Should you get the COVID-19 vaccine while you are pregnant? Here’s what experts say.

For people who are pregnant, COVID-19 vaccines raise troubling questions about whether it is safer to get the vaccine or to risk infection. Despite the emerging evidence that the vaccines are generally safe and effective, there is virtually no data on whether they are true for those who expect them, although they are at greater risk for complications of the disease.

The world’s regulatory bodies have sometimes given conflicting advice on pregnancy and COVID-19 vaccines. The Center for Disease Control and Prevention (CDC) said the vaccines should be available to pregnant people, but ultimately left the decision to the expectant parents and their doctors. The World Health Organization (WHO) recommends against it, unless the pregnant person is at high risk.

So, how does one make an evidence-based decision as to whether it is safe to get the vaccine if there are no safety data? “It all revolves around the characteristics of your life,” says Ruth Faden, founder of the Johns Hopkins Berman Institute of Bioethics in Maryland. Every person needs to balance what is known about the vaccine with what is known about their own risk of becoming infected.

Although experts suggest talking through these decisions with a medical provider, look at the available facts, which are still being sorted out and why there is reason to be optimistic.

Scientists generally know a lot about vaccines and pregnancy, although it has historically taken longer to obtain evidence than general safety data. Because of the ethical complexity of pregnancy – in which parents and their fetuses face interrelated risks – and the fear of legal liability, pregnant women are usually excluded from the random clinical trials required to obtain approval for a drug or vaccine. .

In the past, it took years after vaccines were approved for general use to collect enough data to show how they work during pregnancy. Many of these follow-up studies are observational and involve fewer participants. As a result, pregnant women may be reluctant to get a vaccine, and doctors may not recommend it.

“What resulted from this was essentially injustice to pregnant women,” says Faden, who also leads the project for pregnancy research ethics for vaccines, epidemics and new technologies (PREVENT). While it can sometimes make sense not to include expectant parents in early trials, she says, “We protected pregnant women to death.”

But scientists have gathered incontrovertible evidence that certain vaccines are safe, effective and in some cases urgently needed. Today, the CDC strongly encourages pregnant people to get vaccinated against the flu, which is known to cause serious complications in pregnant women. Medical experts also recommend taking the vaccine for whooping cough (or whooping cough), which can be fatal to newborns. Expectant people can also receive vaccinations for a handful of other diseases, including hepatitis and meningitis.

Lessons from the vaccines have shown that there is no reason to worry about the types of shots that an inactivated virus uses to elicit an immune response, as they cannot infect the parent or the baby, says Geeta Swamy, associate professor. in obstetrics and gynecology from Duke University School of Medicine in North Carolina and a leading researcher in maternal vaccination.

On the other hand, vaccines that use a small amount of live viruses – such as those for measles, mumps and rubella and chickenpox – can cause low-grade infections that some scientists worry could harm a fetus. But, says Swamy, “even if it is based on theoretical risks,” not on evidence that it occurs.

The Moderna and Pfizer BioNTech vaccines for COVID-19 are a new challenge. So far, the messenger RNA platform they use has not been licensed for human use. As such, the only pregnancy-related data are available from preclinical studies in laboratory animals and a handful of clinical trial participants who later discovered they were pregnant. (Here is the latest vaccine on COVID-19.)

But we do know a lot about how mRNA technology works. Instead of using inactivated or live viruses, these vaccines contain fragments of genetic code encased in lipids or fat globules, which protect the code against degradation. Once injected, the mRNA instructs cells to produce the SARS-CoV-2 ear protein, which triggers the body’s immune response.

Theoretically, this is all promising because, like vaccinations in the past, it does not involve a live virus. “Anything that is understood to be biologically the case with mRNA vaccines is incredibly reassuring,” says Faden. “It may not affect pregnancy or pregnancy.”

White House medical adviser Anthony Fauci also said the data “so far has no red flags” for pregnant people.

Yet scientists have asked questions about how the mRNA vaccines will actually work. The biggest concern is whether mRNA can cross the placenta and generate the protein from the vein in the fetus. It would not necessarily be harmful if it did happen – and would not cause birth defects – but the concern is that the fetus may experience side effects, including pain, swelling and fever. Swamy says the animal studies showed no signs of physical side effects, but it has yet to be tested in humans.

Side effects in the mother can also be a problem. Christina Chambers, a perinatal epidemiologist at the University of California, San Diego, is conducting a study of COVID-19 vaccinated pregnant women. She notes that it can be harmful to the baby if a pregnant woman has a high fever. “If it’s a side effect, you want to address it and talk to your provider about taking something to reduce fever, ‘she says.

Clinical trials are underway to investigate the effects of the vaccines in pregnant women. Faden wishes that these trials started once the vaccines were approved by the FDA, but she points out that the process is still moving faster than in the past.

“We used to feel like one or two lonely drums out there beating our drums in this awful silence,” she says. ‘Now we have a whole slaughter department asking for more information and the inclusion of pregnant women in the introduction of the vaccine. And that’s a really good thing. ‘

On the other hand, we know a lot about the risks that COVID-19 poses to expectant parents. “There is no doubt that pregnant women perform worse than non-pregnant people,” says Swamy.

Studies have shown that pregnant people with COVID-19 are at increased risk for hospitalization, ICU uptake, and mechanical ventilation. In January, a study appeared in the journal JAMA Internal Medicine found that COVID-19 was associated with a higher chance of blood pressure problems and premature birth, although the chance of stillbirth was not greater. And a study in October found that one in four pregnant people is COVID-19 ‘long-term sufferers’, whose symptoms can linger for weeks or even months.

But the risk of serious illness is less for the expectant people than for other high-risk groups, such as the elderly or people with heart disease. It is therefore critical to look at individual factors that increase a person’s individual risks, including the number of daily contacts, access to high-quality testing and PPE, and associated diseases such as asthma or obesity – and whether anything has been done. can be to reduce it.

Timing must also be considered. Swamy says there is no evidence that a vaccine can cause developmental problems or miscarriage in the first trimester. However, women at lower risk for infection may choose not to be vaccinated during the period, which is essential for the development of the fetal organ, and this is usually when miscarriages occur. (The flu vaccine is safe at any time during pregnancy.)

For pregnant women with a high risk of exposure and who do not have the option to reduce the risk, it may make sense to consider the vaccine once they are eligible. But to make sure, Chambers says, “the urgency is to get the information about people being vaccinated.”

There is reason to hope that scientists will soon have a better understanding of how COVID-19 vaccines work during pregnancy. In the short term, scientists are looking forward to the data of pregnant health workers who started taking the vaccines in December. Faden says the data should be robust, as more than 15,000 pregnancies were reported to the CDC on January 20.

In addition to the mRNA vaccines, there are some new options on hand. Johnson & Johnson submitted its FDA approval vaccine on February 4, while AstraZeneca and Novavax recently released critical phase three trial data. All three vaccines depend on technologies studied in the past in pregnant women, which, according to Swamy, could provide further reassurance. (Should people take more than one type of COVID-19 vaccine?)

Recent studies have also suggested that vaccination during pregnancy may have additional benefits. One study published in the journal JAMA Pediatrics showed that women infected with COVID-19 transmit effective protective antibodies to their babies – especially if they were infected earlier in pregnancy. The study does not suggest that this transmission will occur after vaccination, says co-author Karen Puopolo, who attends neonatology at Pennsylvania Hospital. But Swamy says it’s good news that antibodies regularly cross the placenta in natural infestation, and that she expects vaccination to have a similar response.

“It tells us that vaccinating women can have such benefits for one,” she says, “that through early childhood we also offer benefits by vaccinating women.”