Thursday, May 13, 2004 - 11:30 AM
4980

Vaccinia Contact Transfer: The DoD Experience

Mylene T. Huynh1, Laurie L. Duran2, Limone C. Collins, Jr.2, Robert Dana Bradshaw3, John D. Grabenstein4, and Renata J. M. Engler5. (1) Operational Prevention Division, USAF, 110 Luke Ave, Room 400, Bolling AFB, DC, USA, (2) DoD Vaccine HealthCare Center, Walter Reed Army Med Center, DC, USA, (3) Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Room A 1040A, Bethesda, MD, USA, (4) U.S. Army Medical Service Corps, AVIP Agency-OTSG, Skyline 5, Suite 401, 5111 Leesburg Pike, Falls Church, Virginia, USA, (5) Walter Reed National Vaccine Healthcare Center, Walter Reed Army Medical Center, Walter Reed Army Medical Center, 6900 Georgia Avenue, NW, Washington, DC, USA


BACKGROUND:
In December 2002, the Department of Defense (DoD) implemented the smallpox vaccination program (SVP) as preparedness against the potential use of smallpox as a biological weapon. Safety is our top priority. In this study, we will review the transmissibility of vaccinia virus in vaccinated military members.

OBJECTIVE:
To describe the military experience with vaccinia secondary transmission, including transmission in the workplace and healthcare settings, among family members and other situations.

METHOD:
Descriptive study of vaccinia secondary transmission (contact vaccinia) that occurred during the period, from December 13, 2002 through January 12, 2004. Cases were identified through VAERS reports, Service reports and laboratory data.

RESULT:
Among 548,438 military personnel vaccinated for smallpox, 29 cases of contact transfer were reported (20 laboratory confirmed, 5 probable and 4 suspect). All contact vaccinia transfer resulted from male primary vaccinees (rate of 1 per 20,000 overall, or 1.5 per 20,000 primary vaccinees). Majority of secondary transmission occurred among spouse or intimate sexual contacts (19/29), followed by friends during close contact sports (6/29; 5 in wrestling and 1 in basketball game). Others occurred among friends during hugging (2) and household child contacts (2). None of the contact cases had previously been vaccinated with smallpox and none developed systemic reactions (including eczema vaccinatum), and all fully recovered. During the same time period, 27,700 healthcare workers received smallpox vaccination and continued with their usual patient care responsibilities. There was no transmission of vaccinia in the healthcare setting.

CONCLUSION:
DoD experience with the rate of contract transmission is similar to historical rates but without any cases of eczema vaccinatum. Transmission is unlikely in casual or workplace settings, including healthcare settings. Transfer of vaccinia is most likely to result from male primary vaccinees to vaccinia-naiive individuals during episode of skin-to-skin contact. Our experience suggests that smallpox vaccination can be implemented without significant consequences of contact transfer events.

LEARNING OBJECTIVES:
Review the DoD experience with contact vaccinia

See more of The Military Experience with Vaccine Safety
See more of The 38th National Immunization Conference