COVID; Your Pregnancy Matters

Should pregnant or breastfeeding women take the COVID-19 vaccine?

Dr. Austin Dennard said she felt comfortable receiving the COVID-19 vaccine based on the fundamental principles of how MRNA vaccines work to develop viral immunity. "As a physician and a mother, receiving the vaccine is another opportunity I have to fight for the health of my patients, my community, and my pregnancy."

Since the beginning of the COVID-19 pandemic, pregnant patients have been advised to be especially vigilant about safety precautions: wash your hands, social distance, avoid large gatherings, and wear a face covering.

Now, nearly a year later, the U.S. is delivering its first shipments of vaccines and several other formulations are in various stages of investigation and approval. New information flows daily from the U.S. Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), and the Advisory Committee on Immunization Practices (ACIP).

However, a major question remains mostly unanswered: Is the vaccine safe for women who are pregnant or breastfeeding?

Pregnant and breastfeeding patients were not included in the first round of clinical trials for the novel coronavirus vaccination, despite consistent advocacy from national organizations such as the Society for Maternal-Fetal Medicine (SMFM) and National Academy of Medicine.

On Dec. 11, the FDA panel that authorized the Pfizer/BioNTech vaccine for emergency use debated the topic of pregnancy and the vaccine. Among the points discussed was the fact that at least 330,000 of the country’s 21 million health care workers included in the first wave of vaccine recipients are expected to be pregnant or breastfeeding.

Vaccines manufactured by Pfizer and Moderna have demonstrated early efficacy in recently published peer-reviewed results. Both use genetic technology that activates antibody production against the spike protein on the virus, which blocks entry of the virus into cells and prevents COVID disease.

We recommend that patients discuss vaccine options with their obstetric care provider. Things to consider are whether you have any other medical conditions that make a COVID-19 infection more dangerous for you, how compliant you can be with the precautions that reduce the risk of infection, and how prevalent COVID-19 infections are in your community.

In a Dec. 1, 2020, statement, SMFM recommended that pregnant healthcare workers be offered the vaccination. The American College of Obstetricians and Gynecologists (ACOG) agreed in its Dec. 12, 2020 guidelines. Additionally, ACIP advised that pregnant women in prioritized groups may choose to get Pfizer’s COVID-19 vaccine, which is the first to be authorized for emergency use in the United States.

Healthcare workers and residents in long-term care facilities around the country will be included in the initial offering of the vaccine. UT Southwestern began delivering the vaccinations to some frontline employees on Dec. 15. Austin Dennard, D.O., a member of our Ob/Gyn team at UT Southwestern, said she was eager to get vaccinated that first day.

"While pregnant and lactating women were not involved in the COVID-19 vaccine trials, I felt comfortable receiving the vaccine based on the fundamental principles of how mRNA vaccines work to develop viral immunity," she said. "As a physician and a mother, receiving the vaccine is another opportunity I have to fight for the health of my patients, my community, and my pregnancy. I look forward to holding this baby in my arms with the confidence that I have done everything in my power to create a healthier safer world for their future."

Other essential workers and pregnant patients with risk factors for COVID-19 complications, such as asthma, diabetes, or obesity, are growing anxious about whether they'll be offered a COVID-19 vaccine – or whether to take it. We are hearing from them every day, so we compiled this list of questions, along with our answers based on what we know about the vaccines right now. We will continue to provide up-to-date information about your pregnancy care.

1. How does the vaccine work?

Unlike many vaccines, there is no live or weakened virus in the first two COVID-19 vaccines likely to be available. The Pfizer and Moderna vaccines, which both require two shots, are gene-based injections that consist of messenger material called RNA from the virus that is surrounded by lipid nanoparticles. Once introduced into your body, that synthetic material allows your body to develop an immune response, which is protective if you are exposed to the real COVID-19 virus. Messenger RNA does not change your DNA and the RNA is degraded quickly once it sends this message to your immune system.

Because there is no live or weakened virus in the COVID-19 vaccine, you cannot become infected from the vaccination itself. Vaccines that do include live or weakened virus, such as the measles, mumps, and rubella (MMR) vaccine or the intranasal flu vaccine, are not given during pregnancy.

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2. Are the vaccines effective?

Manufacturers judge efficacy by comparing how many cases of COVID-19 infection occurred in the vaccinated group compared to the unvaccinated (placebo) group in a clinical trial.

Pfizer is reporting 95% efficacy. In the Pfizer trial of about 44,000 participants, 170 people were infected with COVID-19, 95% of whom were in the placebo group. Moderna is reporting 94.5% efficacy with about 30,000 participants in its clinical trial.

While pregnant women were not included in Pfizer’s vaccine trials, about two dozen participants became pregnant during the studies. None reported complications from the vaccine.

Overall, it appears the vaccinations are effective in preventing symptomatic COVID-19 disease. It’s not clear yet whether the vaccines will be able to prevent you from getting an asymptomatic infection or spreading the virus silently to others. Therefore, handwashing, social distancing, and masking are still critically important for now.

The CDC says there is no need to avoid breastfeeding if you receive a COVID-19 vaccine, and data from previous vaccines suggest mothers can pass protective antibodies to their babies through breastmilk.

