The immune system is a network of cells and organs that work together to protect the body from harmful objects. The immune system also responds to vaccines by using methods used to fight pathogens. To prevent the disease, vaccination should usually be done before exposure to the pathogen. Vaccination is the creation of artificial and specific immunity to a particular infectious disease, which significantly reduces the symptoms and death of the disease. After receiving the vaccine, the immune system begins to respond so that it can be able to destroy if it encounters a pathogen. Vaccines should be free of any bacterial or fungal contamination so that they don’t cause secondary microbial contamination if used. Therefore, sterile test is necessary to detect microbial contamination in the vaccine. In order to perform the sterility test, the nutrient and culture media of bacteria and fungi are used as agar plates or broth environments. The environments used must be able to grow different microorganisms and also be free of any contamination. All the raw materials used in vaccine production are examined during the process of analyzing the raw materials in terms of microbial contamination. To ensure sterility and non-contamination, all stages of vaccine production, including maternal seed, seeding, cell passage, virus-to-cell inoculation, intermediate bulk production, final bulk production, and final product, are evaluated. Dedicated culture media such as tryptic soy broth (TSB) and Fluid thiogllycolate media (FTM) culture media and agar culture media such as Blood Agar, TSA and SDA are used in each sterility test. TSB and Agar cultivation medium is prepared in sterile conditions and Growth promotion test is performed according to EUROPEAN PHARMACOPOEIA 8.0 reference for each series of cultivated medium. Negative control of TSB for 14 days and agar environments for 5 days are kept in incubator at 37˚C. They are used in the sterility test after performing a Growth Promotion test and ensuring that the environment is sterile. The TSB culture medium and the FTM culture medium, which are specific to anaerobic bacteria, are stored at 2.5 ±32.5˚C and 2.5 ±22.5˚C for 14 days after inoculation. Blood Agar nutrient medium is used for rapid detection of any contamination. SDA environment is also a specific environment for fungi and yeast and together with TSA environment, they are kept at 2.5 ±22.5˚C for 5 days and microbial growth will be considered every day.
One of the most serious and important problems related to cell culture is the contamination of culture media with different species of mycoplasma bacteria. Infection of cell cultures with mycoplasma causes changes in cell growth, morphology, metabolism of amino acids and nucleic acids, and of course affects the biological products produced in cell cultures, which can lead to errors in the interpretation and analysis of test results and thus gain unreliable results. Infection of cell cultures with mycoplasmas is a problem seen in most cell culture laboratories. Contamination may remain unknown for a long time, affecting cell proliferation, gene expression, and other cell responses. Types of mycoplasmas found frequently in cell cultures include: Mycoplasma arginine, Acholeplasma laidlawii, Hyorhinis Mycoplasma, Mycoplasma orale, Mycoplasma fermentans and Mycoplasma hominis. these species are 95% cause of cell culture contamination. The most common methods of detecting mycoplasma contamination are microbial culture, biochemical tests, immunofluorescence, and nucleic acid-based methods. Direct microbial culture, biochemical tests, and immunofluorescence are time-consuming and costly methods that are not cost-effective for researchers. However, polymerase chain reaction is a very sensitive method and a good technique for diagnosing mycoplasma in Cell culture. Comparison of polymerase chain reaction (PCR) method with other methods shows that PCR is a fast with high accuracy and specificity and more cost-effective than other tests in order to identify different species of mycoplasma. Vira vaccine Company, with its modern equipment in the field of molecular tests, as well as specific sections of PCR, Pre PCR and Post PCR, has been able to identify different types of mycoplasmas with high precision and sensitivity in cell culture, cell and pharmaceutical products using special primers.
