Historical analysis of epizootiological situation of rabies on the territory of the Slovak Republic.

Currently, Slovakia is a rabies-free country, but the epizootiological situation of rabies was not always favorable. The main reservoir species of rabies virus in the first half of the last century was the domestic dog. Since 1906, hundreds of cases were reported, of which approximately 90% were infected dogs.

Experimental squalene adjuvant. II. Harmlessness and local reactogenity.

Model experiments on laboratory animals (guinea pigs) were carried out to test the possible allergic reaction (possibility of sensitisation) to the repeated administration of an experimental lipoid adjuvant prepared on the basis of squalene (experimental squalene adjuvant--ESA). No significant differences were observed between the animals sensitised-provoked with ESA and control animals. In order to evaluate the local tissue reactivity (local reactogenity), also with regard to the process dynamics to the administration of ESA, comparative patho-anatomical and patho-histological examinations of tissues were carried out in the location of adjuvant administration.

Experimental squalene adjuvant. I. Preparation and testing of its effectiveness.

The authors prepared experimental lipoid adjuvant of the oil-in-water (O/W) type, based on squalene (ESA: experimental squalene adjuvant), intended for liquid inactivated veterinary vaccines. The final concentration of squalene in the vaccine was 5% (w/v). Detergents Poloxamer 105 in the concentration of 4% (w/v) and Abil-Care in the concentration of 2% were used as emulsifiers.

[Correction of measurement errors in the ELISA test].

The authors followed the influence of the arrangement of measured and control samples on microtitration plate on the ELISA test results by quantitative evaluation of rabies antibodies titres in human blood serum. They performed the test under identical conditions in all microtitration plate wells. They calculated the result according to five calibration curves--four of them were obtained by different positioning of the control positive and negative sera and the fifth curve was obtained from average values.

[Isolation and identification of Lyssavirus strains from an area of Slovakia where oral antirabies vaccine was administered].

The study was aimed at isolation and subsequent identification of strains of rabies virus by means of monoclonal antibodies from foxes killed in the vaccination zone within the complex preliminary monitoring of oral antirabies vaccination. The results obtained indicate that the vaccines for oral antirabies vaccination used in Slovakia did not contain any vaccination strain pathogenic to the extremely sensitive target species-the fox (Vulpes vulpes).

The effectiveness of inactivated, purified and concentrated experimental rabies vaccine for veterinary use: immunogenic activity.

The authors prepared an experimental, inactivated, concentrated and highly purified rabies vaccine from the strain Vnukovo-32/107. The purification and concentration (simultaneous--in one operation) was carried out by affinity chromatography. The content of rabies antigen in the vaccine was 4.

The immunomodulatory effect of the soluble fungal glucan (Pleurotus ostreatus) on delayed hypersensitivity and phagocytic ability of blood leucocytes in mice.

The effect of fungal and yeast glucan on different immune functions in mice was examined and compared. The simultaneous administration of glucan and a sensitizing dose of DNFB on the different sites significantly stimulated delayed-type hypersensitivity (DTH) response only when using fungal glucan. Both glucans tested, when administered before sensitization, significantly increased DTH response, but with a significantly higher level at the beginning of the investigation (on day 7) when using fungal glucan.

Immunogenic and antigenic activity of an experimental oral rabies vaccine prepared from the strain Vnukovo-32/107.

The immunogenic and antigenic activity of an experimental live oral rabies vaccine prepared from the strain Vnukovo-32/107 was evaluated on the basis of results obtained in 3 sets of experiments. These were carried out as model experiments on white mice, then on target animals--red foxes (Vulpes vulpes) and a related species--farm-bred polar foxes (Alopex lagopus). For quantitative determination of the immunogenic activity of the orally or subcutaneously administered rabies vaccines in model experiments on mice a method was used that had been developed in our laboratory.

Quantification of residual virulence of the Vnukovo-32/107 rabies virus vaccination strain.

