Fact check: Pregnant women do receive vaccines, but more study needed on COVID-19 shot
The claim: Vaccines, COVID-19 included, are not safe during pregnancy
Since their approval for emergency use earlier this month, claims concerning Pfizer and Moderna's coronavirus vaccines have been flying around social media. Among them is one casting skepticism on the vaccine's safety for pregnant women.
"I'm in the Moderna COVID-19 vaccine trial. I specifically asked about my wife who is nursing our son right now. They said the vaccine trial is prohibited from enrolling pregnant or nursing women," reads a Facebook comment shared by naturopath Ben Lynch in a Dec. 20 post.
The comment, from an unknown author and posted as a screenshot, states Moderna does not want female trial participants to try to conceive "within a month of the second injection" or male participants to impregnate women between the first vaccination until a month after the second one. The author does not provide an explanation.
"This means NO VACCINE if PREGNANT or trying to conceive," Lynch writes in a caption with the screenshot. "Stop injecting pregnant women. Stop manipulating them emotionally to feel pressured to vaccinate themselves."
While much of his post is opinion, Lynch does claim "vaccines are not safe during pregnancy," the COVID-19 vaccine even more so since "there's no research on COVID vaccines during pregnancy because it's unethical to do so."
USA TODAY has reached out to Lynch for further comment.
More:Fact check: What's true and what's false about the COVID-19 vaccine
Why are pregnant women excluded from clinical trials?
While the Facebook comment Lynch shared is correct — Moderna has advised male and female trial participants to abstain "from all activities that could result in pregnancy" — the exclusion of pregnant women from clinical research is not atypical.
According to Dr. Heather Byers, a clinical assistant professor in pediatrics at Stanford, women were considered too medically complex, potentially complicating research studies.
"Historically, women in general were excluded from clinical trials because men were thought to be a more homogenous group without hormonal cycles and other sex-based variables that might impact the medical conditions under study," she said in a January 2019 interview with Stanford's Scope.
Despite increased inclusion of women since 1993, when the U.S. Food and Drug Administration reversed its 1977 policy banning women of child-bearing potential, Byers stated exclusion of pregnant women remains persistent.
"In addition, pregnant women are still classified as a 'vulnerable' population for all research studies, so investigators must take additional steps to enroll them to ensure minimum risk. Also, the lack of data about what pregnant women can safely be exposed to leads to more uncertainty. So many investigators choose to exclude them, even if they might benefit from the study intervention," she said.
This vulnerable classification dates back to the 1940s after diethylstilbestrol, or DES, prescribed from the 1940s to 1970s to prevent miscarriage, gave rise to generations of women born with an increased risk for gynecological cancers. Additionally, thalidomide, prescribed in Europe and other countries during the 1950s for morning sickness, was found to cause birth defects, though it was never approved in the U.S. thanks to an FDA pharmacologist, Dr. Frances Oldham Kelsey.
More:Fact check: Thalidomide, COVID-19 vaccine comparisons are misleading
As prevailing as Lynch's opinion that research on pregnant women is "unethical," there has been a paradigm shift since the late 2000s with some ethicists and health care professionals arguing exclusion, instead being protective, is disadvantageous to prenatal care and women's health in general.
"Excluding them is a problem because women don't stop getting sick or stop having chronic medical conditions just because they are pregnant. The average woman is exposed to four medications during her pregnancy and over 80 percent of medications haven't been studied in a like population," said Byers.
Byers stated this "forces pregnant women to take medications on an 'off-label' basis ... because there's no other option."
When it comes to vaccine trials, bioethicists Angela Ballantyne and Françoise Baylis state the exclusion of pregnant women "does not dodge the risk of unproven vaccinations; it simply shifts this risk from a carefully monitored clinical trial to the privacy of a doctor's office."
"Excluding pregnant women from vaccine research is both unjust and imprudent from a public health perspective," they argue in an October article published in The Conversation.
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Pregnant women do receive vaccines
The benefits of maternal vaccination have been recognized since the 19th century, when infants, born to women vaccinated against smallpox during pregnancy, were observed to be protected from the virus during their early life.
It was later understood this temporary protective effect was due to passive immunity. The mother's immune system creates antibodies — molecules that recognize foreign substances like bacteria or viruses — in response to the vaccine. They are passed along to the baby through the placenta, a temporary organ formed during pregnancy that facilitates the transfer of nutrients and wastes between mother and child, or through breast milk.
Maternal vaccination against pertussis, also known as whooping cough, a highly contagious respiratory disease, began in the 1940s, after clinical trials in pregnant women did not appear to have any adverse maternal or fetal outcomes, according to a 2008 CDC report. Influenza vaccination, while not formally tested, was implemented following pandemics of the 1950s. In the 1960s, observational studies and clinical trials found newborn deaths due to tetanus, a potentially fatal infection causing painful muscle spasms, were prevented by vaccinating the mother.
The American College of Obstetricians and Gynecologists continues to recommend with every pregnancy an immunization against pertussis, in the form of a combination vaccine that includes tetanus and diphtheria, a bacterial infection that can cause breathing difficulty and heart failure. Influenza vaccination is recommended seasonally, including during pregnancy if not administered before.
