Kyasanur forest disease virus: viremia and challenge studies in monkeys with evidence of cross-protection by Langat virus infection.

Kyasanur Forest Disease Virus (KFDV), discovered in 1957, is a member of the tick-borne encephalitis virus (TBEV) complex. Diseases caused by members of the TBEV complex occur in many parts of the world. KFDV produces a hemorrhagic fever in humans in South India and fatal illnesses in both species of monkeys in the area, the black faced langur (Presbytis entellus) and the bonnet macaque (Macaca radiata).

Field evaluation of formalin inactivated Kyasanur forest disease virus tissue culture vaccine in three districts of Karnataka state.

A formalin inactivated Kyasanur forest disease (KFD) virus tissue culture vaccine produced by the health department of the State Government of Karnataka at Shimoga was administered in Shimoga, Uttar Kannada and Chikmangalur districts during 1990-92 KFD epidemic seasons. The selection of places for vaccination was based on the prevalence of KFD activity in previous years; villages adjacent to KFD affected areas and the villages from which mortality in monkeys was reported. A total of 284 villages was covered under vaccination; 26850 individuals received one dose whereas, 61302 received two doses of vaccine.

Serological response to Japanese encephalitis vaccine in a group of school children in South Arcot district of Tamil Nadu.

A trial with Biken Japanese encephalitis (JE) vaccine made in Japan was carried out in South Arcot district of Tamil Nadu state, India. A total of 113 school children were included in the trial. The efficacy (as determined by serological response) and safety of the vaccine were evaluated.

Circulating interferon-alpha in patients with Kyasanur forest disease.

Endogenous interferon (IFN) levels were monitored in acute (51) and convalescent phase (19) sera collected from patients suffering from Kyasanur forest disease (KFD). Levels of circulating IFN in the acute samples (GM 216.3 +/- 8.

Characterization of & induction of immune response to anti-idiotypic antibodies for JE virus.

Anti-idiotypic antibodies (anti-Ids, Ab2s) were prepared by immunizing rabbits with two murine monoclonal antibodies (Ab1) having specificities for two independent haemagglutinin (HA) epitopes on JE virus [viz., Hs-1, monoclonal antibody (MAb) specific for Japanese encephalitis virus (JEV) and Hx-1, MAb common to flaviviruses]. Anti-Hs-1 (S-Ab2) and Anti-Hx-1 (X-Ab2) reacted specifically with the immunizing Ab1.

Epitope analysis of strains of Japanese encephalitis virus by monoclonal antibodies.

Twenty one strains of Japanese encephalitis (JE) virus, including 16 from India, were compared antigenically on the basis of their reactivity in immunofluorescence (IF), haemagglutination inhibition (HI), ELISA with captured antigen (ECA), and neutralization (N) tests with JE monoclonal antibodies (MAbs). These MAbs represented three domains of distinct epitopes on the envelope protein, designated as Hs-1 to 4 (JE specific in HI), Hx-1 to 5 (flavivirus cross reactive in HI) and NHs-1 to 2 (non-HI JE virus specific). Fifteen of the 21 strains studied were placed in group I.

Characteristics of single-radial-diffusion and autoradiographic zone size enhancement (ZE) techniques for poliovirus antigens.

The reactions of polioviruses in single-radial-immuno diffusion (SRD) tests were investigated with a view to developing accurate and sensitive antigen assay systems. In direct SRD tests, employing high concentrations of immune poliovirus serum in agarose gels, poliovirus D antigens produced D antigens produced clear reaction zones demonstrated by protein staining. The reactions were type specific for polioviruses of types 1, 2 and 3 but the tests were of low sensitivity being applicable only to the assay of virus concentrates.

Immunoassay of poliovirus antigens by single-radial-diffusion: development and characteristics of a sensitive autoradiographic zone size enhancement (ZE) technique.

The reactions of polioviruses in single-radial-immunodiffusion (SRD) tests were investigated with a view to developing accurate and sensitive antigen assay systems. In direct SRD tests, employing high concentrations of immune poliovirus serum in agarose gels, poliovirus D-antigens produced clear reaction zones demonstrated by protein staining. The reactions were type-specific for polioviruses of types 1, 2 and 3 but the tests were of low sensitivity, being applicable only to the assay of virus concentrates.

The preparation of specific immune sera against type 3 poliovirus D-antigen and C-antigen and the demonstration of two C-antigenic components in vaccine strain populations.

Animals were immunized with purified D-antigen or C-antigen of type 3 poliovirus to produce specific antisera which were used to analyse the antigenic characteristics of the progeny virus in harvests from poliovirus type 3-infected cells. An examination of the virus progeny present at 24 h p.i.