• Natural Product Sciences
• /
• v.5 no.2
• /
• pp.107-111
• /
• 1999

To investigate less toxic antiviral agents from Basidiomycetes, EA, the water soluble substance, was isolated from the carpophores of Elfvingia applanata (pers.) Karst. Anti-varicella zoster virus (Oka strain; anti-VZV/Oka) activity of EA was examined in MRC-5 cells by plaque reduction assay in vitro. And the combined antiviral effects of EA with nucleoside anti-VZV agents, acyclovir and vidarabine, were examined on the multiplication of VZV/Oka. EA exhibited a concentration-dependent reduction in the plaque formation of VZV/Oka with a 50% effective concentration $(EC_{50})$ of $464.14\;{\mu}g/ml$. The results of combination assay were evaluated by the combination index (CI) that was calculated by the multiple drug effect analysis. The combination of EA with acyclovir showed more potent synergism with CI values of $0.18{\sim}0.62$ for $50{\sim}90%$ effective levels than that of EA with vidarabine with CI values of $0.67{\sim}1.04$.

• Archives of Pharmacal Research
• /
• v.23 no.4
• /
• pp.418-423
• /
• 2000

Oka strain VR-795 (Varicella Zoster Virus, VZV) of American Type Culture Collection (ATCC) has been used for chickenpox vaccine production. In order to use this strain for vaccine production, the strain must be identified and its stability must be confirmed. The identification of the Oka strain has been confirmed using Restriction Fragment Length Polymorphism (RFLP) and DNA sequence analysis of glycoprotein-II (gp-II). The amino acid sequences of Oka deduced from the DNA sequence of gp-II have changed at three amino acids against Ellen and at one amino acid against Webster. To prove the stability of the Oka strain during the passage, RFLP and DNA sequence analyses were also used with 11, 15 and 23 times of virus passage. We found that the Oka strain was stable at passages of up to 23 times, based on the RFLP and DNA sequence analyses. The confirmed Oka strain was renamed as BR-Oka for the purposes of chickenpox vaccine production.

• The Korean Journal of Mycology
• /
• v.27 no.3 s.90
• /
• pp.237-241
• /
• 1999

To search for less toxic antiviral agents from Basidiomycetes, the water soluble components (=EA), were isolated from the carpophores of Elfvingia applanata (Pers.) Karst. Anti-varicella zoster virus (Oka strain; anti-VZV/Oka) activity of EA was examined in MRC-5 cells by plaque reduction assay in vitro. And the combined antiviral effects of EA with interferon (IFN) alpha or IFN gamma were examined on the multiplication of VZV/Oka. EA exhibited a dose-dependent reduction in the plaque formation of VZV/Oka with 50% effective concentration $(EC_{50})$ of $464.14\;{\mu}g/ml$. The results of the combination assay were evaluated by the combination index (CI) that was calculated by the multiple drug effect analysis. The combination of EA with IFN alpha showed partially synergistic or additive effects with CI values of $0.83{\sim}1.09$ for 50%, 70%, 90% effective levels, and those with IFN gamma showed antagonism with CI values of $1.20{\sim}1.24$.

• KSBB Journal
• /
• v.11 no.2
• /
• pp.254-261
• /
• 1996

Attenuated varicella-zoster virus (VZV) was propagated in human lung fibroblast (HLF) cells Among media tested in this work, DMEM was the best medium for the growth of HLF cells. Because HLF was a normal finite cell line, cell growth late was dependent on the age of HLF cells. When the population doubling level (PDL) was higher than 46, apoptosis of HLF cells started and cell growth rate decreased. The optimum temperature for the cell growth and virus propagation in the T-flask culture was $37^{\circ}C$. In a microcarrier culture system in which Cytodex-3 was used for the VZV propagation in spinner vessels, the yield of plaque forming cells was lower than that in the T-flask culture. The relatively high shear environment near microcarriers was thought to cause the low yield of VZV in the microcarrier culture system.

• Pediatric Infection and Vaccine
• /
• v.7 no.1
• /
• pp.129-135
• /
• 2000

Purpose : We previously reported the short-term immunogenecity and safety of 47 passaged Oka strain live attenuated varicella vaccine in healthy children in 1997. Now, we conducted this two-year follow-up study to confirm the maintenance of immunity, the occurrence of natural varicella infection and the activation of vaccine induced latent infection on the same vaccine. Methods : 99 children who had been immunized by 47 passaged Oka strain live attenuated varicella vaccine in 1997 were followed up by questionnaire, and 46 children out of study group were followed up serologically. They were asked to report any instance of varicella or herpes zoster since they had been immunized. If there was any evidence of varicella or herpes zoster, they should be clinically or serologically confirmed by doctor. Also, those patients' parents were asked to report any instance of varicella or herpes zoster in their family, playmate, kindergarten, school, or other settings. The immunity to VZV was confirmed by EIA and FAMA test. Results : 6 recipients developed breakthrough varicella after exposure to VZV in family, kindergarten and school during follow-up period. However, clinical features of those patients were very mild and self limited without therapy. And none of the recipients developed herpes zoster during this observation period. The results of EIA test showed that study subjects were all seropositive except one, and the antibody titers and GMT of FAMA test were seropositively maintained in all subjects. Statistically, the antibody titers of EIA and FAMA test confirmed two years after vaccination were higher than those results confirmed one month after vaccination. Conclusion : Our study results suggest that the immunity of 47 passaged Oka strain live attenuated varicella is well maintained until 2 years later after vaccination, and mild natural infection after exposure to VZV can be occurred with low rate. There were not developing zoster in study vaccine after vaccination for two-years.

• Clinical and Experimental Pediatrics
• /
• v.51 no.4
• /
• pp.377-382
• /
• 2008

Purpose : The aim of this study is to assess the usefulness of skin test by an inactivated, 1/50 diluted solution of attenuated varicella vaccine in evaluating the immune status to varicella. Methods : Total 41 subjects (22 males, 19 females, aged 1-32 years) were enrolled from July to August, 2005. Past medical history including varicella infection, varicella vaccination were investigated through questionnaires. The skin test solution was prepared from solution of attenuated varicella vaccine(Oka strain) which was inactivated by exposure to room temperature for 10 days and diluted at 1/50 with normal saline. Skin test was done by injecting 0.1 mL of the solution intradermally into the volar surface of the right forearm and sterile normal saline was used as a control on the left forearm. Positive reaction was defined when the transverse diameter of the induration was 5 mm or more. Serum varicella zoster virus specific IgG antibody test by ELISA (enzyme-linked immunosorbent assay) was done. Results : In adults, the sensitivity of the varicella zoster virus skin test compared to ELISA was 94.7% and the positive predictive value was 100%. In children, both the positive predictive value and specificity were 100% but the sensitivity and the negative predictive value were 50% and 30.7% respectively. Children showed smaller skin test reactivity compared to adults. Conclusion : The varicella zoster virus skin test using inactivated, 1/50 diluted solution of attenuated varicella vaccine was proved as one of the useful tools for evaluating the immunity and susceptibility of the varicella zoster virus.