May 03 | 2021
Pregnant & Breastfeeding Women Who Get the COVID-19 Vaccine Are Protecting Their Infants, Research Suggests
Susan Kreimer is a New York-based freelance journalist who has followed the landscape of health care since the late 1990s, initially as a staff reporter for major daily newspapers. She writes about breakthrough studies, personal health, and the business of clinical practice. Raised in the Chicago area, she holds a B.A. in Journalism/Mass Communication and French, with minors in German and Russian, from the University of Iowa and an M.S. from the Columbia University Graduate School of Journalism.
Becky Cummings, who got vaccinated in December, snuggles her newborn, Clark, while he takes a nap.
Photo credit: Rachel Walter
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.
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Susan Kreimer is a New York-based freelance journalist who has followed the landscape of health care since the late 1990s, initially as a staff reporter for major daily newspapers. She writes about breakthrough studies, personal health, and the business of clinical practice. Raised in the Chicago area, she holds a B.A. in Journalism/Mass Communication and French, with minors in German and Russian, from the University of Iowa and an M.S. from the Columbia University Graduate School of Journalism.
September 03 | 2021
Sept. 13th Event: Delta, Vaccines, and Breakthrough Infections
A visualization of the virus that causes COVID-19.
Photo by Fusion Medical Animation on Unsplash
This virtual event will convene leading scientific and medical experts to address the public's questions and concerns about COVID-19 vaccines, Delta, and breakthrough infections. Audience Q&A will follow the panel discussion. Your questions can be submitted in advance at the registration link.
DATE:
Monday, September 13th, 2021
12:30 p.m. - 1:45 p.m. EDT
REGISTER:
Dr. Amesh Adalja, M.D., FIDSA, Senior Scholar, Johns Hopkins Center for Health Security; Adjunct Assistant Professor, Johns Hopkins Bloomberg School of Public Health; Affiliate of the Johns Hopkins Center for Global Health. His work is focused on emerging infectious disease, pandemic preparedness, and biosecurity.
Dr. Nahid Bhadelia, M.D., MALD, Founding Director, Boston University Center for Emerging Infectious Diseases Policy and Research (CEID); Associate Director, National Emerging Infectious Diseases Laboratories (NEIDL), Boston University; Associate Professor, Section of Infectious Diseases, Boston University School of Medicine. She is an internationally recognized leader in highly communicable and emerging infectious diseases (EIDs) with clinical, field, academic, and policy experience in pandemic preparedness.
Dr. Akiko Iwasaki, Ph.D., Waldemar Von Zedtwitz Professor of Immunobiology and Molecular, Cellular and Developmental Biology and Professor of Epidemiology (Microbial Diseases), Yale School of Medicine; Investigator, Howard Hughes Medical Institute. Her laboratory researches how innate recognition of viral infections lead to the generation of adaptive immunity, and how adaptive immunity mediates protection against subsequent viral challenge.
Dr. Marion Pepper, Ph.D., Associate Professor, Department of Immunology, University of Washington. Her lab studies how cells of the adaptive immune system, called CD4+ T cells and B cells, form immunological memory by visualizing their differentiation, retention, and function.
This event is the third of a four-part series co-hosted by Leaps.org, the Aspen Institute Science & Society Program, and the Sabin–Aspen Vaccine Science & Policy Group, with generous support from the Gordon and Betty Moore Foundation and the Howard Hughes Medical Institute.
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Kira Peikoff was the editor-in-chief of Leaps.org from 2017 to 2021. As a journalist, her work has appeared in The New York Times, Newsweek, Nautilus, Popular Mechanics, The New York Academy of Sciences, and other outlets. She is also the author of four suspense novels that explore controversial issues arising from scientific innovation: Living Proof, No Time to Die, Die Again Tomorrow, and Mother Knows Best. Peikoff holds a B.A. in Journalism from New York University and an M.S. in Bioethics from Columbia University. She lives in New Jersey with her husband and two young sons. Follow her on Twitter @KiraPeikoff.
