The confusion is understandable: Early clinical trials of Pfizer/BioNTech and Moderna’s coronavirus vaccines failed to include pregnant and lactating women, so safety data is not available for these populations. But the valid concerns about this information void have been eclipsed by targeted misinformation campaigns led by vaccine skeptics who are weaponizing women’s health issues to advance their agenda. These falsehoods are being spread to amplify our legitimate anxieties and undermine trust in vaccination.
We empathize with the fear stemming from a lack of data. Many women are being bombarded with social media posts that falsely claim that coronavirus vaccines cause infertility. They do not want to take chances. These women need reassurance of the benefits of getting vaccinated, and they need clear explanations of why declining the vaccine would be a bigger gamble.
One myth claims that the vaccines cause infertility by generating antibodies that not only target the coronavirus spike protein, as designed, but also inadvertently react with a protein in the placenta called syncytin-1. Supposedly, the viral protein and human protein are so similar in structure that the protective antibodies against the coronavirus will also prevent the placenta from developing properly, causing infertility.
This is completely false.
Our team compared the coronavirus’s spike protein to placental syncytin-1, and we found no notable similarity between their amino acid sequences. We analyzed serum from women with Covid-19 and did not detect any reaction between patients’ antibodies and the syncytin-1 protein. There is also no evidence or reports so far of infertility among women who have recovered from Covid-19, despite the millions who have been infected. To the contrary, women have conceived after coronavirus infection and vaccination. They include vaccinated women who became pregnant while participating in clinical trials of the vaccines. It is exceedingly unlikely that vaccine materials representing a small portion of the virus would impair fertility.
With little data and weak public messaging on coronavirus immunization during breastfeeding, women have been left to draw their own conclusions and are naturally assuming the worst. But the immunization of lactating women is practically guaranteed to benefit both mother and baby. After all, vaccines induce protective immune responses in the mother, creating antibodies that are passed to infants via breast milk and serve to protect them. And it is unlikely that the vaccine can cross into breast milk. Even if they did, they would not pose a threat to the health of a nursing baby; if ingested, these components would be digested and degraded in the gastrointestinal tract. Neither mother nor infant is at any risk for coronavirus infection from the vaccines.
The decision to get vaccinated for the coronavirus during pregnancy asks women to assess their own risk. If a pregnant woman is not in any danger of being exposed to the virus, then it may make sense for her to wait to vaccinate until the baby is born or until more data is available. But the decision may be very different for essential workers who are at much higher risk of exposure.
Any immune response during pregnancy, whether from an infection or a vaccine, could have unknown consequences. However, studies of coronavirus vaccination in animals have shown no impact on pregnancy, and human studies are in the works. Of course, vaccines for the flu and for tetanus, diphtheria and pertussis are routinely and safely administered to pregnant women.
While we do not yet know everything about Covid-19 in human pregnancy, we do know that pregnant women who contract the disease are at higher risk for severe illness. The infection may also be associated with potentially life-threatening complications of pregnancy, such as pre-eclampsia, a condition characterized in part by dangerously high maternal blood pressure. In rare cases, the coronavirus can invade the placenta.
In contrast, there is zero chance that someone can get Covid-19 disease from the vaccines, which contain no live virus. We worry that women who hesitate to get immunized are underestimating the risk of Covid-19 and overestimating the risk of the vaccines.
Unfortunately, women are absorbing rumors much more quickly than they are getting answers from scientists. If vaccine hesitancy leads to deeper mistrust of the medical establishment, there will be no way to convince those we most need to protect, even once more data is available. The scientific community needs to demonstrate that we are listening to and addressing the public’s concerns. Women will of course make their own decisions, but they cannot do so in an informed way without knowing the true risks and benefits of vaccination.
For any woman who is pregnant, nursing or trying to conceive, contracting Covid-19 is almost certainly more dangerous than getting immunized. And ultimately, mass vaccination, combined with physical distancing and wearing masks, provides the only way that we can end the pandemic and protect all women, men and children from the disease.