Pregnant & Breastfeeding Women Who Get the COVID-19 Vaccine Are Protecting Their Infants, Research Suggests
Becky Cummings, who got vaccinated in December, snuggles her newborn, Clark, while he takes a nap.
Becky Cummings had multiple reasons to get vaccinated against COVID-19 while tending to her firstborn, Clark, who arrived in September 2020 at 27 weeks.
The 29-year-old intensive care unit nurse in Greensboro, North Carolina, had witnessed the devastation day in and day out as the virus took its toll on the young and old. But when she was offered the vaccine, she hesitated, skeptical of its rapid emergency use authorization.
Exclusion of pregnant and lactating mothers from clinical trials fueled her concerns. Ultimately, though, she concluded the benefits of vaccination outweighed the risks of contracting the potentially deadly virus.
"Long story short," Cummings says, in December "I got vaccinated to protect myself, my family, my patients, and the general public."
At the time, Cummings remained on the fence about breastfeeding, citing a lack of evidence to support its safety after vaccination, so she pumped and stashed breast milk in the freezer. Her son is adjusting to life as a preemie, requiring mother's milk to be thickened with formula, but she's becoming comfortable with the idea of breastfeeding as more research suggests it's safe.
"If I could pop him on the boob," she says, "I would do it in a heartbeat."
Now, a study recently published in the Journal of the American Medical Association found "robust secretion" of specific antibodies in the breast milk of mothers who received a COVID-19 vaccine, indicating a potentially protective effect against infection in their infants.
The presence of antibodies in the breast milk, detectable as early as two weeks after vaccination, lasted for six weeks after the second dose of the Pfizer-BioNTech vaccine.
"We believe antibody secretion into breast milk will persist for much longer than six weeks, but we first wanted to prove any secretion at all after vaccination," says Ilan Youngster, the study's corresponding author and head of pediatric infectious diseases at Shamir Medical Center in Zerifin, Israel.
That's why the research team performed a preliminary analysis at six weeks. "We are still collecting samples from participants and hope to soon be able to comment about the duration of secretion."
As with other respiratory illnesses, such as influenza and pertussis, secretion of antibodies in breast milk confers protection from infection in infants. The researchers expect a similar immune response from the COVID-19 vaccine and are expecting the findings to spur an increase in vaccine acceptance among pregnant and lactating women.
A COVID-19 outbreak struck three families the research team followed in the study, resulting in at least one non-breastfed sibling developing symptomatic infection; however, none of the breastfed babies became ill. "This is obviously not empirical proof," Youngster acknowledges, "but still a nice anecdote."
Leaps.org inquired whether infants who derive antibodies only through breast milk are likely to have a lower immunity than infants whose mothers were vaccinated while they were in utero. In other words, is maternal transmission of antibodies stronger during pregnancy than during breastfeeding, or about the same?
"This is a different kind of transmission," Youngster explains. "When a woman is infected or vaccinated during pregnancy, some antibodies will be transferred through the placenta to the baby's bloodstream and be present for several months." But in the nursing mother, that protection occurs through local action. "We always recommend breastfeeding whenever possible, and, in this case, it might have added benefits."
A study published online in March found COVID-19 vaccination provided pregnant and lactating women with robust immune responses comparable to those experienced by their nonpregnant counterparts. The study, appearing in the American Journal of Obstetrics and Gynecology, documented the presence of vaccine-generated antibodies in umbilical cord blood and breast milk after mothers had been vaccinated.
Natali Aziz, a maternal-fetal medicine specialist at Stanford University School of Medicine, notes that it's too early to draw firm conclusions about the reduction in COVID-19 infection rates among newborns of vaccinated mothers. Citing the two aforementioned research studies, she says it's biologically plausible that antibodies passed through the placenta and breast milk impart protective benefits. While thousands of pregnant and lactating women have been vaccinated against COVID-19, without incurring adverse outcomes, many are still wondering whether it's safe to breastfeed afterward.
