Table 4.

Smallpox Vaccines

Vaccine	Pros	Cons	Stage of Development or Use
ACAM2000: Live vaccinia virus	Single-dose administration. A successful take is noted by observation of a lesion at the vaccination site. Lyophilized preparation for long-term storage.	Live viral vaccine that replicates in mammalian cells; autoinoculation and contact transmission are risks. In low- disease-risk situations, should not be used for individuals with immunocompromising conditions, history of eczema or atopic dermatitis, or pregnant females. Cardiac events postvaccination have been noted to occur.	Licensed vaccination in the United States. Currently available to specific populations from the Strategic National Stockpile.
Modified vaccinia Ankara; IMVAMUNE (US); IMVANEX (Europe): Attenuated vaccinia virus	The virus has limited replication in mammalian cells. No lesion produced at the vaccination site.	Two-dose administration by injection.	European Commission has authorized marketing for immunization of the general adult population, including those who are immunocompromised. Maintained in the United States’ Strategic National Stockpile.
LC16m8: Attenuated vaccinia virus	Single-dose administration. Exhibits a safer profile and less adverse events than ACAM2000 in human and animal vaccinations.	Attenuated virus that can still replicate in mammalian cells.	Licensed for use in Japan.