Can I Spread Virus After Vaccination?

Q:  Is it possible to transmit the zoster virus to an unvaccinated infant after an adult gets the shingles vaccine?

A:  This is one of the many great questions that I received about the Zostavax shingles vaccine after my recent columns on it.

Zostavax is a live vaccine, meaning that the virus it contains (varicella-zoster) has been altered but not destroyed. Product information on Zostavax states that "transmission of the zoster virus may occur rarely to susceptible hosts," but this risk is theoretical and has been extrapolated from information that we have on other live vaccines.

In theory, any live vaccine has the chance of transmission to susceptible hosts.

So technically, an infant who has not been vaccinated against varicella could be at risk of getting chickenpox from an adult who has recently been vaccinated against shingles, but the chance of it actually happening would be extremely rare.

The manufacturer of the Zostavax vaccine (Merck & Co.) was unable to confirm if there have been any cases of transmission of the virus to a susceptible individual.

The zoster virus is usually transmitted through contact with an open shingles lesion. If you do develop a blister-like local reaction or a chickenpox-type rash after getting the Zostavax vaccine, keep the affected areas covered to avoid transmission. You are considered potentially contagious as long as a lesion is present and draining.

For more discussion on this interesting topic, see Vaccine Can Prevent Shingles and Its Debilitating Pain; All About Zostavax; and Age and the Shingles Vaccine.

Deidre L. Faust, MD, is a Staff Physician (Internal Medicine) at the Medical College of Wisconsin's Plank Road Clinic. Her column appears in the Milwaukee Journal-Sentinel.