September 02 | 2021
Don't Panic Over Waning Antibodies. Here's Why.
A health care worker places a bandaid on the arm of a man who has just been vaccinated.
Since the Delta variant became predominant in the United States on July 7, both scientists and the media alike have been full of mixed messages ("breakthrough infections rare"; "breakthrough infections common"; "vaccines still work"; "vaccines losing their effectiveness") but – if we remember our infectious diseases history- one thing remains clear: immunity is the only way to get through a pandemic.
What Happened in the Past
The 1918 influenza pandemic was far the deadliest respiratory virus pandemic recorded in recent human history with over 50 million deaths (maybe even 100 million deaths, or 3% of the world's population) worldwide. Although they used some of the same measures we are using now (masks, distancing, event closures, as neither testing nor a vaccine existed back then), the deaths slowed only after enough of the population had either acquired immunity through natural infection or died. Indeed, the first influenza vaccine was not developed until 1942, more than 20 years later. As judged by the amount of suffering and death from 1918 influenza (and the deadly Delta surge in India in spring 2021), natural immunity is obviously a terrible way to get through a pandemic.
Similarly, measles was a highly transmissible respiratory virus that led to high levels of immunity among adults who were invariably exposed as children. However, measles led to deaths each year among the nonimmune until a vaccine was developed in 1963, largely restricting current measles outbreaks in the U.S. now to populations who decline to vaccinate. Smallpox also led to high levels of immunity through natural infection, which was often fatal. That's why unleashing smallpox on a largely nonimmune population in the New World was so deadly. Only an effective vaccine – and its administration worldwide, including among populations who declined smallpox vaccine at first via mandates – could control and then eventually eradicate smallpox from Earth.
Fully vaccinated people are already now able to generate some antibodies against all the variants we know of to date, thanks to their bank of memory B cells.
The Delta variant is extremely transmissible, making it unlikely we will ever eliminate or eradicate SARS-CoV-2. Even Australia, which had tried to maintain a COVID-zero nation with masks, distancing, lockdowns, testing and contact tracing before and during the vaccines, ended a strategy aimed at eliminating COVID-19 this week. But, luckily, since highly effective and safe vaccines were developed for COVID-19 less than a year after its advent on a nonimmune population and since vaccines are retaining their effectiveness against severe disease, we have a safe way out of the misery of this pandemic: more and more immunity. "Defanging" SARS-CoV-2 and stripping it of its ability to cause severe disease through immunity will relegate it to the fate of the other four circulating cold-causing coronaviruses, an inconvenience but not a world-stopper.
Immunity Is More Than Antibodies
When we say immunity, we have to be clear that we are talking about cellular immunity and immune memory, not only antibodies. This is a key point. Neutralizing antibodies, which prevent the virus from entering our cells, are generated by the vaccines. But those antibodies will necessarily wane over time since we cannot keep antibodies from every infection and vaccine we have ever seen in the bloodstream (or our blood would be thick as paste!). Vaccines with shorter intervals between doses (like Pfizer vaccines given 3 weeks apart) are likely to have their antibodies wane sooner than vaccines with longer intervals between doses (like Moderna), making mild symptomatic breakthroughs less likely with the Moderna vaccine than the Pfizer during our Delta surge, as a recent Mayo Clinic study showed.
Luckily, the vaccines generate B cells that get relegated to our memory banks and these memory B cells are able to produce high levels of antibodies to fight the virus if they see it again. Amazingly, these memory B cells will actually produce antibodies adapted against the COVID variants if they see a variant in the future, rather than the original antibodies directed against the ancestral strain. This is because memory B cells serve as a blueprint to make antibodies, like the blueprint of a house. If a house needs an extra column (or antibodies need to evolve to work against variants), the blueprint will oblige just as memory B cells will!
One problem with giving a 3rd dose of our current vaccines is that those antibodies won't be adapted towards the variants. Fully vaccinated people are already now able to generate some antibodies against all the variants we know of to date, thanks to their bank of memory B cells. In other words, no variant has evolved to date that completely evades our vaccines. Memory B cells, once generated by either natural infection or vaccination, should be long-lasting.
