[The purification of tick-borne encephalitis virus preparations of cellular DNA]

According to the WHO requirements, the concentration of cellular DNA in vaccine preparations produced by pooling virus from continuous cell lines is limited to 100 ng/dose. In this study, different methods were used for purification of tick-borne encephalitis virus suspensions grown in continuous cultures of cell line 4647 from cellular DNA. Two approaches are proposed based on treatment with DNAse and promamin sulfate which allow one to reduce cellular DNA concentration in the virus preparation to the acceptable level. Prospects of their use in vaccine production are discussed.

[The future of vaccines: recombinant DNA vaccines]

Classical approaches to the development of vaccines have provided mankind with a number of safe and effective vaccines (think of the world-wide eradication of smallpox). Nevertheless, some obstacles e.g. the production of a safe Hepatitis B vaccine, could not be taken by classical techniques. In several cases, recombinant-DNA technology provided an elegant solution, though in other cases, this technique also failed. The present paper presents a brief review of the role of recombinant-DNA technology in the current development of vaccines.

[A new rabies vaccine in public health practice in the USSR]

A new antirabies vaccine prepared on the basis of virus grown in the ovine brain, purified from 85-90% of brain-tissue ballast substances and inactivated with beta-propilactone has been developed at the Moscow Research Institute of Viral preparations (USSR Acad. Med. Sci.). The preparation produces no neuro-allergenic effect in tests on guinea pigs. When injected to humans, the vaccine shows much lower reactogenicity than Fermi vaccine. High antigenic and immunogenic activity of the new vaccine has made it possible to work out a less intensive immunization schedule in comparison with that used for immunization with Fermi vaccine and nonconcentrated tissue-culture vaccine, viz. doses of 3 ml for 12 days or doses of 3 ml for 20 days with two booster immunizations. The preparation has been introduced into medical practice.

[Quantitative patterns of the thermal inactivation of microorganisms as a basis for obtaining high-quality vaccinal preparations]

The model of the thermal inactivation of microorganisms is presented. This model permits the explanation of all existing kinetic dependencies relating to the death of microorganisms, the restoration of sublethal damages, the influence of the medium and the temperature of incubation on the process of the production and control of vaccinal preparations.

Clinico-immunologic and allergologic studies with the inactivated influenza virus vaccine purified and concentrated by gradient centrifugation

Vaccination activity and safety of inactivated influenza centrifugal divaccine have been studied in groups of subjects aged 18 to 22, 15 to 16, and 9 to 14 years. The vaccine tested contained either a standard dose (6-8 micrograms) or double a dose (12-16 micrograms) of the haemagglutinin (HA) of influenza viruses A(H1N1) and A(H3N2). The double antigenic load of the vaccine did not enhance its reactogenicity for adults or adolescents aged 15 to 16 years. It enhanced, however, the production of antihaemagglutinine antibodies to the vaccine strains. The range of the antibodies formed and their persistence were independent on the virus dose. The increased dose (12-16 micrograms) of HA decreased the humoral immune response in school children aged from 11 to 14 years. Neither standard nor double dose of the vaccine caused any changes in the biochemical or haematological parameters of blood and urine. No allergic response was registered by the indirect mast cell degranulation (IMCD) test in rats.