Figure 1.

Dryvax^® consists of a mixed pool of vaccinia virus NYCBH strain. Six vaccinia virus clones were isolated and purified. These were all tested and Clone 2 (CL2) was found to have a virulence profile most closely resembling that of Dryvax^®. This clone was propagated on MRC-5 cells and purified to produce the vaccine, named ACAM1000™. Additional expansion was carried out on Vero cells to produce more than 200 million vaccine doses, and the vaccine was renamed ACAM2000™.

Abbreviation: NYCBH, New York City Board of Health.