examples of specific application.

From the table. It can be seen from Fig. 1 that, in a chicken farm that is unsuccessful for infectious bronchitis, vaccinated with a domestic virus vaccine from strain AM grew better and developed. On average, in this group, a gain in body weight per chicken was 49 g more than in the control group, and 62 g more than in the group of chickens vaccinated with a foreign virus vaccine from strain H-120.

To determine the strength of the immune system, 20 chickens were taken from each house and the Chapaevsky strain was infected with the virulent infectious bronchitis virus. The results of the challenge are shown in Table. 2.

From the table. Figure 2 shows that chickens immunized with a domestic virus vaccine from strain AM were resistant to infection with a virulent virus in 60 and 70% of cases, i.e. they had the same resistance as those naturally ill with infectious bronchitis.

Chickens vaccinated with a foreign Dutch vaccine from strain H-120 were resistant only in 25% of cases of the number of infected.

In addition, over the period of the experiment, the average weight gain of each chicken vaccinated with a domestic virus vaccine from strain AM was 34 g more than in the control group, and 11 g more than that vaccinated with a foreign virus vaccine from strain H- 120.

Claims (1)

The formula of the invention A vaccine against infectious bronchitis of chickens, containing a strain of Coronavlrus and a protective medium consisting of peptone, gelatin and sucrose, characterized in that, with the aim of increasing immunogenicity, it contains Coronavlrus VGNKI No. 65 with a titer of 106-107 AID so / ml in equal proportion to the protective medium. Table 1 Economic indicators for groups of vaccinated and control chickens at the Druzhba poultry farm in the Brest region Table 2 The results of the control of infection with a virulent virus of infectious bronchitis