3. Will the vaccination protect my baby?

Maternal vaccination during late pregnancy can help protect a newborn from potentially deadly infections. During pregnancy, the mother's body forms antibodies against diseases such as influenza or whooping cough that pass to the fetus, giving babies some protection before they are old enough to be vaccinated.

Breastfeeding mothers can also pass antibodies through breastmilk. Though we do not yet have data specific to COVID-19 and maternal vaccination, information from other respiratory disease vaccinations suggests newborn protection is likely. Since mRNA vaccines do not contain infectious viral material, the CDC feels that mRNA vaccines do not pose a risk to breastmilk-fed infants. There is no need to avoid breastfeeding if you receive a COVID-19 vaccine, both after the first and second doses.

4. Will the vaccine affect fertility in women?

There is no evidence or reason to think COVID-19 vaccines affect fertility, despite some claims to the contrary circulating on the internet. Those reports are rooted in the theory that because the SARS-CoV-2 spike protein resembles the syncytin-1 protein, which is crucial for formation of the placenta, the COVID-19 vaccines might prompt an immune response that targets the placenta protein. But virologists say the two proteins are completely unrelated and not similar enough to confuse antibodies that attack the virus.

5. What are the side effects of the immunization?

In the Pfizer trial, the most commonly reported side effects were mild and included fatigue, headache, and muscle aches. Less frequent were fever and chills. Pain or redness at the injection site may also occur, as with any injection. Side effects were more common in younger participants and following the second dose.

The CDC is not recommending taking fever-lowering or anti-inflammatory medications prior to receiving your injection. Instead, pregnant patients may take acetaminophen if they notice these symptoms after vaccination.

Please note: Experiencing side effects does not mean you are infected with COVID-19. It means your body is responding appropriately to the immunization.

Vaccine Pfizer/BioNTech Moderna
Technology mRNA mRNA
Phase 3 trial participants 44,000 30,000
Efficacy rate 95% 94.5%
Doses needed 2, 21 days apart 2, 28 days apart
Status Authorized by FDA Authorized by FDA

6. Why do I need two shots?

The efficacy of a single dose of the vaccine was not studied systematically, so recipients should take both doses to trigger the full immune response necessary for protection. It’s not uncommon for vaccinations to require two doses, a first shot that primes the immune system and a “booster” shot that strengthens the immune response.

The timing of the two shots varies depending on which type of vaccine your provider administers, and the two vaccines are not interchangeable. Pfizer's should be given three weeks apart, and Moderna's should be given four weeks apart. Providers will work with you to schedule both appointments and set up multiple reminders when it’s time to receive the second shot.

7. How soon am I protected after the first dose?

FDA data show that Pfizer's vaccine may offer up to 82% efficacy between the first and second injections, and that Moderna's vaccine may offer as much as 80.2% efficacy within 14 days after the first injection, though more information will be needed to determine whether this protection is long-term. Data for neither vaccine support limiting patients to just one dose – two doses are recommended to achieve 95% protection about a week after the second shot.

Remember: Getting the COVID-19 immunization does not mean you can stop the now-normal infection prevention standards of handwashing, social distancing, and masking. You should also continue to avoid large, indoor gatherings.

As with any vaccination, immunity is not 100%. And we don’t know yet if immunized patients can still spread the infection to others. Getting large portions of the population vaccinated will move the country closer to herd immunity and, ultimately, an end to the pandemic.

8. Who should not get the vaccine?

The first batch of Pfizer/BioNTech vaccine vials began arriving at hospitals in Texas the week of Dec. 14.

The Pfizer vaccine is recommended for patients age 16 and up. Younger children and pregnant women were not included in the first clinical trials, but they will be as the studies continue to expand.

The vaccine only contains mRNA and the lipid nanoparticles. If you have had the life-threatening response anaphylaxis to previous injections or immunizations, you should not receive the vaccination until you have talked with your doctor. It is possible the ingredient that triggered your response is part of this vaccine. There are no preservatives in the Pfizer vaccine. People who have more common allergies to foods, pollen, or medications taken by mouth are still eligible to receive the Pfizer vaccine.

The CDC also recently recommended that patients who have received treatment with monoclonal antibodies should wait 90 days before getting vaccinated.

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Stay tuned for more safety updates

COVID-19 vaccination during pregnancy will be an evolving conversation. Over the next few weeks, more information and guidance will be released about the safety, effectiveness, and availability of vaccination options, and we expect different types of vaccines to become available in the future.

For now, pregnant and breastfeeding women, as well as those considering pregnancy, should discuss the vaccine with their Ob/Gyn provider. Some factors we will encourage you to consider are the level of COVID-19 spread in your community, whether you have any medical conditions that elevate your risk of COVID-19 complications, and how comfortable you are taking the vaccine. It’s worth noting that pregnant women have been receiving vaccines for decades and they have been overwhelmingly safe.

Your health, safety, and well-being are our priorities, and we will help you make the best decision for your family.

To visit with an Ob/Gyn, call 214-645-8300 or request an appointment online.