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Fifteen vaccinia virus (VV) recombinants derived from VV strains Praha, LIVP and DD (i.e. Dryvax Wyeth vaccine-derived) and expressing genes for S, preS2-S or c antigens of hepatitis B virus (HBV) were tested in monkey CV-1 cells and human diploid LEP cells. The production of infectious virus was found to be alike in all the recombinants and parental viruses as well. However, several recombinants produced markedly lesser amounts of S and preS2 antigens in LEP cells than in CV-1 cells. This reduction was independent of the parental virus used. There was, however, a relationship between the production of preS2 in CV-1 cells and the production of S and preS2 antigens in LEP cells; in general, recombinants efficiently inducing preS2 antigen formation in CV-1 cells produced markedly reduced amounts of S and preS2 antigens in LEP cells. Reduction of HBV antigen production in LEP cells was not apparent in recombinants expressing only S or c antigens of HBV, and the production of c antigen by double recombinants was not influenced by simultaneous expression of preS2 and S. The various recombinants also differed in the ratio of S:preS2 antigen formation. This difference seemed to be associated with the length of the untranslated leader sequence preceding preS2 but not with the parental virus or cell type used. The titers of antibodies against S and preS2 antigens induced in mice immunized with different recombinants differed markedly. The differences in the ratio of S:preS2 antigen production in vitro were not reflected in vivo by S:preS2 antibody ratio.

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The entire amino acid sequence of human cytomegalo-virus (HCMV) 150K matrix phosphoprotein (pp150), consisting of 1048 amino acid residues, was divided into 95 overlapping 20 amino acid peptides which were synthesized on polyethylene rods. The rods were subjected to ELISA with pooled anti-HCMV-positive and anti-HCMV-negative sera. Four peptides recognized by the anti-HCMV-positive pool only were synthesized by the solid-phase method and their reactivity in a conventional ELISA, using a panel of 14 individual anti-HCMV-negative and 20 anti-HCMV-positive antisera, was evaluated; three peptides were found to be specifically reactive. Results obtained with one of these peptides (residues 595 to 614) in ELISA showed a good correlation with those obtained using a routinely performed complement fixation test.

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Five different recombinant vaccinia viruses expressing the envelope antigen of hepatitis B virus (HBsAg) under the control of the P7.5 promoter were constructed. Cell cultures infected with some of the recombinant viruses synthesized both middle (M) and major surface (S) protein of HBsAg. It was shown that the length of the nontranslated sequence preceding preS2-ATG influenced the extracellular or intracellular HBV antigen distribution and the preS2:S antigen ratio. Some recombinants synthesized an M protein that was enlarged by additional 35 amino acids of preS1 domain and was entirely retained within the infected cells. Antibody responses to the S and preS2 antigens in mice revealed significant differences in the immunogenicity of individual recombinants.

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In a group of 144 children (six months to 15 years) three doses vaccine were administered. The latter contains the main strains of the influenza type A and strain type B. From the clinical evaluation ensued that this vaccine in children is areactogenic even after repeated doses. The morbidity was followed up for 18 months and during this period in the immunized communities no case of influenza was recorded. The antibody levels were assessed by the haemagglutination-inhibition test (HIT) and the enzyme test (NIT) The assessed HI titres were high after the second and third dose, in particular as regard subtype H3N2 and H1N1. The titres against subtype H2N2 and type B were markedly lower. Antibodies against neuraminidase were highest against subtype N1 and type B, lowest against N2. The dynamics of the formation of antineuraminidase antibodies was similar as that of haemagglutination-inhibition antibodies. Based on these results the vaccine is evaluated as very satisfactory and after approval by the Ministry of Health and Social Affairs this vaccine will be used for a field trial in 1-2 thousand children where above all the protective effect of the vaccine will be investigated. This vaccine is intended for children, with the aim to induce complex immunity against influenza.

