Maggie Anthony did not have much time to think before receiving the COVID-19 vaccine. A labor nurse at Cambridge Hospital in Massachusetts, she suddenly heard from her manager that the injections would be available the next day. But with an 8-month-old baby breastfeeding at home, she wasn’t sure whether to accept it. Pregnant and lactating women were not included in the clinical trials of COVID vaccines, so there is no data on vaccine safety for these groups.
At first, Anthony thought she would refuse. She knew that in the UK, the National Health Service had said that people who are pregnant and breastfeeding should not be vaccinated. The Food and Drug Administration simply advises: “If you are pregnant or breastfeeding, discuss your options with your doctor.” But Anthony had another factor to consider: she regularly looks after COVID-positive women. “During delivery, in the operating room, on their faces – there is no distance,” she said. “So I know that I am definitely exposed.”
When the day came, she had her chance. What helped her decide, said Anthony, was to consider pregnancy and breastfeeding separately. In his opinion, it was “a little impossible to imagine a way” in which the vaccine’s fragile mRNA could reach or affect your breastfeeding baby. If she were still pregnant, with a baby sharing her blood through the placenta, she would have been more nervous. “It is certainly a completely different scenario in my mind,” she said.
Government guidelines and news headlines grouped breastfeeding and pregnant women when talking about the safety of the COVID vaccine. But as people try to make their own decisions without safety data, it can be useful to recognize that vaccination during pregnancy and lactation carries several theoretical risks – and potential benefits.
Christina Chambers, a perinatal epidemiologist and professor of pediatrics at the University of California, San Diego, said it’s never a good idea to combine pregnancy and breastfeeding when asking if something is harmful. Some drugs that are risky during pregnancy are also avoided by breastfeeding people, even when they are perfectly safe for a breastfeeding baby.
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Chambers said that vaccines in general, especially those like COVID vaccines, which do not contain live viruses, are unlikely to harm an unborn baby or a breastfeeding baby. “But they raise a few different kinds of questions” for those who are pregnant or breastfeeding, she added.
Some of these questions concern the way vaccines work in general – causing an immune response. Can triggering an immune response during the first few weeks of pregnancy increase the risk of miscarriage? If they have an anaphylactic reaction or a high fever in response to the injection, could it affect the baby in any way? These are the types of questions that researchers will try to answer in future clinical trials.
However, with breastfeeding, these concerns do not apply. The main question is whether a dangerous amount of a substance is filtered into breast milk. For most drugs, Chambers said, “There is so little that strikes the baby that there is really very little theoretical risk.”
Even if a drug or vaccine ends up in breast milk, your journey to the baby does not end. “Everything that passes through breast milk also passes through the intestine,” said Helen Hare, a junior physician in acute medicine in Edinburgh, Scotland. Hare is co-author of a BMJ opinion article entitled “Breastfeeding healthcare professionals should receive the COVID-19 vaccine”. The delicate mRNA molecules in Pfizer or Moderna vaccines, if they entered milk, would then land in a baby’s stomach acid.
“If this vaccine worked orally, we wouldn’t be getting injections,” said Hare.
The Academy of Breastfeeding Medicine did the same in a December 14 statement. “During lactation, the vaccine’s lipid is unlikely to enter the bloodstream and reach the breast tissue,” wrote the authors. “If that happens, it is even less likely that the intact nanoparticle or mRNA will be transferred to milk. In the unlikely event that mRNA is present in milk, it is expected to be digested by the child and not have any biological effects ”.
Without clinical trial data on the subject, it is impossible for any organization or specialist to say with absolute certainty that there are no risks.
But even the World Health Organization suggests a less cautious approach to breastfeeding than pregnancy. For pregnant women, the WHO recommends not taking the Pfizer vaccine “unless the benefit of vaccination for a pregnant woman outweighs the potential risks of the vaccine”, as for health professionals at high risk of exposure. But, since the vaccine is “biologically and clinically unlikely to pose a risk to the breastfeeding child”, vaccines should be vaccinated just like anyone else.
Although the Academy of Breastfeeding Medicine says that vaccines pose an “unreasonable risk” for a breastfeeding child, it also says that there is a “biologically plausible benefit”.
After the vaccine activates the mother’s immune system to produce antibodies against SARS-CoV-2, the virus that causes COVID-19, these molecules can pass into breast milk. Babies usually get temporary protection from their mothers’ illnesses in this way. Researchers have already found COVID antibodies in the breast milk of previously infected women, although they do not yet know how much protection these antibodies offer babies.
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At UCSD, Chambers is working on studies of how COVID infection and vaccines affect mothers and babies during and after pregnancy. The women are also providing milk samples that the researchers will test for antibodies. (In a previous article, Chambers and the co-authors found no live viruses in the breast milk of infected women). The antibodies can also pass to the fetus of a person who was vaccinated during pregnancy, Chambers said.
During the first round of COVID vaccinations in the UK, women did not have a chance to weigh these factors on their own. If they were pregnant, breastfeeding or planning to become pregnant, they could not get the vaccine.
In their opinion article, Hare and co-author Kate Womersley, a junior academic physician in Edinburgh and an associate researcher at the George Institute for Global Health, wrote that “no plausible biological mechanism for explaining how an inactivated recombinant vaccine would harm a breastfed baby was proposed. ”Still, UK policy was forcing frontline healthcare professionals to make an impossible choice: they could forgo vaccination, wean their children before they were ready or lie.
Then, on December 30, government press releases about the authorization of a second vaccine in the UK mentioned – almost in passing – that the guidelines had changed. Those who are breastfeeding or pregnant were no longer eligible for the injection.
Womersley said it was “disappointing” that there was no clearer announcement about the new guidelines. She and Hare heard reports of women who had refused vaccines, even after the move. Unclear communication about vaccines harms women, said Womersley, by undermining public confidence.
Hare agreed that there should be better communication about vaccines, including the recognition that pregnancy and breastfeeding are two different things. “I think it helps to generate faith in the guidelines that the real situation is being considered,” she said.
Those who are pregnant and breastfeeding should also consider risk factors other than COVID itself, added Womersley – COVID is believed to be especially risky in pregnancy. “We must adapt the conversation differently for breastfeeding and pregnancy because the benefits and risks are different,” she said.
“I don’t think it helps any of the groups to group them together like that,” said Womersley. “The only thing that really unifies these two groups is that they are routinely discriminated against and excluded from the trials.”
This article was reproduced with permission from STAT. It was first published on January 19, 2021. Find the original story here.