Smallpox Vaccine

To the Editor:

Senator Bill Frist's Aug. 9 Op-Ed article, "Deciding Who Is to Be Protected Against Smallpox," which calls for giving all Americans the option to receive the vaccination against smallpox, does not mention that vaccinia virus -- the weakened form of smallpox in current vaccines -- spreads readily from vaccinees to others through contact with the vaccination lesion. Inevitably, many thousands of H.I.V.-infected people would be exposed, and most would develop potentially fatal infections.

We need to develop smallpox vaccines that are safe in immunosuppressed people before we embark on mass immunization. This is feasible, but it will take time.