Is the COVID Vaccine Safe while Breastfeeding?

Most doctors say yes

Aldene Zeno, MD
6 min readJan 28, 2021
Proud to be among the tier 1 citizens to get the COVID vaccine

When I posted a photo on social media of me getting my first Pfizer COVID vaccine, I wasn’t expecting to be trolled about my fertility. “Good lord, Please tell me you got your eggs frozen ‘just in case’ because you’ve just turned yourself into a science experiment,” said @sarah.woodspie (whoever that is). Although her claims are not true, which I’ll discuss later in this story, they are common, misinformed beliefs about the vaccine in popular media.

I was excited to get the vaccine. Relief, pride, and hope are the common sentiments I hear from healthcare workers who have already received the vaccine. This pandemic has hit everyone differently. For me, I know several people who have had COVID: people in my own household, friends, and unfortunately, several friends who’ve lost parents, in addition to a friend-of-a-friend who is my age and died. My partner had COVID during my pregnancy, which is an experience I will detail in a separate post. Every time I saw patients in clinic, saw patients after surgery in the hospital, and consulted on patients in the ICU, I had a legitimate fear of getting the virus. My colleagues on labor and delivery were seeing several COVID-positive patients weekly. I have been fortunate to not contract the virus myself.

I hear legitimate concerns from people about the vaccine. It is true that there are no other commercially-available mRNA vaccines, and the COVID vaccine is the first of this kind to be used in the general population. It is also not technically FDA-approved — it has an emergency use authorization. Because of this, there is no “real world” longterm data about the vaccine, otherwise called “post-market surveillance.” Beyond that, any concerns about the vaccine are theoretical because the scientific community has a basic understanding of how vaccines work. I’ve been surprised to find out people have some deeply-rooted beliefs about this vaccine, so in this story I want to share my own experience and understanding of the science behind the vaccine.

In some of my physician mom social media groups, breastfeeding women are proving that COVID antibodies are secreted in breastmilk by using tests like this one pictured. Image source: USCNews (https://news.usc.edu/170565/covid-19-antibody-study-coronavirus-infections-los-angeles-county/)

Why would I accept risks of the vaccine while I’m Breastfeeding?

I actually think of this question differently — I get to give my infant antibodies when she can’t mount a mature immune response herself. My daughter is currently 3 months old, and we know that infants do not start forming mature antibodies, or protective proteins against infections, until they are 6 months and older. Additionally, it is currently understood that children under 1 years old are actually at higher risk of severe disease with COVID compared to older children. These are both reasons that I looked forward to getting the vaccine, to pass on my protective antibodies to my daughter through breastmilk.

Will the COVID vaccine turn recipients into mutants?

No, and here’s why: mRNA (messenger ribonucleic acid) is a way for cells to make copies of genetic information to make proteins. On the other hand, genes are stored in DNA. The COVID vaccine is made of synthetic mRNA and it does NOT change our DNA. It never enters the vaccine recipients’ cell nuclei, where DNA is housed, so it does not cause cell mutations.

Scientists are confident that the vaccine won’t be harmful to pregnant or breastfeeding women

COVID vaccine mRNA encodes a partial protein unique to coronavirus called “spike protein.” Spike protein is the virus’s key for getting into hosts cells and causing infection. The false spike protein induced by the vaccine causes our body to respond as if it sees the whole thing. The body then forms protective antibodies, but the false protein can’t cause an infection (is not antigenic). The mRNA originally injected through the vaccine dissolves because it’s not stable enough to remain intact. Knowing this, we don’t believe the mRNA is transmitted through the placenta to fetuses in pregnant women, or through breastmilk to breastfed babies. However, the protective antibodies do get passed on to breastfed babies as well as growing fetuses.

Maybe an analogy for the COVID vaccine is like getting a bootleg version of a movie. The original movie (like the coronavirus spike protein) is recorded on a different device (like the vaccine mRNA), and copies of that information are created into a new, bootleg version of the movie (resulting in the false spike protein). When you watch the bootleg version, the viewer (like the immune cells in our body) knows that the movie is bootleg because it’s not like the original. In the case of the vaccine, the “bootleg” spike protein is only part of the protein compared to the original. However, at the end of the movie the viewer still has the same response to the bootleg movie as if it were the original movie (hence our immune response creates protective antibodies to the real coronavirus, despite only ever “seeing” the bootleg version of the spike protein).

What it’s like to get the shot

I scheduled my appointment online through my job at USC. They gave me 2 dates 3 weeks apart for the 1st and 2nd doses. My first dose took about an hour for registration, the vaccine, and a 15 minute waiting period afterwards to make sure I didn’t have adverse reactions. The second dose took almost 2 hours — the lines were just longer.

I didn’t feel anything after the first shot. After the second shot my arm was very sore, but that was tolerable. That night, though, about 12 hours after my dose I had horrible joint pain and muscle aches. It was enough to keep me up at night so I took a Tylenol and that was all I needed to get back to sleep. The next day I was tired, but hard to tell if I was more tired than normal-me, mom exhaustion. This is similar to what my friends have experienced with the second dose. As your body starts to make antibodies this also stimulates a mini immune response, so you get symptoms similar to COVID but in its mildest form. Common side effects with the second shot are mild fevers, fatigue or generally feeling unwell — all less intense and less duration than what the real coronavirus would cause.

Where do these vaccine misconceptions come from?

This is my favorite social media post explaining the origins for a lot of the myths about the vaccine from Dr. Vicki Chan:

@vickichanmd

I’ll end my story with this — I waited to get vaccinated until the Society for Maternal Fetal Medicine came out with a statement supporting COVID vaccine use in pregnant and lactating women. I had also seen the myths, but while I was undecided I wanted to get more info. At the end of the day the vaccine was the right thing for me and my baby based on the information I could find.

The vaccine is not the silver bullet many hoped for. We still have to socially distance, wear masks, wash our hands, and take all the public health measures needed to get this virus under control. Some people have legit reasons to not get this vaccine (ex. Serious adverse reaction to other vaccines), and some people just aren’t comfortable right now. Hopefully my story can help you get closer to making an informed decision.

--

--

Aldene Zeno, MD

Board-certified urogynecologist in Glendale, CA, and greater Los Angeles, increasing awareness of pelvic floor disorders, sexual dysfunction, and fitness.