Shingles is a viral infection that causes a painful rash, stemming from the varicella-zoster virus (VZV), the same virus responsible for chickenpox. After a chickenpox infection, VZV remains inactive in the body, potentially reactivating years later to cause shingles. The shingles vaccine is designed to prevent this reactivation and the associated disease. Many individuals wonder if they can transmit the virus to others after receiving the shingles vaccine.
Contagiousness and Vaccine Types
The contagiousness of a person after receiving a shingles vaccine depends significantly on the type of vaccine administered. Currently, Shingrix is the primary shingles vaccine recommended in the United States and is not a live vaccine. It contains only a piece of the varicella-zoster virus, not the live virus itself. Therefore, individuals vaccinated with Shingrix are not contagious and can interact with anyone without concern for viral transmission.
An older vaccine, Zostavax, was a live attenuated vaccine, meaning it contained a weakened form of the live varicella-zoster virus. Zostavax was discontinued in the U.S. in November 2020. While the risk of transmission from Zostavax was exceptionally low, a very small theoretical possibility of spreading the vaccine virus existed, primarily if a rash developed at the injection site. If such a rash occurred, the shedding of vaccine virus was most likely to happen, but transmission was still considered rare.
Who is at Risk and Precautions
The risk of transmitting the vaccine virus from a Zostavax recipient was considered extremely rare. However, if a Zostavax recipient developed a rash at the injection site, specific populations were theoretically more susceptible to exposure. These included severely immunocompromised individuals, pregnant women who had not had chickenpox, and newborns whose mothers had not had chickenpox. For Zostavax recipients who developed a vaccine-related rash, simple precautions such as keeping the rash covered until it crusted over and practicing good hand hygiene were advised.
It is important to note that for the vast majority of people, regardless of whether they received Zostavax or the currently recommended Shingrix vaccine, no special precautions are necessary after vaccination. Shingrix, being a non-live vaccine, poses no risk of transmitting the virus.
Shingles Disease vs. Vaccine Shedding
Active shingles disease is contagious through direct contact with the fluid from the blisters. If someone who has not had chickenpox or been vaccinated against it comes into direct contact with this fluid, they can contract chickenpox, not shingles. The contagious period for shingles disease typically lasts from when the rash appears until all blisters have crusted over, which usually takes 7 to 10 days.
This is distinct from the minimal or non-existent risk of viral shedding from the shingles vaccines. While the older Zostavax vaccine had a theoretical, extremely low risk of shedding the weakened virus, Shingrix, the currently available vaccine, does not contain live virus and therefore cannot cause infection in others. The primary purpose of the shingles vaccine is to prevent the painful disease itself, thereby also eliminating the risk of transmitting the varicella-zoster virus through active shingles lesions.