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Several vaccinia virus recombinants inducing the synthesis of the middle surface (M) protein of hepatitis B virus (HBV) were constructed. One of them, denoted v137, was examined in some detail. The virus replicated nearly to the same extent in various cell lines, viz. human embryo diploid fibroblast LEP and MRC-5 cells, rabbit embryo fibroblast REF cells, TK- rat RAT-2 cells, and green monkey CV-1 cells. However, the production of M protein was found considerably lower in the human LEP and MRC-5 than in the other cells examined. In addition, the kinetics of M formation were different in these two cell systems, LEP cells lagging significantly behind CV-1 cells. The low-level production of M protein in LEP cells was not increased by repeated v137 passages in LEP cells, nor by a passage in a laboratory worker accidentally infected with the v137 virus, nor by shortening the leader sequence preceding the translation initiation codon. The greater part of the M antigen was found to be cell associated, more so in the cells of human than monkey origin. From the major HBV S antigen (HBsAg) isolated from the plasma of chronically infected subjects, the antigen released by cell destruction differed by binding to polymerized human albumin. This property was utilized in ELISA to detect anti-preS2 antibody. Rabbits inoculated intradermally with the v137 virus developed antibodies reactive in this assay as well as with a synthetic peptide corresponding in the amino acids 14-34 of the NH2 terminus of the HBsAg preS2 region.

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Recombinant vaccinia virus expressing the middle hepatitis B virus surface antigen was incapable of inducing marked antibody response against the S and pre-S2 antigenic specifities in mice. However, mice immunized with this virus produced antibodies to both these antigens after the following administration of subtreshold doses of plasmatic hepatitis B surface antigen.

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Rabbits were immunized with a synthetic octadecapeptide corresponding to the sequence ser-91 to leu-108 of the haemagglutinin heavy chain of H3N2 influenza A viruses. They developed antibodies reactive in solid-phase radioimmunoassay (SPRIA) with the peptide and with haemagglutinins of various H3N2 viruses but not of heterotypic H1N1 and H2N2 viruses. The antibodies were also non-reactive in the haemagglutination-inhibition or neutralization test. Influenza H3N2 virus replicated in the lungs of mice immunized with the peptide to the same extent as in the control mice. Of 27 human sera possessing anti-H3N2 activity or seven sera from rabbits immunized with either virions or haemagglutinins of various influenza A viruses, none was reactive with the peptide in SPRIA.

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To determine the risk associated with previous herpes simplex type-2 (HSV-2) infection and possibly other virus infections, a prospective study of cervical neoplasia in more than 10,000 women was performed in the 1975-1983 period. The subjects were selected at random from an alphabetical listing of eligible women living in one district of Prague. At enrollment colposcopy and cervical cytology were performed, a blood sample was taken and data regarding education, socio-economic status, personal habits and sexual and reproduction-associated attributes were obtained from each woman. A total of 10,683 women were enrolled; a complete set of data was obtained in 10,389 women. Women with normal or non-significant findings were invited for further colposcopical and cytological investigations after 2 years and 4 years, the other women were followed at 3- to 6-monthly intervals. In women with highly significant findings, histological investigation was performed. The total of 150 cases of moderate to severe dysplasia (i.e. cervical intraepithelial neoplasia, grade II, CIN II), 83 cases of carcinoma in situ (CIN III) and 21 cases of invasive carcinoma (INCA) were detected. More than 60% of the patients were ill at enrollment, the other cases developed in subjects with originally slightly suspicious (27 CIN II, 17 CIN III, 3 INCA) or negative findings (30 CIN II, 12 CIN III, 3 INCA). Analysis of the data indicated significantly positive correlation of one or more of these clinical conditions with a number of sexual and reproduction-related attributes of which early age at first intercourse was most consistent. Among the other attributes, the smoking habit was associated with the highest risk of developing the disease. A negative correlation of cervical neoplasia with several attributes was demonstrated; of these diathermoelectrocoagulation of the ectopic epithelium and transformation zone of cervix was the most important single protective factor. On the basis of these findings, control subjects were selected for serological studies.

