The US Food and Drug Administration officially approved the first COVID-19 vaccine for emergency use in mid-December 2020, which cleared the way for a national campaign to inoculate enough Americans to suppress the spread of the coronavirus. But considering that neither the Pfizer-BioNTech vaccine nor the Moderna vaccine that received FDA approval shortly after has been tested on pregnant people or those currently breastfeeding, questions remained as to whether it was safe for those demographic groups to stand in line to receive a vaccine.
"CDC recommends that pregnant people receive the COVID-19 vaccine."
Thankfully, Pfizer announced today that it expected to have clinical trial data on the safety of its vaccine in pregnant women by early August.
Until then, the Centers For Disease Control and Prevention now recommends that pregnant people receive the COVID-19 vaccine, following preliminary results of a new study on the mRNA vaccines. According to the findings, published in The New England Journal of Medicine, data from more than 35,000 pregnant individuals who received the vaccines showed no obvious medical concerns.
"Importantly, no safety concerns were observed for people vaccinated in the third trimester, or safety concerns for their babies," CDC Director Rochelle Walensky said in a briefing on April 23. "As such, CDC recommends that pregnant people receive the COVID-19 vaccine."
This is long-awaited good news for those pregnant or planning to become pregnant.
Why Guidance For Vaccinating Pregnant People Was So Unclear
Up until this point, there has been little clarity as to the best practices for pregnant populations. But why? For starters, nearly as many recommendations have been released as there are public health institutions. Shortly following vaccine approval, the FDA stated that it does not recommend it for pregnant people right now. Meanwhile, the CDC were supportive of vaccinating expectant mothers. And more recently, on Jan. 26, the World Health Organization echoed the FDA's stance: "While pregnancy puts women at a higher risk of severe COVID-19, the use of this vaccine in pregnant women is currently not recommended, unless they are at risk of high exposure."
But just three days later, WHO retracted its previous statement. The organization now says that, based on what is known so far, there is no specific reason to believe the risks would outweigh the benefits of the vaccine for those who are pregnant. WHO added that those at high risk of exposure to COVID, namely health workers, or those who have comorbidities that add to their risk of severe disease, may be vaccinated.
What's more, the FDA has also stated that it is not currently excluding any pregnant individuals from receiving a vaccine.
"This is one where I think you'd want to have, from a provider to an individual, a consideration of the potential benefits and the potential risks — what we don't know about the vaccine versus what we do," said Peter Marks, MD, PhD, the director of the FDA's Center For Biologics Evaluation and Research. "Certainly COVID-19 in a pregnant woman is not a good thing, so someone might decide that they would like to be vaccinated, but that's not something that we're recommending at this time. That's something we're leaving to the individual."
In general, the FDA recommends caution in using any drug or therapy that does not have explicit data on safety in pregnant people. In the case of the COVID-19 vaccine, the United Kingdom has so far advised against vaccinating pregnant people or those who plan to become pregnant within three months of the first dose.
However, many experts argue that just because there is no affirmative data available, it doesn't necessarily mean the vaccine would be harmful for those pregnant or lactating. In fact, pregnant people already routinely receive many vaccines, such as the flu vaccine, the Tdap vaccine, and the hepatitis B vaccine.
"COVID-19 vaccines should not be withheld from women solely based on their pregnancy or lactation status, when they otherwise meet criteria for vaccination."
A panel of experts in maternal-fetal medicine recently made the case that the known risks of infection with COVID-19 during pregnancy outweigh the "unlikely risks of vaccination." The group cited recent studies showing that pregnant women sick with COVID were at a higher risk for needing a ventilator — and for death — than women who were not pregnant. In fact, the CDC noted that although some pregnant women have only mild cases when they contract coronavirus, "data demonstrate potentially increased risks of severe maternal illness and preterm birth due to COVID-19 disease."
Among the panel's recommendations, which were published in the American Journal of Obstetrics and Gynecology, Amanda Craig, MD, wrote, "COVID-19 vaccines should not be withheld from women solely based on their pregnancy or lactation status, when they otherwise meet criteria for vaccination." She said it should be up to them to assess their risk of exposure and make a decision with the advice of their healthcare providers.
It is unclear if the FDA will give further recommendations to pregnant people as more data is collected on Pfizer's and Moderna's vaccines as well as other vaccines finalizing trials, but Stephen Hahn, MD, the FDA commissioner, is confident that their review is thorough. "That level of detail to provide as much information supported by data and science to providers so that they can counsel patients and that patients are aware of the issues is so critically important."
Still, more formal approvals and recommendations are crucial for those first in line to receive a vaccine: namely, healthcare workers. According to the CDC, 75 percent of this workforce is female and roughly 330,000 of them "could be pregnant or recently postpartum at time of vaccine implementation."
Anthony Fauci, MD, the director of the National Institute of Allergy and Infectious Diseases, noted back in December that follow-up vaccine studies that include pregnant women and young children could begin as early as mid- to late January. "That will not necessarily be looking at efficacy, but we'll be looking at safety and immunogenicity to bridge to the efficacy in the adult non-pregnant population," he said in a conference.
He also believes that under a so-called emergency use authorization, pregnant people will very likely not be prohibited from receiving the vaccine. "[They will be] free to make their own decision."