Chickenpox and shingles may be closely related, but vaccination for the two is a separate affair. The pair share a root disease, varicella zoster, that activates to create each virus.
And yet, you need separate vaccines to prevent each disease.
Why is this? Why wouldn’t the same vaccine work for both? There are a few reasons.
The initial difference between the two is that chickenpox tends to affect younger children. Shingles is much more associated with the elderly, or at the very least adults. Chickenpox and shingles may come from the same virus, but that age difference is key to the need for two vaccines.
The immune systems of children and adults are different from one another and need to be treated in different ways. The older you get, the more likely you are to get shingles due to your changing immune system.
Chickenpox is also highly contagious, while shingles is noninfectious. A person who’s never had chickenpox can contract the virus from someone infected with shingles.
Despite an available vaccine that’s 90 percent effective, there are over 4 million chickenpox cases in the United States every year.
The chickenpox vaccine comes in two separate doses. The vaccine for varicella zoster contains live, attenuated varicella zoster virus. For children, the first dose should be taken when they are around 12 months, with the next dose administered around the age of four.
Shingles, meanwhile, isn’t prevented with just a chickenpox vaccine. This shared root disease means that anyone who has had chickenpox can also get shingles later in life. Although shingles is more common with individuals who are over 50, younger individuals can also get it. According to the CDC, about one million shingles cases occur each year.
With no instance of a live virus in the shingles vaccine, it is made specifically for that older age group of 50 years and above. The vaccine is proving 90 percent effective in preventing shingles for different age groups, but is still unable to prevent chickenpox.
That lack of a live virus is the key to our two very different vaccines.
The shingles vaccine contains a protein that is separate from that shared varicella zoster virus. With this protein, instead of the live virus, there’s much less of a chance for adverse effects in the older age group.
Vaccines with live viruses can pose a risk to individuals with a weakened immune system. Vaccines that use a live virus only contain a much weaker version of the illness. Even this limited virus poses to much of a risk for the weakened immune system in the older age group.
Written for Passport Health by Kaitlyn Luckow. Kaitlyn is a freelance writer, photographer and English teacher in Milwaukee. She has a passion for capturing and writing other people’s stories. You can find her at sayhellostory.com.