In its emergency authorization of the Pfizer-BioNTech vaccine on Friday night, the Food and Drug Administration took an unexpected step, leaving open the possibility for pregnant and lactating women to opt for immunization against the coronavirus.
The agency licensed the vaccine for anyone 16 years of age or older and asked Pfizer to submit regular reports on the safety of the vaccine, including its use in pregnant women.
There was no guarantee that the agency would take this route. The vaccine was not tested in pregnant or lactating women. Regulators in the UK recommended that these women not receive the injections, acknowledging that the evidence so far “does not raise concerns about safety during pregnancy.”
The Centers for Disease Control and Prevention has yet to endorse the vaccine for pregnant women, but an advisory committee from the agency is expected to meet this weekend to make further recommendations.
Some experts said the virus itself poses greater risks to pregnant women than the new vaccine, noting that the vaccines have been given to pregnant women for decades and have been overwhelmingly safe.
“This is a major step forward in recognizing the empowerment of women to make decisions about their own health care,” said Dr. Emily Miller, obstetrician at Northwestern University and a member of the Society’s COVID-19 task force. for Maternal and Fetal Medication.
With the first doses of the vaccine reserved for healthcare workers and residents of long-term care facilities, the FDA clearance most immediately affects the approximately 330,000 pregnant and lactating healthcare workers in the United States.
“I incredibly support the FDA’s decision to leave the door open to COVID vaccination for pregnant and lactating workers,” said Ruth Faden, a bioethicist at Johns Hopkins University in Baltimore.
Some healthcare workers are at high risk of contracting COVID-19, either because their jobs put them in intense contact with the virus, for example cleaning the rooms of sick patients, or because they live in low-income, multi-generational households. Faden said. .
“We have to be able to give women the opportunity to think about this for themselves with whoever is providing obstetric care,” she said.
Healthcare organizations should also help their employees weigh risks and accommodate women who don’t feel comfortable working on the front lines, he added.
To date, none of the vaccine clinical trials have included pregnant or breastfeeding women, not even women planning to become pregnant; Some trials are expected to begin in January.
Still, the American College of Obstetrics and Gynecology, SMFM, and other organizations have been asking the FDA to allow pregnant and lactating people access to the vaccine.
In a meeting Thursday to review Pfizer’s data for an emergency use authorization, Dr. Doran Fink, the FDA’s deputy director of vaccine development, said the agency was open to the idea.
“We don’t really have data to talk about specific risks to pregnant women or the fetus, but we also don’t have data to justify a contraindication to use in pregnancy at this time,” Fink said. “According to the USA, then they would be free to make their own decisions together with their healthcare provider.”
The USA did not approve the vaccine for pregnant or breastfeeding women, other than noting that Pfizer should collect long-term data on the vaccine’s performance in pregnant women.
Since the 1960s, pregnant women have been urged to receive vaccinations against influenza and other diseases. These women are generally warned against live vaccines, which contain weakened pathogens.
iStockSome women breastfeed for years and, particularly in low- and middle-income countries, not being able to breastfeed can have devastating consequences for babies, experts said.
Still, the benefits of live vaccines outweigh the risks in some situations, said Dr. Denise Jamieson, an obstetrician at Emory University in Atlanta and a member of the ACOG committee on COVID vaccines.
“We have a long history of giving vaccines to pregnant women, and almost all vaccines are very safe,” said Jamieson.
Jamieson said she was “disappointed that the FDA was not more explicit,” but encouraged that “there is no explicit contraindication to pregnancy, which is good.”
Healthcare providers should be prepared to counsel pregnant patients on the decision to vaccinate, based on potential patient exposures and underlying conditions such as diabetes and obesity, Jamieson added.
“A woman who can stay at home, who has no other children and no one at home is working, is very different from an essential worker who needs to go out every day and be surrounded by other people,” she said.
Women who are thinking about becoming pregnant should receive both doses of the vaccine before trying to become pregnant, he added.
In the initial launch, it will be primarily pregnant healthcare workers who will have to weigh the benefits and potential risks. By the time the vaccine is available to pregnant essential workers or women in the general population, there should be much more data available, experts said.
“The big question we don’t know yet is whether it actually crosses the placenta,” said Dr. Geeta Swamy, an obstetrician at Duke University in Durham, North Carolina, and a member of the ACOG COVID vaccine group, referring to the vaccine. . . “To be honest, what would be more reassuring would be to see some of the animal data.”
The so-called DART (developmental and reproductive toxicity) are carried out in animals to evaluate the possible effects of a vaccine on the fetus. Generally, these data are required to license a vaccine, but not for a USA.
Ideally, the animal studies would have been conducted as soon as safety data on the vaccines was available and before companies began large trials, said Faden, the bioethicist. But at the FDA meeting Thursday, Pfizer officials hinted that the animal data would be available by the end of the year.
(Moderna did not respond to inquiries about its schedule for animal studies, and it was unclear whether AstraZeneca and Johnson & Johnson had started theirs.)
“Vaccines that are overdue, if they haven’t started their DART studies, they should start yesterday,” Faden said.
Experts were particularly excited about the possibility that breastfeeding women could get the vaccine. “The biological plausibility that there is any risk of harm to a baby from breastfeeding is extremely, extremely low,” Swamy said.
By the time an antigen, the essential ingredient in the new vaccine, is injected into a woman’s arm to travel through the bloodstream and into breast milk, the antigen disintegrates.
“There is not even a good reason to think that vaccinating children is not safe,” Swamy added. “To be honest, the reason we don’t have pediatric studies yet is because they are trying to determine the correct dose.”
Some women breastfeed for years and, particularly in low- and middle-income countries, not being able to do so can have devastating consequences for babies, experts said.
“I applaud the fact that the FDA has recognized that, in the absence of data and meaning in either direction, decisions must be made between patients and their providers,” Swamy said. “We are talking about women who are adults, right?”