I got a 3rd Moderna vaccine dose at CVS because I have cancer. I was worried about the side effects, but it was worth it.

• Andrea Kjelgaard, 44, is a nurse on leave based in Castle Rock, Colorado.
• She is immunocompromised from having cancer, so she received a third dose of the COVID-19 vaccine.
• This is what she says getting the shot at CVS was like, as told to the freelance writer Suzie Glassman.

This as-told-to essay is based on a transcribed conversation with Andrea Kjelgaard, a nurse in Colorado, about receiving the Moderna vaccine. It has been edited for length and clarity. Editor's note: Kjelgaard and the author are friends.

My journey with cancer began in 2007. A year and a half earlier, doctors noticed a nodule in the right lower lobe of my lung during a scan for a kidney stone. They weren't sure what it was, so we agreed to take another scan in the future. When I went back, the nodule had grown from the size of a pea to a half dollar. I had a biopsy, and that's when I learned I had a rare cancer called epithelioid hemangioendothelioma, or EHE.

Doctors removed the nodules surgically, and I lived cancer-free for the next seven years. During that time, I got married and had two children. I enjoyed life as a nurse working at a small surgery center not far from where I lived in Castle Rock, Colorado. I was thriving in both my personal and professional life, so it came as a huge shock when the cancer returned in 2014.

Once again, doctors removed the tumors. But I couldn't believe my bad luck when I found a lump in my breast during a self-exam only a few months later. After a double mastectomy, several rounds of chemotherapy, and intense radiation, I was once again cancer-free. But the radiation left my left lung scarred and not functioning at 100%.

When COVID-19 took over the news by early March 2020, I had an awful feeling in my gut.

I was already dealing with fluid in my lung, and the fear of catching the virus was debilitating. My husband is an anesthesiologist, so each day he went to work felt like sending him to war. I feared he'd get sick, and I panicked daily that he'd give it to me.

I was desperate to put space between myself and the virus, so I packed up my third- and fifth-grade kids and drove to my parents' house in Ohio. They weren't there, so we had the place to ourselves.

We kept up with remote school and isolated ourselves from the world. When the case counts were lower and I was confident my husband had enough PPE to protect himself and not bring the virus home, we came back.

Just as I began to relax and feel we could manage life with masks and a small social circle, the EHE returned.

A flood of biopsies, doctor's visits, and scans showed the cancer had spread to other parts of my body and couldn't be removed with a scalpel. I started intense chemotherapy right as the rest of the world rang in 2021.

Going through chemo without visitors was terrifying - even my husband had to wait in the car while I went inside. I'd never felt so alone. My world shrunk to the size of my house  -  mainly my bedroom. Friends wanted to bring food, walk my dogs, and clean my house, but I couldn't risk it. It's like I could see COVID crawling on everyone and everything.

In January, I asked my doctor about the vaccine.

I was worried it might make me really sick. I was a shell of my former self, unable to keep much of anything down. I needed reassurance the shot was safe for cancer patients.

She said, without hesitation, to get it as soon as I could. I got my first shot in early March, and I'm glad I did. I suffered no side effects other than a sore arm and a headache a few days later. I had the same experience with the second shot.

Suddenly I felt as if I had a layer of protection over me I didn't have before. I left the house again. I ran errands and drove my kids to places. When I read the news about booster shots for immunocompromised patients, once again, my doctor told me to go. On August 31, I walked into CVS, told the pharmacy staff I was a cancer patient, and had my third shot within minutes. I felt more fatigue the next day but still no fever or chills.

I understand when people are hesitant or scared of how they might react to the vaccine or the booster. But the security I feel having protection from COVID means I can enjoy company again, even as I continue chemo medication. I have hope for my future. If cancer (and isolation) has taught me anything, it's that time with loved ones is precious.

I've been a nurse all my career, and I believe in science. I say to anyone who is immunocompromised, as confidently as my doctor said to me: Get the vaccine and the booster. It's worth it.