[Immunogenicity and stability of a Soviet inactivated cultured vaccine against Japanese encephalitis].

Six immunologically active vaccine batches inducing a specific antibody to Japanese encephalitis (JE) virus were obtained in serial manufacture of the preparation. In HI tests, the minimal antibody titre was 1:80, the maximal 1:320, neutralization index 1g was 3.7 to 5.

[RAMT cell line as a substrate for the propagation of vaccinal viral strains].

Properties of the PAMT cell line which are deficient in hypoxanthine guanyl phosphoribosiltransferase were studied. The PAMT cell line derived from African green monkey kidney tissue may be identified by selective nutrient media, contains no contaminants, is not tumorigenic, is susceptible to a wide range of viruses. Titres of poliomyelitis, tick-borne encephalitis, and carnivore plague viruses were similar in cell cultures grown in the medium with 10% serum and in those adapted to growth in the medium containing 1% serum.

Comparative study of infectious and formaldehyde-inactivated tick-borne encephalitis virus particles.

The structure and properties of infectious and formaldehyde-treated particles of tick-borne encephalitis virus, concentrated and purified by chromatography on macroporous glass, were studied. In addition to complete virions, such preparations contain some incomplete forms that differ in density, morphology and protein composition (incomplete forms do not contain nucleocapsid protein). The physico-chemical analysis of complete virions showed that formaldehyde treatment causes a) the formation of glycoprotein dimers and b) a portion of nucleocapsid protein to become tightly cross-linked with viral RNA.

[Comparison of methods for the large-scale culture of cells and viruses].

The paper presents the results of experiments on propagation of primary, secondary, and continuous diploid and heteroploid human and animal cells in 2 different systems for large-scale propagation: in perfusion tank with Rashig rings and in tanks with microcarriers. Both methods of large-scale cultivation produce higher cell yields than the traditional cultivation methods. A yield of tick-borne encephalitis virus per 1 cell in the perfusion cultivator was 12 times as high as in roller cultures.