If memory B cells are formed by a vaccine, they should be as long-lasting as those from natural infection per various human studies. A 2008 Nature study found that survivors of the 1918 influenza pandemic were able to produce antibodies from memory B cells when exposed to the same influenza strain nine decades later. Of note, mild infections (such as the common cold from the cold-causing coronaviruses called 229E, NL63, OC43, and HKU1) may not reliably produce memory B cell immunity like more severe infections caused by SARS-CoV-2.
Right about now, you may be worrying about a super-variant that might yet emerge to evade all our hard-won immune responses. But most immunologists do not think this is very realistic because of T cells. How are T cells different from B Cells? While B cells are like the memory banks to produce antibodies when needed (helped by T cells), T cells will specifically amplify in response to a piece of the virus and help recruit cells to attack the pathogen directly. We likely have T cells to thank for the vaccine's incredible durability in protecting us against severe disease. Data from La Jolla Immunology Institute and UCSF show that the T cell response from the Pfizer vaccine is strong across all the variants.
Think of your spike protein as being comprised of 100 houses with a T cell there to cover each house (to protect you against severe disease). The variants have around 13 mutations along the spike protein so 13 of those T cells won't work, but there are over 80 T cells remaining to protect your "houses" or your body against severe disease.
Although these are theoretical numbers and we don't know exactly the number of T cell antigens (or "epitopes") across the spike protein, one review showed 1400 across the whole virus, with many of those in the spike protein. Another study showed that there were 87 epitopes across the spike protein to which T cells respond, and mutations in one of the variants (beta) took those down to 75. The virus cannot mutate indefinitely in its spike protein and still retain function. This is why it is unlikely we will get a variant that will evade the in-breadth, robust response of our T cells.
Where We Go From Here
So, what does this mean for getting through this pandemic? Immunity and more immunity. For those of us who are vaccinated, if we get exposed to the Delta variant, it will boost our immune response although the memory B cells might take 3-5 days to make new antibodies, which can leave us susceptible to a mild breakthrough infection. That's part of the reason the CDC put back masks for the vaccinated in late July. For those who are unvaccinated, immunity will be gained from Delta but often through terrible ways like severe disease.
The way for the U.S. to determine the need for 3rd shots among those who are not obviously immunocompromised, given the amazing immune memory generated by the vaccines among immunocompetent individuals, is to analyze the cases of the ~6000 individuals who have had severe breakthrough infections among the 171 million Americans fully vaccinated. Define their co-morbidities and age ranges, and boost those susceptible to severe infections (examples could include older people, those with co-morbidities, health care workers, and residents of long-term care facilities). This is an approach likely to be taken by the CDC's Advisory Committee on Immunization Practices.
If immunity is the only way to get through the pandemic and if variants are caused mostly by large populations being unvaccinated, there is not only a moral and ethical imperative but a practical imperative to vaccinate the world in order to keep us all safe. Immunocompetent Americans can boost their antibodies, which may enhance their ability to avoid mild breakthrough infections, but the initial shots still work well against the most important outcomes: hospitalizations and deaths.
There has been no randomized, controlled trial to assess whether three shots vs. two shots meaningfully improve those outcomes. While we ought to trust immune memory to get the immunocompetent in the United States through, we can hasten the end of this pandemic by providing surplus vaccines to poor countries to combat severe disease. Doing so would not only revitalize the role of the U.S. as a global health leader – it would save countless lives.
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Monica Gandhi MD, MPH is a Professor of Medicine and Associate Chief in the Division of HIV, Infectious Diseases, and Global Medicine at the University of California, San Francisco (UCSF). She is also the Director of the UCSF Center for AIDS Research (CFAR) and the Medical Director of the HIV Clinic ("Ward 86") at San Francisco General Hospital. Her research focuses on HIV and women and adherence measurement in HIV treatment and prevention. She is now conducting research on mitigation strategies for COVID-19.