| Gi-Eun Rhie | 5 Articles |
Objectives
Monkeypox outbreaks in nonendemic countries have been reported since early May 2022. The first case of monkeypox in the Republic of Korea was confirmed in a patient who traveled to Europe in June 2022, and an attempt was made to isolate and identify the monkeypox virus (MPXV) from the patient’s specimens. Methods Clinical specimens from the patient were inoculated in Vero E6 cells. The isolated virus was identified as MPXV by the observation of cytopathic effects on Vero E6 cells, transmission electron microscopy, conventional polymerase chain reaction (PCR), and sequencing of PCR products. Results Cytopathic effects were observed in Vero E6 cells that were inoculated with skin lesion swab eluates. After multiple passages from the primary culture, orthopoxvirus morphology was observed using transmission electron microscopy. In addition, both MPXV-specific (F3L and ATI) and orthopoxvirus-specific genes (A39R, B2R, and HA) were confirmed by conventional PCR and Sanger sequencing. Conclusion These results indicate the successful isolation and identification of MPXV from the first patient in the Republic of Korea. The isolated virus was named MPXV-ROK-P1-2022. Citations
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<p>Since a novel beta-coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in December 2019, there has been a rapid global spread of the virus. Genomic surveillance was conducted on samples isolated from infected individuals to monitor the spread of genetic variants of SARS-CoV-2 in Korea. The Korea Disease Control and Prevention Agency performed whole genome sequencing of SARS-CoV-2 in Korea for 1 year (January 2020 to January 2021). A total of 2,488 SARS-CoV-2 cases were sequenced (including 648 cases from abroad). Initially, the prevalent clades of SARS-CoV-2 were the S and V clades, however, by March 2020, GH clade was the most dominant. Only international travelers were identified as having G or GR clades, and since the first variant 501Y.V1 was identified (from a traveler from the United Kingdom on December 22<sup>nd</sup>, 2020), a total of 27 variants of 501Y.V1, 501Y.V2, and 484K.V2 have been classified (as of January 25<sup>th</sup>, 2021). The results in this study indicated that quarantining of travelers entering Korea successfully prevented dissemination of the SARS-CoV-2 variants in Korea.</p>
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<title>Objectives</title>
<p>The Korea Centers for Disease Control and Prevention has published “A Guideline for Unknown Disease Outbreaks (UDO).” The aim of this report was to introduce tabletop exercises (TTX) to prepare for UDO in the future.</p></sec>
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<title>Methods</title>
<p>The UDO Laboratory Analyses Task Force in Korea Centers for Disease Control and Prevention in April 2018, assigned unknown diseases into 5 syndromes, designed an algorithm for diagnosis, and made a panel list for diagnosis by exclusion. Using the guidelines and laboratory analyses for UDO, TTX were introduced.</p></sec>
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<title>Results</title>
<p>Since September 9<sup>th</sup>, 2018, the UDO Laboratory Analyses Task Force has been preparing TTX based on a scenario of an outbreak caused by a novel coronavirus. In December 2019, through TTX, individual missions, epidemiological investigations, sample treatments, diagnosis by exclusions, and next generation sequencing analysis were discussed, and a novel coronavirus was identified as the causal pathogen.</p></sec>
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<title>Conclusion</title>
<p>Guideline and laboratory analyses for UDO successfully applied in TTX. Conclusions drawn from TTX could be applied effectively in the analyses for the initial response to COVID-19, an ongoing epidemic of 2019 – 2020. Therefore, TTX should continuously be conducted for the response and preparation against UDO.</p></sec>
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Objective
Recombinant protective antigen (rPA) is the active pharmaceutical ingredient of a second generation anthrax vaccine undergoing clinical trials both in Korea and the USA. By using the rPA produced from <i>Bacillus brevis </i>pNU212 expression system, correlations of serological immune response to anthrax protection efficacy were analyzed in a guinea pig model. Methods Serological responses of rPA anthrax vaccine were investigated in guinea pigs that were given single or two injections (interval of 4 weeks) of various amounts of rPA combined with aluminumhydroxide adjuvant. Guinea pigs were subsequently challenged by the intramuscular injection with 30 half-lethal doses (30LD<sub>50</sub>) of virulent <i>Bacillus anthracis </i>spores. Serumantibody titerswere determined by anti-PA IgGELISA and the ability of antibodies to neutralize the cytotoxicity of lethal toxin on J774A.1 cell was measured through the toxin neutralizing antibody (TNA) assay. Results To examine correlations between survival rate and antibody titers, correlation between neutralizing antibody titers and the extent of protection was determined. Toxin neutralization titers of at least 1176 were sufficient to confer protection against a dose of 30LD<sub>50</sub> of virulent anthrax spores of the H9401 strain. Such consistency in the correlation was not observed from those antibody titers determined by ELISA. Conclusion Neutralizing-antibody titers can be used as a surrogate marker. Citations
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