Does radiation or chemo increase the risk of shingles?

srobinet, https://pmc.ncbi.nlm.nih.gov/articles/PMC7930445/
Shingrix is not a live vaccine and is declared safe during cancer treatment. Best to ask your oncologist, anyway. Best wishes.
I've been putting it off for years without good excuse.

Well from my recent experience with a shingles outbreak after receiving my 1st chemo treatment
I am here to tell you that yes chemo can cause a shingles outbreak . Look it up in a search bar.
I will say that the vaccination will likely lessen the severity of the outbreak though.
I've had the two vaccinations 6 mos apart a couple years ago.
My outbreak was confirmed by a Dr outside the cancer treatment facility.
The chemo weakens the immune system , a minor skin abrasion or cut can easily become infected as well.
Ask me how I know.

@srobinet, have you had shingles before? Have you talked to your oncologist about getting the shingles vaccine and when would be the best time during treatment?

@colleenyoung I have not had Shingles before. I have not started treatment yet as surgery will be the first step. I got my first Shingles vaccine about 2 weeks ago and am supposed to get the second one toward the end of March. I imagine by that time I will be in treatment so I definitely will check with my Oncologist.

Many years ago, I had a double mastectomy and ovaries removed at the same time. No radiation or chemo. I have a nerve disorder that caused unbearable pain from the abdominal surgery plus severe range of motion issues from the mastectomy. I got shingles a couples weeks afterwards while recovering from surgery apparently just from the stress or trauma to my body. The shingles pain was intense and lasted 2.5 weeks. It wasn’t fun.

I highly recommend the most recent shingles vaccine (2 doses). I had a mild case of shingles on my face decades ago before antivirals were available to treat it. It resulted in me developing trigeminal neuralgia which is the most wicked pain you can imagine. Now having breast cancer, I thank any lucky stars out there that my TN attacks have lessened over time. I can't imagine dealing with both.

So I'm in the get-this-vaccine camp. I think there is also recent evidence that having the vaccine may provide some protection against dementia:
https://med.stanford.edu/news/all-news/2025/03/shingles-vaccination-dementia.html
But I also advise discussing the timing of this vaccine with your oncologist. It could affect the best time to get this vaccine, i.e, it may be best to get it before chemo and/or radiation rather than during.