Should you take COVID-19 vaccine during pregnancy? This is what the experts say.

For pregnant women, the deployment of COVID-19 vaccines is raising agonizing questions about whether it is safer to take the vaccine or risk of infection. Despite emerging evidence that vaccines are generally safe and effective, there is virtually no data on whether this is true for those waiting, although they have a higher risk of complications from the disease.

At times, global regulatory bodies have issued conflicting advice on pregnancy and COVID-19 vaccines. The Centers for Disease Control and Prevention (CDC) has said vaccines should be available for pregnant women, but ultimately leaves the decision in the hands of future parents and their doctors. The World Health Organization (WHO) recommends it, unless the pregnant person is at high risk.

So how can someone make a decision based on evidence about whether it is safe to take the vaccine if there is no safety data? “Everything revolves around the features of your life,” says Ruth Faden, founder of the Johns Hopkins Berman Institute of Bioethics in Maryland. Each person has to balance what is known about the vaccine with what is known about their own risk of becoming infected.

Although experts suggest talking these decisions with a medical provider, here you have a look at the facts available, what is still being resolved and why there are reasons to be optimistic.

Scientists generally know a lot about vaccines and pregnancy, although it has historically taken longer to obtain this evidence than general safety data. Due to the ethical complexity of pregnancy (in which parents and their fetuses face interconnected risks) and fears of legal liability, pregnant women are often excluded from the randomized clinical trials that are necessary to obtain the approval of a drug or vaccine.

In the past, it was 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 hesitate to get vaccinated and doctors may refrain from recommending them.

“What has resulted from this has been essentially unfair decades with pregnant women,” says Faden, who also leads the Pregnancy Research Ethics project for vaccines, epidemics, and new technologies (PREVENT). While it might sometimes make sense not to include prospective parents in early trials, she says, “we’ve been protecting pregnant women to death.”

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

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

On the other hand, vaccines that use a small amount of live viruses, such as measles, mumps, and rubella and chickenpox, can cause low-grade infections that some scientists worry could damage the fetus. But, Swamy says, “even this is based on theoretical risk problems,” not on tests that occur.

Modern and Pfizer-BioNTech vaccines for COVID-19 represent a new challenge. Until now, the RNA messenger platform they used was not licensed for human use. As such, the only available pregnancy-related data come from preclinical studies in laboratory animals and from a handful of participants in clinical trials who later discovered they were pregnant. (Here is the news about COVID-19 vaccines.)

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

Theoretically, all of this is promising because, like previous vaccines, it does not involve a live virus. “Everything that is understood to be biologically the case for mRNA vaccines is incredibly reassuring,” says Faden. “It should have no impact on pregnancy or pregnancy outcomes.”

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

However, scientists have raised questions about how mRNA vaccines will work in reality. The biggest concern is whether mRNA can cross the placenta and generate spike protein in the fetus. It wouldn’t necessarily be harmful if it did (and didn’t cause birth defects), but the concern is that the fetus may experience side effects, including pain, swelling, and fever. Swamy says animal studies showed no signs of physical side effects, but this has yet to be proven in humans.

Side effects on the mother can also be a problem. Christina Chambers, a perinatal epidemiologist at the University of California, San Diego, is conducting a study on pregnant women vaccinated against COVID-19. She points out that it can be harmful to the baby when a pregnant woman has a high fever. “If this is a side effect, you’d like to pay attention to it and talk to your provider about how to take something to reduce the fever,” he says.

There are ongoing clinical trials to investigate the effects of vaccines on pregnant women. Faden wants these trials to begin as soon as the vaccines received FDA approval, but notes that the process continues to move faster than in the past.

“We used to feel like one or two lone drums out there, beating our drums in that vast silence,” he says. “Now we have a whole percussion section that asks for more data and the inclusion of pregnant women in the launch of the vaccine. And that’s really good. “

On the other hand, we know a lot about the risks that COVID-19 presents for future parents. “There’s no doubt that pregnant women are worse than people who aren’t pregnant,” Swamy says.

Studies have shown that people pregnant with COVID-19 have a higher risk of hospitalization, ICU admissions, and mechanical ventilation. In January, a study was published in the journal JAMA Internal Medicine found that COVID-19 was associated with higher probabilities of blood pressure problems and premature birth, although there was no further chance of stillbirth. And a study in October found that one in four pregnant women may be COVID-19 “long-distance,” whose symptoms can persist for weeks or even months.

But the risk of serious illness is lower for people who expect it than for other high-risk groups, such as the elderly or those with heart disease. Therefore, it is critical to analyze the individual factors that increase a person’s individual risks, including the number of daily contacts, access to tests and high-quality PPE, and comorbidities such as asthma or obesity, and whether something can be done to reduce them.

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

For pregnant women who are at high risk of exposure and do not have the option to reduce this risk, it may make sense to consider the vaccine as soon as they are eligible. But to know for sure, Chambers says, “the urgency is to get the data on people getting vaccinated.”

There is reason to hope that scientists will soon better understand how COVID-19 vaccines work during pregnancy. In the short term, scientists look forward to data from pregnant health workers who began getting the vaccines in December. Faden says the data should be solid, as more than 15,000 pregnancies among vaccinated people were reported to the CDC on Jan. 20.

Beyond mRNA vaccines, there are some new options on the horizon. Johnson & Johnson filed its vaccine for FDA approval on Feb. 4, while AstraZeneca and Novavax have recently released data from three critical phase trials. All three vaccines are based on technologies studied in pregnant women in the past, which Swamy says could provide more peace of mind. (Should people get more than one type of vaccine against COVID-19?)

Recent studies have also suggested that there may be additional benefits to vaccination during pregnancy. A study published in the journal JAMA Pediatrics showed that women who have been infected with COVID-19 effectively transfer protective antibodies to their babies, especially if they are infected before pregnancy. The study does not suggest that this transfer will occur after vaccination, notes co-author Karen Puopolo, a neonatologist at Pennsylvania Hospital. But Swamy says it’s good news that antibodies regularly cross the placenta into a natural infection and he expects vaccination to have a similar response.

“It tells us that vaccinating women could have that kind of price for one,” she says, “that by vaccinating women we’re also providing some benefit during early childhood.”