Vaccines that contain a live attenuated virus, like those for measles-mumps-rubella or shingles, are not recommended to pregnant women, according to the CDC. It is theorized the virus, while weakened and less virulent, could be passed on to the fetus through the placenta and cause infection.
All other vaccine forms are generally considered not harmful to the growing baby, according to ACOG.
"There is no evidence of adverse fetal effects from vaccinating pregnant women with inactivated virus, bacterial vaccines, or toxoids, and a growing body of data demonstrate the safety of such use," stated the association in a 2018 committee opinion.
Lynch's statement that vaccines are not safe during pregnancy is misleading, based on this evidence.
More:Fact check: COVID-19 pandemic is not a simulation
What about the COVID-19 vaccine?
While the COVID-19 vaccine does not contain the virus — only some genetic code called mRNA, providing instructions on how to make antibodies against the SARS-CoV-2 spike protein — how it will affect pregnant women is uncertain.
In toxicity studies conducted in pregnant and postpartum rats, the FDA found Moderna's mRNA-based vaccine "did not have any adverse effects on female reproduction, fetal/embryonic development, or postnatal developmental (sic) except for skeletal variations which are common and typically resolve postnatally without intervention."
But animal studies are not always good predictors of human reactions. In an interview with The New York Times, Dr. Michal Elovitz, an obstetrician and preterm labor researcher at the University of Pennsylvania, explained mRNA technology and pregnancy have not been well studied. The mRNA could be completely safe or it could cross the placenta and cause inflammation, potentially harming the fetus.
Dr. Stephanie Gaw, an assistant professor of obstetrics, gynecology and reproductive sciences at the University of California, San Francisco, told Live Science that "it's unlikely that anything meaningful would be able to cross" the placenta, although further studies are needed to confirm.
It is also important to note that because the vaccine is injected into the arm, it is taken up by muscle cells where, after the mRNA serves its use, it is quickly degraded.
"Because it acts locally, it's likely of no consequence to the fetus," said Dr. Denise Jamieson, an OB-GYN and chair of the department of gynecology and obstetrics at Emory University School of Medicine, also to Live Science.
More:Fact check: COVID-19 vaccine 'morally acceptable,' Vatican says but some claims missing context
Doctors and health organizations like ACOG and the Society for Maternal-Fetal Medicine recommend pregnant women have access to the vaccine, given the protective benefits outweigh the considerable risks of coronavirus infection.
According to a November study by the CDC, pregnant women are significantly more likely to be admitted to an intensive care unit, to end up on a ventilator and to die from COVID-19 than women of the same age and health status who are not pregnant. This is likely due to immunological and metabolic changes that permit and accommodate pregnancy but leave mothers-to-be more susceptible to viral infection and subsequently, severe illness.
"I personally feel comfortable recommending to those women that your risk-benefit balance suggests you should get vaccinated," said Dr. Geeta Krishna Swamy, member of ACOG's COVID vaccine group and associate professor of obstetrics and gynecology at Duke University School of Medicine, to USA TODAY.
"If a woman says, 'I don't want to get vaccinated,' I think that's absolutely, positively her choice, just like it's her choice to get vaccinated."
Some vaccine trials in pregnant women are expected to start in January, reports The New York Times.
More:What the COVID-19 vaccine owes to Dr. Jonas Salk and the end of 'polio season'
What about breastfeeding women?
Breastfeeding mothers have also been excluded from Pfizer and Moderna's vaccine trials although, according to the SMFM, "there is no biological plausibility" for their exclusion.
"For some reason that does not make any sense to me, lactating and pregnant women are always lumped into one group," Jamieson said to NPR in December.
"They're actually two very different groups, and there's even less theoretical reason to be concerned about lactating women. We give live viral vaccines — measles, mumps and rubella vaccine — routinely to lactating women."
The Academy of Breastfeeding Medicine also agreed, stating in December that during lactation, "it is unlikely that the vaccine lipid would enter the blood stream and reach breast tissue. If it does, it is even less likely that either the intact nanoparticle or mRNA transfer into milk. In the unlikely event that mRNA is present in milk, it would be expected to be digested by the child and would be unlikely to have any biological effects."
But there is also the possibility the vaccine might even confer benefits to the breastfeeding child through passive immunity, according to the ABM. There appears to be some evidence for this, as one small study found antibodies in the breastmilk of women who recovered from COVID-19.
ACOG, SMFM, ABM and CDC strongly recommend lactating mothers be offered the COVID-19 vaccine, as well as receive professional counseling to weigh individual risks and benefits. ACOG and ABM have also stated there is no need for vaccinated individuals to cease or discontinue breastfeeding following vaccination.
Our ruling: Missing context
We rate the claim that no vaccine is safe during pregnancy or when trying to conceive as MISSING CONTEXT, because without additional context it might be misleading.
