Smallpox Vaccine and Cancer

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Smallpox vaccine safety for people with cancer

Should people with cancer avoid the vaccine?

Cancer itself, as well as many cancer treatments, suppress or weaken the immune system. Anyone with cancer whose immune system is not working well should not get a smallpox vaccination because of the increased risk of serious side effects. This means that any person with cancer should NOT get the vaccine unless a smallpox outbreak occurs and they have already been exposed to smallpox. And even in this case, they should talk to their cancer doctor before getting vaccinated.

What kinds of precautions should people with cancer take?

People with cancer should avoid close contact with people who recently have been vaccinated unless the vaccination site is covered with a gauze bandage and a special plastic dressing (called a semi-permeable dressing).

What is “close contact?”

The CDC defines close contact as household or similar intimate physical contact. This means that anyone who has had a smallpox vaccination should not live with, share a bed with, or share a bathroom with a person who has active cancer for at least 21 days after the vaccination.

Likewise, a person with cancer should not live with, or share a bed or bathroom with anyone who has had a smallpox vaccination within 21 days of their being vaccinated.

Because the vaccinia virus is passed through direct contact, it’s not likely that a person will become infected at the workplace, in public places, or by using public transportation.

The main concern for people who have close, physical contact with someone who has been vaccinated is that the vaccinia virus can be spread from the vaccination site. Vaccinia is spread by touching a vaccination site before it has healed and then touching another part of the body or touching someone else. It can also be spread by touching bandages, clothing, towels, or other material that picks up live virus from the vaccination site. The vaccination site often becomes itchy, which may lead to scratching, rubbing, or touching the site. This increases the risk that the virus will end up on other parts of the body, or on clothing and other surfaces.

How can a cancer patient know if they have been infected with vaccinia?

If a person with cancer gets a vaccinia infection, symptoms might include rash, fever, tiredness, and head and body aches. The rash starts in the mouth and then appears on the skin. Anyone who may have smallpox should see a doctor who specializes in infections (an infectious disease specialist) right away.

Last Medical Review: 02/24/2014
Last Revised: 02/24/2014