Letters Section Editor: Robert M. Golub, MD, Senior Editor.
To the Editor: Routine administration of the smallpox vaccine ended in the United States in 1972. With the reinitiation of the US smallpox vaccination program in 2002, the risk of transmission of vaccinia virus from a recently vaccinated person to a susceptible host is a concern. Secondary transmission is biologically plausible because of evidence of viral persistence in vaccinees. Vaccinia virus has been cultured from the oropharynx of vaccine recipients with a normal course following vaccination.1 In the 1960s and 1970s, it was isolated from the blood and urine of a limited number of vaccine recipients who had complications following vaccination.2 More sensitive molecular techniques are now available for detecting viruses in clinical specimens. We describe findings using real-time polymerase chain reaction (PCR) to detect vaccinia DNA in smallpox vaccine recipients.
Savona MR, Dela Cruz WP, Jones MS, Thornton JA, Xia D, Hadfield TL, Danaher PJ. Detection of Vaccinia DNA in the Blood Following Smallpox Vaccination. JAMA. 2006;295(16):1895-1900. doi:10.1001/jama.295.16.1898