Quick version
Chickenpox vaccines contain a live, attenuated (weakened) varicella-zoster virus. The vaccine protects against chickenpox, but in some cases, the virus can remain dormant in the body's nervous system. If it reactivates later, it can cause shingles. This is uncommon, and studies on children show that the risk of shingles is lower after vaccination than after a natural chickenpox infection.
Why can you get shingles despite being vaccinated against chickenpox?
To develop shingles, the varicella-zoster virus must already be present in the body. This usually happens after having had chickenpox, but the weakened virus in a chickenpox vaccine can also establish a dormant infection. This means that a person who has never had chickenpox but has been vaccinated against the disease can, in rare cases, develop shingles later in life.
It is important to distinguish between three situations:
- You have had chickenpox: The virus remains dormant in the body and can later reactivate as shingles.
- You have never had chickenpox but have been vaccinated: In rare cases, the vaccine virus can reactivate and cause shingles.
- You have neither had chickenpox nor been vaccinated: If you have never been infected with the virus, there is no dormant virus that can cause shingles. However, you can still become infected and develop chickenpox.
For people vaccinated against chickenpox in adulthood, there is less research regarding the long-term risk of shingles compared to those vaccinated as children.
Vaccination against chickenpox does not mean that the risk of shingles disappears entirely. However, studies on children show that the risk of shingles is lower after vaccination than after a natural chickenpox infection. There is less research regarding the long-term risk for individuals who are vaccinated as adults.
Can the chickenpox vaccine cause shingles later in life?
Yes, but it is extremely rare. The chickenpox vaccine contains a live, attenuated virus that helps the immune system develop protection against the disease. Since it is still a live virus, it can in some cases establish a dormant infection in the nervous system.
If the vaccine virus reactivates later, it can cause shingles. However, it is very important to distinguish this possibility from the risk following a natural infection. According to studies on children, vaccination against chickenpox generally carries a significantly lower risk of shingles than contracting the disease itself.
For those who have never had chickenpox, vaccination is therefore still an important way to prevent an initial infection, provided the vaccine is medically appropriate.
If I get vaccinated against chickenpox as an adult, do I also need a shingles vaccine?
This depends entirely on your age, prior immunity, and individual medical circumstances. The vaccines for chickenpox and shingles serve different purposes.
- Chickenpox vaccine: Used to protect individuals who lack immunity against an initial infection. The vaccine contains a live, attenuated virus.
- Shingles vaccine (Shingrix): Used to reduce the risk of shingles and its complications. Shingrix does not contain live virus and therefore cannot cause either chickenpox or shingles.
Shingrix is not intended to prevent an initial chickenpox infection. If you have never had chickenpox and lack immunity, you should therefore consult a healthcare professional regarding appropriate vaccination.
The Public Health Agency of Sweden recommends shingles vaccination for individuals aged 65 and older. Since the vast majority of older adults have already had chickenpox, an antibody test is generally not required prior to vaccination.
Unsure if you’ve had chickenpox? Check your antibody levels
Many adults do not remember whether they had chickenpox as children. The infection may have been mild or occurred so early in life that it is not remembered.
If you have specific reasons to suspect that you have never had chickenpox, an antibody test can provide information about your past exposure to the varicella-zoster virus and your immune status. Several Swedish healthcare providers offer antibody analysis, and you can certainly request a referral from us at Testmottagningen; the analysis includes:
- VZV IgG antibodies: Can indicate whether you have previously been exposed to the virus through infection or vaccination and provide information about your immunity to chickenpox.
- VZV IgM antibodies: Can provide supplementary information regarding an immune response to a recent infection but are not reliable on their own for diagnosing an active infection.
A positive IgG result usually indicates a past infection or vaccination. A negative result, however, should be interpreted with some caution, as antibody levels can be low despite prior immunization. The antibody test cannot predict if or when you might develop shingles and is generally not required prior to shingles vaccination.
Read more about our antibody test for chickenpox and shingles.
