Published online by Cambridge University Press: 02 January 2015
To compare the ability of 2 types of dressings to contain vaccinia virus after smallpox vaccination.
Prospective, nonrandomized trial.
The smallpox vaccination clinic in a medium-sized military hospital.
Ninety-seven active-duty military members who received smallpox vaccination in accordance with US Department of Defense and Centers for Disease Control and Prevention guidelines.
The first 40 participants enrolled were instructed to cover their vaccination sites with a semipermeable membrane placed over a separate gauze pad, and the subsequent 57 participants were given a semipermeable membrane bonded to an absorbent pad. Swab samples of the external surface of the dressing were collected 7 and 21 days after vaccination. Real-time quantitative polymerase chain reaction was used to detect vaccinia DNA in the samples.
The rate of vaccinia DNA detection was significantly higher for samples obtained from vaccinees who were using the separate gauze and semipermeable membrane, compared with the vacinees who were using the gauze-impregnated semipermeable membrane (22% vs 2.2%; P = .008; odds ratio, 12.3 [95% confidence interval, 1.4-567.4]).
A gauze-impregnated semipermeable membrane more effectively reduced viral passage to the external surface of the dressing than did a semipermeable membrane placed over a separate gauze pad. Routine use of such dressings following smallpox vaccination might reduce the incidence of autoinoculation and secondary transmission.