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

Kim, Sung Han; Yeo, Sang Gu; Cho, Jae Hyun; Bang, Ji Whan; Kim, Hong Bin; Kim, Nam Joong; Jee, Youngmee; Cho, Haewol; Oh, Myoung don; Choe, Kang Won

Abstract

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.