The Pfizer and Moderna vaccines are the fastest and safest vaccines in the history of vaccinology created without cutting corners and approved by the FDA. Why, then, are so many people afraid of getting vaccinated? Why are women of child-bearing age afraid that the vaccine that will protect them from a potentially miserable, if not deadly virus, will destroy their fertility?
Many vaccine-refusers have expressed hesitancy in light of the speed with which these were created. However, a combination of factors contributed to this unprecedented achievement, including several layers of reviews by panels of distinguished scientists independent of government and industry. Yet the new face of COVID-19 vaccine refusal is that of a young woman, aged 18-34, afraid that the vaccine causes infertility.
The concern started on social media and went viral, gripping all segments of society. But are these fears legitimate? Here is what we know about the COVID-19 vaccines and infertility.
In contrast to vaccines that use a weakened or inactivated virus to trigger an immune response, the Pfizer and Moderna COVID-19 vaccines use mRNA, which instructs our cells to produce the spike protein that lies on the surface of the coronavirus. Once the cells produce the protein, they destroy the mRNA. The cell displays the spike protein on its surface. Our immune systems, which recognize that the spike protein does not belong there, begin to create antibodies to fight the spike protein — and also protect our body from future infection, by recognizing that same spike in the coronavirus itself. Note that the mRNA does not enter the nucleus of the cell (which is where our DNA is found) or interact with our DNA in any way.
The Effect of COVID-19 Vaccine on Fertility and Pregnancy
Although neither Pfizer nor Moderna enrolled pregnant women in their phase III trials and there is currently insufficient data for pregnant women, scientists anticipate that the safety and efficacy of the vaccine in pregnant women will be comparable to those who are not pregnant — based on the way that this type of vaccine works. Because these vaccines do not use a live virus, experts believe that they are unlikely to cause infertility or congenital anomalies.
Indeed, during phase III trials, 23 of the women enrolled in the study became pregnant after joining the study. To date, not one had adverse effects (one woman in the control group, who did not receive the vaccine and also did not have COVID-19, suffered a spontaneous pregnancy loss). Of course, a pregnant woman should always consult with her own physician before proceeding to get vaccinated.
Claims that the vaccine might cause female sterility arose due to a slight similarity between the spike protein, used to fight COVID-19, and syncytin-1, a protein that promotes placental development — as if the immune system that fights the spike protein would misidentify the placental development protein. Thankfully, the worry turns out to be misplaced, as the similarity between the two proteins is too minor for the immune system to confuse them. Thus, the immune system that has been trained, as it were, to attack the spike protein is not at risk of attacking the placenta, and the vaccine would not jeopardize a woman’s ability to carry a pregnancy to term.
Support for this conclusion is in the numbers of pregnant COVID-19 patients themselves. Between January 22, 2020 and January 11, 2021, the CDC has reported a total of 55,154 pregnant women with COVID-19 at some point in their pregnancies. If the placenta were in danger from antibodies that attack the spike protein, then the women who had COVID-19 while pregnant, and therefore had those same antibodies while pregnant, would have seen an increase in placental issues as a result of those attacks. But that did not happen; the scientists have seen no such effect. To the contrary: it is COVID-19 itself and its onslaught on the body that has resulted in pregnancy complications, including pre-term deliveries — as well as the deaths of 66 of the women.
At this time, trials testing the vaccines in pregnant women are being designed. In the meantime, Moderna has released data from Developmental and Reproductive Toxicity (DART) studies in rats that show no adverse effects of the vaccine when it was administered prior to mating or during gestation. Pfizer has not yet announced comparable data, but has preliminarily confirmed that it has found no major safety issues.
The Effect of COVID-19 on Pregnancy
Pregnant women have been advised to take great caution to avoid COVID-19 exposure. Especially because both COVID-19 and pregnancy (particularly in the third trimester) put pressure on the lungs, the combination can be dangerous. Bodily changes during pregnancy decrease lung capacity, and any viral infection that affects the lungs can make it extremely difficult for a pregnant woman to breathe. Pregnant women with COVID-19 symptoms have a higher risk of severe illness, admission to the ICU, cardiopulmonary support, and even death, as compared to non-pregnant symptomatic women. For this reason, the CDC lists pregnancy among the high-risk criteria for COVID-19. The American College of Obstetrics and Gynecology as well as the Society for Maternal-Fetal Medicine therefore recommend that “the vaccine not be withheld from pregnant women who meet the Advisory Committee on Immunization Practices (ACIP) requirement for vaccination among their priority group.” ACOG strongly recommends vaccination for women contemplating pregnancy, as a benefit that will increase the likelihood of a healthy pregnancy. That is, the risks of COVID-19 on pregnancy outweigh any concerns regarding vaccine safety. Moreover, one need not delay pregnancy after vaccination, or interrupt fertility treatment to be able to be vaccinated.
Moreover, ACOG also recommends offering the vaccine to nursing women — and women do not need to stop breastfeeding if they want to get a vaccine. The protection the vaccine offers against the potentially dangerous virus far outweighs the theoretical risks of the vaccine.
A healthy pregnancy is one of the most important steps a woman can take to insure a healthy baby. Over 800 years ago, Maimonides wrote, “It is a positive mitzvah to remove any obstacle that could pose a danger to life, and to be very careful regarding these matters, as Deuteronomy 4:9 states: “Beware for yourself; and guard your soul.” If a person leaves a dangerous obstacle and does not remove it, he negates the observance of a positive commandment, and violates the negative commandment: “Do not cause blood to be spilled” (Hilchot Rotzeach U’shmirat Haguf 11:4). COVID-19 is certainly a dangerous obstacle for pregnancy, increasing the risk of an adverse outcome. Removing that obstacle through vaccination prior to pregnancy would appear to fulfill two positive commandments, and failure to do so appears to violate one negative commandment.
Those who have concerns regarding the safety of the COVID-19 vaccine should speak to their physicians. But based on all the data, the risk of COVID-19 and its potentially devastating effects on maternal health during pregnancy, potential for preterm birth far outweigh any theoretical, unfounded concerns regarding the vaccine. For those contemplating pregnancy, there is no reason to delay vaccination. Women who are trying to get pregnant take many steps to promote the health of their future children. Vaccinating against COVID-19 simply joins the list that includes taking prenatal vitamins and avoiding cigarettes and alcohol. And for those who have been offered the COVID-19 vaccine, our advice is to add it to the list of precautions and preventions that pertain to all eligible women who are currently pregnant or might be so in the future.
The above was co-authored by Dr. Amy Kesselman, who is a gynecologist with over 20 years of experience in women’s health. She is a graduate of Columbia College and Albert Einstein Medical School, and is in private practice in Israel.