It's important to bear in mind that pregnant women may develop more severe COVID-19 complications, which could lead to intubation or admittance to the intensive care unit. "We, in our practice, are supporting pregnant and breastfeeding patients to be vaccinated," says Aziz, who is also director of perinatal infectious diseases at Stanford Children's Health, which has been vaccinating new mothers and other hospitalized patients at discharge since late April.
Earlier in April, Huntington Hospital in Long Island, New York, began offering the COVID-19 vaccine to women after they gave birth. The hospital chose the one-shot Johnson & Johnson vaccine for postpartum patients, so they wouldn't need to return for a second shot while acclimating to life with a newborn, says Mitchell Kramer, chairman of obstetrics and gynecology.
The hospital suspended the program when the Food and Drug Administration and the Centers for Disease Control and Prevention paused use of the J&J vaccine starting April 13, while investigating several reports of dangerous blood clots and low platelet counts among more than 7 million people in the United States who had received that vaccine.
In lifting the pause April 23, the agencies announced the vaccine's fact sheets will bear a warning of the heightened risk for a rare but serious blood clot disorder among women under age 50. As a result, Kramer says, "we will likely not be using the J&J vaccine for our postpartum population."
So, would it make sense to vaccinate infants when one for them eventually becomes available, not just their mothers? "In general, most of the time, infants do not have as good of an immune response to vaccines," says Jonathan Temte, associate dean for public health and community engagement at the University of Wisconsin School of Medicine and Public Health in Madison.
"Many of our vaccines are held until children are six months of age. For example, the influenza vaccine starts at age six months, the measles vaccine typically starts one year of age, as do rubella and mumps. Immune response is typically not very good for viral illnesses in young infants under the age of six months."
So far, the FDA has granted emergency use authorization of the Pfizer-BioNTech vaccine for children as young as 16 years old. The agency is considering data from Pfizer to lower that age limit to 12. Studies are also underway in children under age 12. Meanwhile, data from Moderna on 12-to 17-year-olds and from Pfizer on 12- to 15-year-olds have not been made public. (Pfizer announced at the end of March that its vaccine is 100 percent effective in preventing COVID-19 in the latter age group, and FDA authorization for this population is expected soon.)
"There will be step-wise progression to younger children, with infants and toddlers being the last ones tested," says James Campbell, a pediatric infectious diseases physician and head of maternal and child clinical studies at the University of Maryland School of Medicine Center for Vaccine Development.
"Once the data are analyzed for safety, tolerability, optimal dose and regimen, and immune responses," he adds, "they could be authorized and recommended and made available to American children." The data on younger children are not expected until the end of this year, with regulatory authorization possible in early 2022.
For now, Vonnie Cesar, a family nurse practitioner in Smyrna, Georgia, is aiming to persuade expectant and new mothers to get vaccinated. She has observed that patients in metro Atlanta seem more inclined than their rural counterparts.
To quell some of their skepticism and fears, Cesar, who also teaches nursing students, conceived a visual way to demonstrate the novel mechanism behind the COVID-19 vaccine technology. Holding a palm-size physical therapy ball outfitted with clear-colored push pins, she simulates the spiked protein of the coronavirus. Slime slathered at the gaps permeates areas around the spikes—a process similar to how our antibodies build immunity to the virus.
These conversations often lead hesitant patients to discuss vaccination with their husbands or partners. "The majority of people I'm speaking with," she says, "are coming to the conclusion that this is the right thing for me, this is the common good, and they want to make sure that they're here for their children."
CORRECTION: An earlier version of this article mistakenly stated that the COVID-19 vaccines were granted emergency "approval." They have been granted emergency use authorization, not full FDA approval. We regret the error.
Did researchers finally find a way to lick COVID?
A professor of medicine at the University of Michigan is researching whether lactoferrin, which is found in dairy products such as ice cream, can help to prevent COVID-19 infections.
Already vaccinated and want more protection from COVID-19? A protein found in ice cream could help, some research suggests, though there are a bunch of caveats.
The protein, called lactoferrin, is found in the milk of mammals and thus in dairy products, including ice cream. It has astounding antiviral properties that have been taken for granted and remain largely unexplored because it is a natural product, meaning that it cannot be patented and exploited by pharmaceutical companies.
