Development of New Preventive and Therapeutic Vaccines for Tuberculosis

Tuberculosis (TB) is a contagious disease that has been responsible for the death of one billion people in the last 200 years. Until now, the only vaccine approved for the prevention of TB is Bacillus Calmette-Guérin (BCG), which is prepared by attenuating Mycobacterium bovis. However, one of the limitations of BCG is that its preventive effect against pulmonary TB varies from person to person. Therefore, there arises a need for a new TB vaccine to replace or supplement BCG. In this review, we have summarized the findings of current clinical trials on preventive and therapeutic TB vaccine candidates. In addition, we have discussed a novel vaccination approach using the cell-based vaccine presenting early secretory antigenic target-6 (ESAT-6), which is a potent immunogenic antigen. The role of ESAT-6 in hosts has also been described.

A Delphi Study on National Public Vaccine Research and Development Policy in Korea / 보건행정학회지

Vaccination is the most powerful and useful preparation against infectious diseases. However, developing vaccines costs a lot and requires extensive long-term efforts. Therefore, the government should research and develop vaccines with a national-level policy. To greatly enhance the success rate of vaccine development, the policy should be set up considering priorities such as the current status of domestic research, the importance for public health, the urgency of research. The Delphi technique was utilized to draft this survey, through a brainstorming stage, then two inquiries, and finally the final panel meeting where unresolved items were discussed, to draw the conclusion. Among the results, firstly, the highest ranked item on centralized fields for vaccine development by the Ministry of Health was 'self-sufficiency of vaccines.' Secondly, 'emerging infectious disease' was most highly ranked in prioritized fields of vaccine development and research. Thirdly, for the vaccine that needs to be improved and developed further by the government to improve its efficacy and safety, BCG (Bacille de Calmette) for tuberculosis was ranked the highest on both types (intradermal and subcutaneous injection) from National Immunization Programme (NIP) and non-NIP. As for the high risk pathogens, 'anthrax' and 'smallpox' were first and second, consecutively. Lastly, 'development and control of vaccine candidates' was ranked the highest for the area in need for technique development in order to improve domestic vaccine's research level. The results of this study will be put to good use as basic data for the national vaccine research and development (R&D) policy of the country. This study was first step and more studies should be carried out for the final decision of the national vaccine R&D priority.

Antiviral Activity of Hederasaponin B from Hedera helix against Enterovirus 71 Subgenotypes C3 and C4a

Enterovirus 71 (EV71) is the predominant cause of hand, foot and mouth disease (HFMD). The antiviral activity of hederasaponin B from Hedera helix against EV71 subgenotypes C3 and C4a was evaluated in vero cells. In the current study, the antiviral activity of hederasaponin B against EV71 C3 and C4a was determined by cytopathic effect (CPE) reduction method and western blot assay. Our results demonstrated that hederasaponin B and 30% ethanol extract of Hedera helix containing hederasaponin B showed significant antiviral activity against EV71 subgenotypes C3 and C4a by reducing the formation of a visible CPE. Hederasaponin B also inhibited the viral VP2 protein expression, suggesting the inhibition of viral capsid protein synthesis.These results suggest that hederasaponin B and Hedera helix extract containing hederasaponin B can be novel drug candidates with broad-spectrum antiviral activity against various subgenotypes of EV71.

Antiviral Activity of Hederasaponin B from Hedera helix against Enterovirus 71 Subgenotypes C3 and C4a

Enterovirus 71 (EV71) is the predominant cause of hand, foot and mouth disease (HFMD). The antiviral activity of hederasaponin B from Hedera helix against EV71 subgenotypes C3 and C4a was evaluated in vero cells. In the current study, the antiviral activity of hederasaponin B against EV71 C3 and C4a was determined by cytopathic effect (CPE) reduction method and western blot assay. Our results demonstrated that hederasaponin B and 30% ethanol extract of Hedera helix containing hederasaponin B showed significant antiviral activity against EV71 subgenotypes C3 and C4a by reducing the formation of a visible CPE. Hederasaponin B also inhibited the viral VP2 protein expression, suggesting the inhibition of viral capsid protein synthesis.These results suggest that hederasaponin B and Hedera helix extract containing hederasaponin B can be novel drug candidates with broad-spectrum antiviral activity against various subgenotypes of EV71.

A Quantitative Comparison of Vaccinia Virus Shedding from Conventional Dressing Sites and Vaccination Lesions after Smallpox Vaccination / 감염과화학요법

BACKGROUND: We compared vaccinia virus shedding from the vaccine inoculation site (vaccination lesion) and two sites of a dressing covering the vaccination site; the outer surface of the semipermeable dressing (outer surface) and the inner surface of the semipermeable dressing, that is, the surface of a folded gauze under the semipermeable membrane (gauze surface) MATERIAL AND METHODS: Subjects were recruited from the volunteers who participated in a clinical trial of the efficacy of a 1:10 dilution of Lancy-Vaxina? (Berna Biotech, Switzerland), and were seen every 2-3 days (days 6, 8, 10, 13, and 15 after smallpox vaccination) for scheduled dressing changes. Swab specimens were obtained from the vaccination lesion, the outer surface, and the gauze surface. Quantitative viral culture assays for these specimens were done. RESULTS: Vaccinia virus was recovered from 126 (81%) of the 156 vaccination lesion samples collected from the 40 participants. A high virus titer was recovered from the vaccination lesion (geometric mean titer (log10)=3.91 on day 8). Of the 39 swab samples obtained from the gauze surface of the gauze, 16 (41%) were positive for virus. An intermediate titer was recovered from the gauze surface (geometric mean titer (log10)=0.91 on day 8). Of the 133 swab samples obtained from the outer surface, only one (0.8%) was positive for vaccinia. No virus was recovered from the outer surface on day 8. CONCLUSION: Our findings suggest that the addition of a semipermeable dressing to the folded gauze further reduces viral shedding and therefore increases protection.

A Quantitative Comparison of Vaccinia Virus Shedding from Conventional Dressing Sites and Vaccination Lesions after Smallpox Vaccination / 감염과화학요법

BACKGROUND: We compared vaccinia virus shedding from the vaccine inoculation site (vaccination lesion) and two sites of a dressing covering the vaccination site; the outer surface of the semipermeable dressing (outer surface) and the inner surface of the semipermeable dressing, that is, the surface of a folded gauze under the semipermeable membrane (gauze surface) MATERIAL AND METHODS: Subjects were recruited from the volunteers who participated in a clinical trial of the efficacy of a 1:10 dilution of Lancy-Vaxina? (Berna Biotech, Switzerland), and were seen every 2-3 days (days 6, 8, 10, 13, and 15 after smallpox vaccination) for scheduled dressing changes. Swab specimens were obtained from the vaccination lesion, the outer surface, and the gauze surface. Quantitative viral culture assays for these specimens were done. RESULTS: Vaccinia virus was recovered from 126 (81%) of the 156 vaccination lesion samples collected from the 40 participants. A high virus titer was recovered from the vaccination lesion (geometric mean titer (log10)=3.91 on day 8). Of the 39 swab samples obtained from the gauze surface of the gauze, 16 (41%) were positive for virus. An intermediate titer was recovered from the gauze surface (geometric mean titer (log10)=0.91 on day 8). Of the 133 swab samples obtained from the outer surface, only one (0.8%) was positive for vaccinia. No virus was recovered from the outer surface on day 8. CONCLUSION: Our findings suggest that the addition of a semipermeable dressing to the folded gauze further reduces viral shedding and therefore increases protection.