The present work summarizes the results of 11 groups of experiments carried out with the aim to complexly quantify the residual virulence of a cold mutant of the Vnukovo-32/107 rabies virus vaccination strain intended for the preparation of an oral rabies vaccine (Kamark) for the immunization of free-living carnivores. According to WHO prescriptions, residual virulence was quantified in experiments on carnivores, mainly red foxes (Vulpes vulpes)--the presumed target species, and farm-bred polar foxes (Alopex lagopus)--a related species. Further experiments were carried out in cats, dogs, non-target autochthonous micromammals, predatory birds (Microtus arvalis, Apodemus flavicollis, Falco tinnunculus) and in a large number of laboratory animals--white mice.

[Quantification of levels of serum antirabies antibodies in vaccinated individuals].

The authors developed a kit for the purpose of assessment of anti-rabies antibodies by the ELISA immunoenzymatic method in human immunized sera. The results of the detection and quantification of anti-rabies antibodies acquired by the ELISA method were compared with those originating from classical procedures (virusneutralizing test on mice, indirect hemagglutination test), and a sufficient correlation and sensitivity of the immunoenzymatic method were detected. By means of the developed test it is possible to detect the particular level of anti-rabies virusneutralizing IgG antibodies.

[The effect of fungal and yeast glucan and levamisole on the level of the cellular immune response in vivo and leukocyte phagocytic activity in mice].

The level of cell-mediated immune response in vivo was investigated using the test of delayed hypersensitive reaction (DHR) to DNFB, along with the phagocytic activity (PA) of blood leucocytes in mice after subcutaneous implantation of fungal and yeast glucan and levamisol in dependence on the dose and administration schedule. The soluble form of fungal glucan (Pleurotus ostreatus) potentiated the DHR significantly at a dose of 10 mg/kg (but not at a dose of 50 mg/kg) while it was administered during DNFB sensitization (P < 0.05)-Tab.

[Use of the skin test in the evaluation of true levels of cellular immunity and levels after experimental administration of glucan and levamisole in feed-lot bulls].

Applicability of a skin test induced by dinitrofluorobenzene (DNFB) to quantification of the actual level of cellular immunity (CI) in vivo and its level after an experimental immunomodulation intervention were evaluated in two breeds (40 animals in each) of fattening bulls (10-11 months old). At the selected methodical procedure of intensity determination of the delayed type of hypersensitivity (DTH), its average value reached 4.5 +/- 1.

[The effect of adjuvant substances on the antigenic activity of cellular antirabies vaccine in experiments on cattle].

Trials were conducted with young cattle to study the effect of adjuvants, applied subcutaneously and intramuscularly, upon the antigenic activity of live and inactivated cell rabies vaccine prepared from the Vnukovo -32 strain at the level of the 107th series cell passage. Cerebral vaccine of Fermi type was also used in the trials for comparison. The antibodies were parallelly titrated by four methods, three of which were conducted in vitro.

[Distribution of rabies antigen in the central nervous system of rats and mice experimentally infected with rabies strains isolated from hamsters (Cricetus cricetus)].

The comparative experiments were carried out to study the distribution of the rabies antigen in the central nervous system (CNS) of sewer-rats and mice experimentally infected with three "hamster" strains (for comparison also with "fox" strain 1151); it was found out that with microscopical observation of preparations stained by the method of direct immunofluorescence the "hamster" strains produced a blended picture of fluorescing particles characteristic of strains with a reduced virulence and virulent strains. As for mice infected with strains 3 O and 7 E the rabies antigen was detected in all parts of CNS as early as 24 hours after infection. In this period the rabies antigen strain 9 E was not detected in lumbar spinal cord and that with strain 1151 was detected only in the Ammonian horns.

[Pathogenesis of experimental rabies infection in foxes and cats infected with viruses isolated from hamsters (Cricetus cricetus)].

All the infected foxes (9) contracted the disease and died from rabies the 20th-21st day from infection with the virus isolated from hamster. Out of the total number of 9 cats experimentally infected by intramuscular infection, seven showed symptoms of clinical disease on the 18th-34th day from infection. The infected dogs, wolves and rabbits did not show clinical disease.