While it is true Moderna has recommended vaccine trial participants against conceiving, exclusion of pregnant women is not atypical. Historically, women were considered too medically complex with sex-based variables that could complicate a study. Pregnant women, especially, were classified as a "vulnerable" population following the tragedies of thalidomide and DES. This classification persists, even though clinical trial protocols and drug approval have evolved significantly since then. Some health care advocates, bioethicists and physicians say excluding pregnant women is more harmful than protective, impacting clinical decision making and women's health.
Pregnant women have been receiving vaccines safely since the 1940s and continue to receive vaccination against pertussis, diphtheria, tetanus and influenza. Administering a vaccine with a live virus, thought to possibly pose a risk to the growing fetus, is the only contraindication.
There is little clinical data with which to consider the risk the COVID-19 vaccine poses to pregnancy. Pfizer and Moderna's mRNA-based vaccines are believed to be overall safe with low theoretical risk as the vaccine does not contain a virus itself. Several medical associations call for the vaccine to be available to pregnant women and whether or not it should be administered be based on counseling with a health care professional.
While there is also scarce data when it comes to breastfeeding women, most health experts and medical organizations believe the mRNA-based COVID-19 vaccine poses little to no risk.
Our fact-check sources:
- ClinicalTrials.gov, May 28, "Dose-Confirmation Study to Evaluate the Safety, Reactogenicity, and Immunogenicity of mRNA-1273 COVID-19 Vaccine in Adults Aged 18 Years and Older"
- Scope, Jan. 10, 2019, "On the importance of including pregnant women in clinical trials: A Q&A"
- Pharmacy Practice, Mar. 15, 2016, "Women's involvement in clinical trials: historical perspective and future implications"
- Helix Magazine, July 28, 2009, "The Thalidomide Tragedy: Lessons For Drug Safety and Regulation"
- Smithsonian Magazine, May 8, 2017, "The Woman Who Stood Between America and a Generation of ‘Thalidomide Babies’"
- National Institutes of Health, Oct. 5, 2011 "Women exposed to DES in the womb face increased cancer risk"
- The Conversation, Oct. 14, "Excluding pregnant women from COVID-19 vaccine trials puts their health at risk"
- Centers for Disease Control and Prevention, July 16, "Research on Medicines and Pregnancy"
- Current in Tropical Medicine Reports, Nov. 16, 2019, "Pregnant Women, Vaccine Development for Emerging and Epidemic Viral Infections and Maternal Immunization: Human Rights and the Global Survival of Mothers and Infants"
- Centers for Disease Control and Prevention, May 14, 2008, "Prevention of Pertussis, Tetanus, and Diphtheria Among Pregnant and Postpartum Women and Their Infants: Recommendations of the Advisory Committee on Immunization Practices (ACIP)"
- The Centers for Disease Control and Prevention, March 10, 2017, "Vaccines & Immunity"
- Centers for Disease Control and Prevention, Nov. 18, 2019, "Pertussis (Whopping Cough)"
- Centers for Disease Control and Prevention, accessed Dec. 22, "Tetanus"
- Obstetrics & Gynecology, June 1, 2018, "ACOG Committee Opinion No. 741: Maternal Immunization"
- Centers for Disease Control and Prevention, Aug. 31, 2016, "Guidelines for Vaccinating Pregnant Women"
- American College of Obstetrics and Gynecology, Oct. 27, "Re: Docket No. CDC-2020-0100; Advisory Committee on Immunization Practices; Notice of Meeting; Establishment of a Public Docket; Request for Comments"
- Society for Maternal-Fetal Medicine, Dec. 1, "Society for Maternal-Fetal Medicine (SMFM) Statement: SARS-CoV-2 Vaccination in Pregnancy"
- The Centers for Disease Control and Prevention, Nov. 2, "Update: Characteristics of Symptomatic Women of Reproductive Age with Laboratory-Confirmed SARS-CoV-2 Infection by Pregnancy Status — United States, January 22–October 3, 2020"
- The Conversation, Sept. 16, 2019, "How pregnancy changes women's metabolism and immune systems"
- U.S. Food and Drug Administration, Dec. 17, "Moderna COVID-19 Vaccine: VRBPAC Briefing Document"
- The New York Times, Dec. 22, "I'm a Pregnant Doctor. Should I get the Covid Vaccine?"
- USA TODAY, Dec. 19, "For pregnant and nursing women, risks of COVID-19 probably outweigh risk of vaccine, experts say"
- Live Science, Dec. 22, "Is it safe to get the COVID-19 vaccine if you're pregnant?"
- The New York Times, Dec. 11, "Pregnant and Breastfeeding Women May Opt to Receive the Vaccine"
- Centers for Disease Control and Prevention, Oct. 30, "ACIP COVID-19 Vaccines: Work Group interpretations of data"
- NPR, Dec. 11, "Pregnant People Haven't Been Part Of Vaccine Trials. Should They Get The Vaccine?"
- Academy of Breastfeeding Medicine, Dec. 14, "Considerations for COVID-19 Vaccination in Lactation"
- American College of Obstetrics and Gynecology, Dec. 21, "Vaccinating Pregnant and Lactating Patients Against COVID-19"
- The Scientist, Nov. 17, "Breastmilk Harbors Antibodies to SARS-CoV-2"
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