At the release of the COVID-19 vaccine, there was discussion that it may cause infertility. This was based on the fact that a small protein segment of the virus’s outer envelope is similar to the protein called Syncytin-1, which is involved in normal placental function, primarily implantation.
The vaccines from Pfizer and Moderna are RNA vaccines which, when injected, cause your own cells, reportedly muscle cells, to produce a small piece of the viral envelop called a “spike protein”. The body then produces antibodies to that protein so if you become infected, the antibodies attack the virus at the place this “spike protein” sequence exists.
Questions still exist about how much of the sequence is actually shared between Syncytin-1 and the “spike protein” produced by your body after vaccination. As a further complication, there are likely differences between the various vaccines. One reference I found indicates that the sequence that is shared by both the “spike protein” and Syncytin-1 for the Pfizer vaccine is only 4 amino acids in length. https://www.thejournal.ie/pfizer-covid-19-vaccine-fertility-5294308-Dec2020/
The scenario that the body produces antibodies from the vaccine that subsequently attack the placenta can only be considered a remote possibility. The role of the immune system in pregnancy, however, is still an enigma. We know that it is a delicately balanced process and that disturbing this process can have implications for pregnancy and future fertility. I believe this indicates the need for caution. This reference suggests that multiple miscarriages have already been reported.
More recently, reports of menstrual cycle disruption and abnormal uterine bleeding have become evident https://www.ctvnews.ca/health/coronavirus/menstrual-changes-to-be-expected-after-covid-19-vaccine-during-pandemic-experts-1.5391236. Since BOMA-USA is a leader in fertility education, we feel it is important that our teachers have information that allows them to answer questions from their clients. It is not our intent to tell you what you should personally do or say to your clients. Everyone must make an individual decision about the risks of COVID-19 and determine if they should put more trust in a vaccination or their own immune system.
How could the vaccine cause cycle aberrations and abnormal bleeding? As trained teachers of the Billings Ovulation Method®, we know that any illness or fever can influence the cycle. This is based on Dr Brown’s description of the continuum, causing cycle variants and bleeding that is not menstruation. On the other hand, there is a possibility that something more than an indirect response to illness or fever is happening.
We know that the spike protein produced by the body after vaccination, is similar to the spike protein on the virus. The function of the spike protein on the virus is to bind to the host cell in our body. It binds to our cells by attaching to a cell membrane protein called ACE-2 on the surface of cells in several types of tissue. Depending on the health status of the person infected, this binding can cause a chain reaction resulting in damage to the tissue (lung, heart, pancreas, etc.). Therefore, it should be suspected that a portion of the same spike protein could function in the same way as the virus itself if it also binds to ACE-2. This paper very elegantly discusses how the virus binds to the host cell, how the vaccines work, and the concern that the spike protein produced after vaccination can activate the same cellular mechanisms as the virus itself https://res.mdpi.com/d_attachment/vaccines/vaccines-09-00036/article_deploy/vaccines-09-00036.pdf
How can this effect uterine bleeding? Well, if the spike protein can bind to cells on the endometrium, like how viral binding affects lung, heart and intestinal tissue, it is reasonable to suspect that it would cause some kind of bleeding disruption. It turns out that the ACE-2 protein, is in fact present on the endometrium https://www.biorxiv.org/content/10.1101/2020.06.23.168252v1. Furthermore, they state that viral binding could impair decidualization, implantation and placentation.
For a very thorough explanation of the importance of proper decidualization of the endometrium to reproductive health, read this fascinating reference https://academic.oup.com/edrv/article/35/6/851/2354669.
Even if the virus or the spike protein produced after vaccination does bind to the endometrium and causes abnormal bleeding, it does not mean that the effect is long-term. There is no proof that either the virus or the vaccine can cause prolonged disruption to the functioning of the endometrium, especially since the uterus grows new cells every cycle. However, this vaccine was produced and implemented very quickly.
There has been limited testing in infants, women desiring pregnancy or pregnant women. Therefore, it has also not been disproven that there could be long-term effects on fertility.
The following statement was just released by the American Society for Reproductive Medicine on 4-20-21:
“Everyone, including pregnant women and those seeking to become pregnant, should get a COVID-19 vaccine. The vaccines are safe and effective.”
This statement and a similar one put out by the American College of Obstetricians and Gynecologists seem to lack the rigorous scientific evidence that has always been required for children and pregnant women. At the very least, there is reason to be skeptical of their motivation for this. Just because a health professional or health authority says it is safe, does not make it so.
Support for the vaccine is based on the belief that the risk of infection and spread of the virus is greater than the risk associated with the vaccine. However, it is important to point out that one does not have to look far into our history to see examples of medicines that were aggressively used only to find out later that they caused harm (i.e. Thalidomide).
Researching the evidence and prayerfully making your own personal decision is the best approach. You can find plenty written to support or not support the current reaction to COVID-19 and it may be difficult to decide. Nevertheless, before making your decision get information from multiple sources and consider the bias that exists in any source.
Below are some additional scientific references related to this topic.:
https://pubmed.ncbi.nlm.nih.gov/32145327/ Demonstrates that Syncytin-1 has a role in placental function and abnormalities that are linked to spontaneous abortion.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7678462/ Syncytin-1 is involved in normal placental function and is associated with implantation of the embryo
Syncytin-1 protein sequences are similar to viral envelops including SARS-CoV https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7092852/
”COVID-19 mRNA vaccines give instructions for our cells to make a harmless piece of what is called the “spike protein”. The spike protein is found on the surface of the virus that causes COVID-19.” https://www.cdc.gov/coronavirus/2019-ncov/vaccines/different-vaccines/mrna.html
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6137383/ Syncytin-1 is a protein that is produced by a retroviral gene that was incorporated into the human genome some time in past human development. It is a gene which is involved in normal placental development but is also linked to pathologies such as neuropsychiatric disorders, autoimmune diseases, and cancer.
I hope you find this useful and feel free to share your own comments.
Craig Turczynski, Ph.D.
Certified Teacher of the Billings Ovulation Method®
Director of Strategy and Scientific Affairs for BOMA-USA
Disclaimer: This information is provided for educational purposes only and is not intended to treat, diagnose or prevent any disease. It is also not intended to replace a relationship with your nurse or physician. We highly recommend learning about your own health and disease prevention so you can take an active role in your healthcare along with a qualified health professional.
BOMA-USA provides education and training for The Billings Ovulation Method® which is a natural method of fertility management that teaches you to recognize the body's natural signs of fertility.