Still, a few researchers in Europe and elsewhere have sought to better understand the compound.
Jonathan Sexton runs a drug screening program at the University of Michigan where cells are infected with a pathogen and then exposed to a library of the thousands of small molecule drug compounds – which can enter the body more easily than drugs with heavier molecules – approved by the FDA. In addition, the library includes compounds that passed phase 1 safety studies but later proved ineffective against the targeted disease. Each drug is dissolved in a solvent for exposure to the cells in the laborious testing process made feasible by robotic automation.
When COVID hit, researchers scrambled to identify any approved drug that might help fight the infection. Sexton decided to screen the drug library as well as some dietary supplements against SARS-CoV-2, the virus that causes the disease. Sexton says that the grunt work fell to Jesse Wotring, “a very talented PhD student,” who pulled lactoferrin off the shelf. But the regular solvent used in the testing process would destroy the protein, so he had to take another approach and do all the work by hand.
“We were agnostic,” says Sexton, who didn't have a strong interest in lactoferrin or any of the other compounds in the library, but the data was quite clear; lactoferrin “consistently produced the best efficacy...it was the absolute home run.” The findings were published in separate papers last year and in February.
It turns out that lactoferrin has several different mechanisms of action against SARS-CoV-2, inhibiting the virus from entering cells, moving around within them and replicating. Lactoferrin also modulates the overall immune response, which makes it difficult for the virus to simultaneously mutate resistance to the protein at every step of replication. “It has broad efficacy against every [SARS-CoV-2] variant that we've tested,” he says.
From bench to bedside
Sexton's initial interest was to develop a drug for the acute phase of COVID infection, to treat a hospitalized patient or prevent that hospitalization. But with the quick approval of vaccines and drugs to treat the disease, he increasingly focused on ways to better prevent infection and inhibit spread of the virus.
“If you can get lactoferrin to persist in your upper GI tract, then it may very well prevent the primary infection, and that's what we're really interested in.” He reasoned that a chewing gum formula might release enough lactoferrin into the mucosal tissue of the mouth and upper airways to inhibit replication and give the immune system a chance to knock out the virus before it can establish a foothold. It could also reduce the amount of virus spread through talking.
To get enough lactoferrin to have a possible beneficial effect, one would have to drink gallons of milk a day, “and that would have other undesirable consequences, like getting extremely obese,” says Sexton. Obesity is one of the leading risk factors for severe COVID disease.
Testing that theory has been difficult. The easiest way would be a “challenge trial,” where volunteers take the drug, or in this case gum, are exposed to the pathogen, and protection is measured. Some COVID challenge studies have been conducted in Europe but the FDA remains hesitant to allow such a study in the U.S. A traditional prevention study would be like a vaccine trial, involving thousands, perhaps tens of thousands of volunteers over a period of months or years, and it would be very expensive. No one has stepped forward to foot the bill.
So the next step for Sexton is a clinical trial of newly diagnosed COVID patients who will be given standard of care treatment, and layered on top of that they will receive either lactoferrin, probably in pill form, or a placebo. He has identified initial funding. “We would study their viral load over time as well as their symptoms.”
One issue the FDA is grappling with in considering the proposed trial is that it typically decides whether to approve drugs from a factory by applying a rigorous standard, called good manufacturing practices, while food products, which are the source of lactoferrin, are produced under somewhat different standards. The agency still has not finalized rules on how to deal with natural products used as drugs, such as fecal transplants, convalescent plasma, or medical marijuana.
Sexton is frustrated by the delay because lactoferrin derived from bovine milk whey has been used for many decades as a protein supplement by athletes, it is a large component of most infant formula, and the largest number of clinical studies of lactoferrin involve premature infants. There is no question of its safety, he says.
Do it yourself
So what can you do while waiting for regulatory wheels to spin and clinical trial data to be generated?
Could a dose of Ben & Jerry's provide some protection against SARS-CoV-2?
Sexton chuckles at the suggestion. He supposes it couldn't hurt. But to get enough lactoferrin to have a possible beneficial effect, one would have to drink gallons of milk a day, “and that would have other undesirable consequences, like getting extremely obese.” Obesity is one of the leading risk factors for severe COVID disease.