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In search for optimal conditions of influenza virus A/Brazil/78(H1N1) disruption by diethylether-Tween 80 and tri-n-butyl phosphate (TNBP)-Tween 80 mixtures, the following treatments were found suitable: for 120 min at 4 degrees C with 3.3% TNBP and 0.1% Tween 80 or for 120 min at 4 degrees C with diethylether and 0.1% Tween 80 (ratio of diethylether and treated virus material 1:1). Disruption by TNBP appeared more favourable not only because of the convenient performance but also due to the higher antibody-inducing ability of the product obtained. The suggested removal of TNBP from the disruption product by extraction into hexan is easy and reliable. Chemical analysis enabled precise detection of 0.1% TNBP in the "vaccine" product. The hexan-extracted "vaccine" contained less than 0.05% TNBP, a concentration non-toxic for mice.

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Sera obtained at enrollment in the study from patients suffering from moderate to sever dysplasia (cervical intraepithelial neoplasia grade II), carcinoma in situ (cervical intraepithelial neoplasia grade III) and invasive carcinoma, or developing any of these conditions in the course of the prospective study, and from control subjects, were examined for herpes simplex type-2 (HSV-2) antibody presence. The controls were matched with the patients by age, age at first intercourse, number of sexual partners, smoking habits and history of diathermoelectrocoagulation of the ectopic epithelium and transformation zone of cervix. Only those subjects were selected as controls who remained free of pathological colposcopical and cytological findings throughout the observation period, i.e. for at least 4 years after their serum sample was obtained. The microneutralization test (MNT) and type-2-specific solid-phase radioimmunoassay (SPRIA) were used as serological tests. No difference in the prevalence of HSV-2 antibody between the patients and controls was revealed by either test. Various combinations of the results from the two tests also failed to show any difference between patients and controls. Moreover, no significant differences were observed in the prevalence of HSV-2 antibody between patients suffering from the various pathological conditions and those diagnosed at enrollment and later in the course of the study. These results do not provide any support for the hypothesis of the involvement of HSV-2 in cervical neoplasia.

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Recombinants between H3N2 human influenza viruses (A/Victoria/3/75 and A/Bangkok/1/79, low-yielding parents in chick embryos) and fowl plague virus (FPV, a high-yielding parent in chick embryos) have been obtained. The high reproductive capacity of recombinants in chick embryos has been shown to be due to the gene coding for M proteins.

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Sera from 48 tonsillar carcinoma (TC) patients, 48 matched controls and 16 recurrent exudative tonsillitis (RET) patients were examined for the presence of Epstein-Barr virus (EBV) associated nuclear antigen (EBNA), early antigen (EA) and virus capsid antigen (VCA). Higher prevalence and significantly higher antibody titres against all three EBV-associated antigens were observed in TC patients in comparison with controls and RET patients. Patients suffering from anaplastic TC had higher titres of antibodies against VCA and EA than TC patients with other histological diagnoses. Five out of 11 TC biopsies obtained from 9 patients were positive for EBV DNA at levels of 0.17, 4 to 5, 15 to 18 and in two cases 3 EBV genome equivalents per cellular genome. Among 16 RET patients, 4 were found positive at levels not exceeding 2.17 EBV genome equivalents per cellular genome. Higher titres of antibody against all EBV antigens were found in TC and RET patients with EBV DNA-positive tonsillar tissue than in those with EBV DNA-negative tonsillar tissue.

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Infection with vesicular stomatitis virus (VSV) of human diploid cells preinfected with the AD-169 strain of human cytomegalovirus (CMV) resulted in the formation of a VSV (CMV) pseudotype. Its formation was favored by increasing the bicarbonate content in doubly-infected cultures. The pseudotype was capable of infecting not only human but also rabbit cells. Pseudotype particles formed after infection with the tl 17 mutant of VSV, which carries a thermolabile lesion in its neutralization antigen, were more stable at 45 degrees than the original tl 17 virus. The pseudotype was used in the neutralization test with human sera. All sera positive for CMV antibody in the complement-fixation (CF) test were also reactive in the neutralization test. In addition, numerous sera negative for CMV antibody in the CF test neutralized the pseudotype.

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