Smallpox vaccine

The smallpox vaccine is a live vaccine for the prevention of smallpox. For the production of smallpox vaccine used cowpox virus and ospowiki. The latter is variola virus weakened by multiple passages through the body of cows and other animals, with the result that he has lost the ability to cause smallpox, but when introduced into the body creates immunity to it. For the production of smallpox vaccine use of cows, calves, sheep, sometimes Buffalo, rabbits and chicken embryos and tissue culture. Animals vybivaet the skin and make a lot of small incisions, rubbing vaccinia virus or vaccinia virus. In 4-5 days, when the formation pox blisters are slaughtered, the skin is treated with phenol, wash water and scraped pockmarks. Suspension crushed the scraping winced smallpox called detritus. Smallpox vaccine can be liquid (when pox plant detritus 4-5 times glycerin) or dry (when the detritus add 10% protein filler and then poured into capsules and put the vacuum drying). Sealed vial of the dry smallpox vaccine when stored in the refrigerator (temperature of 2 - 4 degrees) keeps its activity not less than 12 months, while liquid vaccine - not more than 3 months. In the USSR mainly cooked dry smallpox vaccine. Before opepreveria (see) dry smallpox vaccine plant with glycerine, which is usually attached to each ampoule of smallpox vaccine.

Smallpox vaccine (vaccinum variolae) - live vaccine for the prevention of smallpox, in production of which is used as a cowpox virus and ospowiki (vaccines), related antigenically to the variola virus.
The cowpox virus is the causative agent of smallpox cows, a characteristic symptom of which is the formation of the udder of cows bubbles containing the virus. Contracted the virus while milking the sick smallpox cows, a person becomes immune to smallpox.
The origin of vaccinia virus is not clear enough. It is considered as the variola virus that has changed under the influence of passages through the organism cows or other animals and lost the ability to cause smallpox in humans, but kept immunizing ability. Almost vaccinia virus identified with cowpox virus, because the differences between them are revealed only in special research methods.
Vaccinia virus was first used to prevent smallpox Jenner (E. Jenner, 1796). The smallpox vaccine is prepared either in liquid form (mixture pox material with glycerin), either in the form of dry vaccine before use, mix with glycerin. For the production of smallpox vaccine can be used by various animals (cows, calves, sheep, rarely Buffalo, rabbits), chicken embryo and tissue culture (see). O. century, obtained by cutaneous infections of animals, called the dermal, unlike smallpox of ovomaltine preparing on chicken embryos, and tissue O. century, prepared with the use of tissue culture in vitro. As industrial strains used cowpox virus or ospowiki. Cultures must be genetically uniform, immunogenic enough and can cause benign raised bumps on the skin grafted people, rabbits and the chorion-allantoina shell chick embryos.
To obtain dermal smallpox vaccine in the USSR use of cows and calves, rarely Asses. After vybivanija the abdomen infect animals in skalpirovaniya skin vaccine strain, carefully wiping the grafting material in the skin incisions. 4-5 days in the period of maximum concentration of the virus in developed winced animals are killed. The removed skin is treated with phenol, wash water and scraped pockmarks. Scraping thoroughly crushed and get the smallest suspended - pox detritus. For the manufacture of liquid drug detritus bred glycerin, so that the final product is a mixture of 1 teaspoon of detritus from 4-5 p.m. 40-80% of glycerin. For the manufacture of dry dermal pox vaccine for smallpox detritus add filler is a mixture of chicken protein with sucrose, less 10% a solution of gelatin or horse serum. Ospen detritus filled with bottled in capsules, dried, frozen under vacuum (see Lyophilization) and sealed. Dry O. century is more resistant to high temperatures and during storage in the cold remains active for at least 12 months. With the same conditions of liquid vaccine suitable not more than 3 months. Therefore, in the USSR made only dry dermal O. C.
After repeated passages from one calf another vaccine strain may weaken. Virulent properties restore, pursuing a strain through susceptible organism of a different species. In the USSR are using two methods of preservation of vaccine strains: passages calf-rabbit-calf and the calf-ass-calf. Grafting material, obtained by passage through the body of a rabbit called Lapina through the body of the donkey - asinine, through the human body - retroactively.
Ospen ovulatino prepared by infecting 12-day-old chick embryos in allantoina cavity virus dermolectine. After 72 hours after infection Rorion-allantoin the shell remove, thoroughly homogenized and mixed with stabilizer (10% of gelatin, 50% or chicken protein milk).
Tissue smallpox vaccine receive contamination of cultures of tissues of organs and embryos of healthy animals. The culture fluid collected in the period of complete degeneration of the infected cells and mixed with a filler (5% peptone or a mixture of egg yolk with sucrose). Ovomaltine and tissue vaccine produced in a dry kind.
Quality assessment O. C. conduct by defining bacterial pollution, safety, immunogenicity and thermal stability. O. B. must be completely free from pathogenic bacteria, which establish, infecting it mice or Guinea pigs. In the dermal O. century Pets presence of non-pathogenic to humans microbes, but they should make no more than 1000 colonies at sowing 1 ml of the vaccine. To suppress microflora use of antibiotics in minimum quantities.
The specific activity of the ready O. C. check on rabbits (method Grotto) and Guinea pigs (method of Ginza). When assessing the activity according to the first method rabbits intradermally injected trial medication in different dilutions. The vaccine is considered safe, if after 96 hours. the sum of cross-sections infiltrates, formed on the ground of vaccine administration, at least 30-35 mm In determining the activity according to the method of Ginza infect pigs (skalpirovaniya cornea) of different concentrations of grafting material. The vaccine causes in breeding 1 : 10 000 and above expressed keratitis, suitable for consumption. One way to check the smallpox vaccine is also a primary vaccination of children. O. century is considered safe if it gives not less than 90% of positive responses on the number of children and 70% of success by the number of vaccinated cuts.
In addition to these methods, the who recommends to determine the activity O. C. infection of rabbits on skalpirovaniya the skin and chick embryos on the chorion-allantoin shell. O. century is considered suitable when applied to skalpirovaniya skin rabbit in dilution up to 1:10 000 calls through 4-7 days is typical single pox vesicles, and in a dilution of 1 :1000 - drain destruction. Definition of activity on chicken embryos is to infection 12-day-old embryos on the chorion-allantoin shell.
Thermostability of dried smallpox vaccines determine keeping dry drugs at 37 degrees and in a period of 4 weeks; after this period, O. B. must meet the requirements specified above.
In the USSR for the prevention of smallpox used mainly dermal O. century, the most tried and tested practice. In the USA, Switzerland, along with dermolectine used ovomaltine. Tissue O. C. apply in Sweden, the Netherlands and Mexico.