Pseudo-milk products made from soy, almonds, oats, or other plant products do not contain lactoferrin; it has to come from a teat. So that rules them out.
Whey-based protein shakes might be a useful way to add lactoferrin to the diet.
Probably the best option is to take conventional gelatin capsules of lactoferrin that are widely available wherever supplements are sold. Sexton calculates that about a gram a day, four 250 milligram capsules, should do it. He advises two in the morning and two a night. “You really want to take them on an empty stomach...your stomach treats [the lactoferrin protein] like it would a steak” and chops it for absorption in the intestine, which you do not want. About 70 percent of lactoferrin can get through an empty stomach, but eating food cranks up digestive gastric acids and the amount of intact lactoferrin that gets through to the gut plummets.
Sexton cautions, “We have not determined clinical efficacy yet,” and he is not offering advice as a physician, but in the spirit of harm reduction, he realizes that some people are going to try things that might help them. Lactoferrin “is remarkably safe. And so people have to make their own decisions about what they are willing to take and what they are not,” he says.
In today's episode, Leaps.org interviews Camila dos Santos, a molecular biologist at Cold Spring Harbor Lab, about her research on breasts and what makes them unique compared to any other part of the body.
My guest today for the Making Sense of Science podcast is Camila dos Santos, associate professor at Cold Spring Harbor Lab, who is a leading researcher of the inner lives of human mammary glands, more commonly known as breasts. These organs are unlike any other because throughout life they undergo numerous changes, first in puberty, then during pregnancies and lactation periods, and finally at the end of the cycle, when babies are weaned. A complex interplay of hormones governs these processes, in some cases increasing the risk of breast cancer and sometimes lowering it. Witnessing the molecular mechanics behind these processes in humans is not possible, so instead Dos Santos studies organoids—the clumps of breast cells donated by patients who undergo breast reduction surgeries or biopsies.
Show notes:
2:52 In response to hormones that arise during puberty, the breast cells grow and become more specialized, preparing the tissue for making milk.
7:53 How do breast cells know when to produce milk? It’s all governed by chemical messaging in the body. When the baby is born, the brain will release the hormone called oxytocin, which will make the breast cells contract and release the milk.
12:40 Breast resident immune cells are including T-cells and B-cells, but because they live inside the breast tissue their functions differ from the immune cells in other parts of the body,
17:00 With organoids—dimensional clumps of cells that are cultured in a dish—it is possible to visualize and study how these cells produce milk.
21:50 Women who are pregnant later in life are more likely to require medical intervention to breastfeed. Scientists are trying to understand the fundamental reasons why it happens.
26:10 Breast cancer has many risks factors. Generic mutations play a big role. All of us have the BRCA genes, but it is the alternation in the DNA sequence of the BRCA gene that can increase the predisposition to breast cancer. Aging and menopause are the risk factors for breast cancer, and so are pregnancies.
29:22 Women that are pregnant before the age of 20 to 25, have a decreased risk of breast cancer. And the hypothesis here is that during pregnancy breast cells more specialized, as specialized cells, they have a limited lifespan. It's more likely that they die before they turn into cancer.
33:08 Organoids are giving scientists an opportunity to practice personalized medicine. Scientists can test drugs on organoids taken from a patient to identify the most efficient treatment protocol.
Links:
Camila dos Santos’s Lab Page.
Editor's note: In addition to being a regular writer for Leaps.org, Lina Zeldovich is the guest host for today's episode of the Making Sense of Science podcast.
Lina Zeldovich has written about science, medicine and technology for Popular Science, Smithsonian, National Geographic, Scientific American, Reader’s Digest, the New York Times and other major national and international publications. A Columbia J-School alumna, she has won several awards for her stories, including the ASJA Crisis Coverage Award for Covid reporting, and has been a contributing editor at Nautilus Magazine. In 2021, Zeldovich released her first book, The Other Dark Matter, published by the University of Chicago Press, about the science and business of turning waste into wealth and health. You can find her on http://linazeldovich.com/ and @linazeldovich.