The virus in Latin means stubborn, poisonous, foul-smelling, ugly, and generally an undesirable thing. Humans or other animals have the same way of causing disease. Viruses do not have cellular structure and behave like living compounds outside of living cells, and in fact do not have the ability to reproduce. Viruses are inactive in the extracellular environment and only reproduce in living cells, that is, they are genetically parasitic. CPE is the morphological changes that can be seen in virus-infected cells. Viruses are divided into two groups according to the effect they have on the host cell:
In order to see the effects of a virus on a cell, two factors are needed: 1. The virus is cytopathic, 2. The cell is sensitive. Viruses that have the ability to cause cytopathic effects can be evaluated if the virus is inoculated in a sensitive cell. Virus grade determination test is a semi-quantitative method that is reported based on TCID50. TCID50 shows how much of the pathogen can cause cytopathic changes in 50% of cultured cells. Determining the virus grade is done in two ways, micro and macro. In the titration test, consecutive dilutions are prepared based on a specific number of viruses and are exposed to the sensitive cell, kept at 37˚ C for 8 to 10 days, and tested daily for CPE. At the end of the virus incubation, titration is calculated by using the Reed & Muench method or the Karber method.
Each vaccine must be evaluated for clinical and non-clinical symptoms in the target animal and laboratory case. The safety test is divided into two categories: 1) Harmlessness in the laboratory animal and 2) harmlessness in the target animal. In order to study the clinical effects of the vaccine on the target animal, the highest dose of the vaccine is injected into the target animal. The purpose of this test is to investigate the effects of the vaccine when receiving the maximum dose of the vaccine. After the maximum dose is injected, the organism is checked for health at regular intervals. Failure to observe any severe or long-term clinical symptoms indicates the safety of the vaccine, whereas if the clinical symptoms of the disease are less severe and the patient recovers more quickly, the vaccine is safe to pass. Laboratory animals such as mice, hamsters, guinea pigs, rabbits, etc. are used for harmless vaccine studies. Since the 19th century, the use of laboratory animals in scientific studies has become popular due to their small size, high reproductive capacity, variety of species, easy access, less space required and their systemic resemblance to the target animal. In each clinical study, several factors are effective in choosing the type of laboratory animal used. Factors such as:
Animals such as mice and guinea pigs are more commonly used in risk-free studies due to their small size, ease of operation, and affordability. Laboratory animals are monitored for temperature, weight, clinical and non-clinical symptoms after receiving the vaccine. At the end of the test period, the animal is checked and any bleeding in the digestive system, circulatory system, respiratory system, and genitourinary system can indicate that the vaccine is not harmless. If any laboratory animals die, the causes of the animal's death should be investigated and the test repeated if necessary.
In order to evaluate the efficacy of the vaccine produced, an Efficacy test is performed. Vaccine efficacy assessment has the advantage that the exact immunogenicity of the vaccine and the dose of the vaccine can be obtained. For this purpose, the lowest dose of the vaccine is injected into the target animal, and by measuring the amount of antibody produced by the vaccine in the animal's body by serological methods, the vaccine can be safely tested at least in the injected dose. To perform this test, it is necessary to vaccinate a specific number of target animals with the minimum dose according to the standards of reputable authorities (for OIE livestock vaccines) and after a certain period of time to evaluate the effectiveness. He got vaccinated. If, under certain conditions, the available dose is less than the required dose, the herd can be vaccinated according to the knowledge of the vaccine's effectiveness and ensure that the herd is safe. To perform this test and ensure its results, target animals that are undergoing clinical trials must not have previously had any immunity to the disease. That is, they have not been vaccinated, nor have they contracted any similar diseases, because in this case, the animal has an antibody titer and the test results are unreliable. For this purpose, before performing the efficiency test, the animals in question are given blood samples and antibody measurements are performed.
the link between test effectiveness and clinical efficacy is the basis for vaccine use. The old way to check potency is the challenge method. After vaccination, the same animal is infected with the pathogen and the animal is clinically examined for two weeks. If the animal is resistant to the pathogenic strain and shows no clinical signs, the animal is resistant to the pathogen and the potency test has been successful. In newer methods, antibody titer testing (serology) is used to evaluate the potency of livestock vaccines. In this method, the effect of the vaccine is assessed by identifying the level of antibody titer after vaccination using the Enzyme-linked immunosorbent assay (ELISA) method. At Vira vaccine Shaya, the effectiveness of livestock vaccines is measured with great precision, with the help of experienced personnel and the use of antibody measurement kits from reputable global companies.
The Vira Vaccine Shaya Company was established in 2018 by the Specialists in the pharmaceutical industry. This company is active in the field of production, distribution, sale, import, and export of various drugs and serums, human vaccines, livestock vaccines, biological products, advanced and high-tech industries.
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