An unvaccinated nurse lost her baby to Covid. Now she's urging new mothers to get the shot.

Vanessa Alfermann never got a chance to hold her son, Axel, before he died.

A nurse at Missouri Baptist Medical Center in St. Louis, Alfermann contracted coronavirus from her husband, Ryan, in November — mere weeks before the vaccine was available to health care workers. The virus led to a rushed trip to the hospital and an emergency birth at 20 weeks.

Axel did not survive.

Now Alfermann, 32, is sharing her story to encourage pregnant women to overcome their vaccine hesitancy and get the shot. She said she doesn't want them to go through the same hardship, shock and loss she suffered, especially if they have the opportunity to get the vaccination.

"They send you home and you have to start over," she said. "I was stuck in bed. I didn't talk to anyone — I just was in complete depression. It was devastating to lose Axel. It still is. I call him my missing piece."

Alfermann's decision to share her story coincides with the release of new research this month showing Covid-19 increases pregnancy risks, leading to pre-term births. A second study published earlier this week examined vaccine reactions among pregnant individuals and showed that vaccines were safe.

The Centers for Disease Control and Prevention and the American College of Obstetricians and Gynecologists also recently recommended that pregnant women receive the vaccine.

"These studies are huge and have substantial numbers," said Sabra Klein, co-director of the Center for Women’s Health, Sex and Gender Research at the Johns Hopkins Bloomberg School of Public Health. "This is data that you can believe in, and I think the message is very clear: If you are pregnant and not vaccinated, you should get vaccinated. You should be more afraid of this virus, especially these new variants, than you should be of the vaccine."

Despite being considered a high-risk population for Covid, less than a quarter of pregnant people have received at least one dose of a vaccine, according to the CDC.

That's a major issue, as the delta variant is much more infectious and has caused a huge number of unvaccinated people to be hospitalized.

A study from the University of California, San Francisco, released earlier this month found that the risk of pre-term births at less than 32 weeks was 60 percent higher among people infected by Covid during pregnancy, and the risk of giving birth at less than 37 weeks was 40 percent higher. The risk was also substantially higher among those who had hypertension, diabetes or obesity.

Deborah Karasek, an obstetrics and gynecology assistant professor and researcher with the California Preterm Birth Initiative at UCSF, led the study, which analyzed more than 240,000 births in California that occurred between July 2020 and January 2021, including nearly 9,000 cases in which the woman was diagnosed with Covid during pregnancy.

"Our study is representative of all the births in the state of California, so there's less potential for bias because it's a population-based study," Karasek said. "Our findings really build on a large body of evidence that we're seeing within the public health and medical community, and so I think taken together it really supports that we're seeing adverse effects of Covid infection in pregnancy."

A study from researchers at the University of Washington found that pregnant women did not have harmful or severe side effects from receiving the vaccination. More than 17,000 people participated in the study.

Experts agree these findings show a clear correlation, and some view them as a call for more pregnant people to get the vaccination to protect themselves and their children.

Doctors on the ground said the outcomes for pregnant Covid patients deteriorate.

Dr. Marta Perez, a Washington University in St. Louis laborist at Barnes-Jewish Hospital, said she has seen many pregnant women admitted to the intensive care unit with severe respiratory distress. They have been put on ventilators or machines that pump and oxygenate their blood outside the body to give their hearts and lungs a chance to rest.

Some Covid patients who gave birth in the hospital have died from complications caused by the virus and didn't get to meet their child. Others lost their baby or had to quarantine without meeting their newborn.

"We're seeing just all of these domino effects of really difficult situations with patients, many of them who may pass away without ever meeting their baby or may go weeks without meeting them," she said. "Other patients may unexpectedly be separated from their baby because, due to Covid, the child needs extra care we didn't anticipate."

Doctors and researchers said the biggest issue is misinformation, which has found a strong foothold among pregnant people and pregnancy groups online.

"Pregnant people are at greater risk of adverse pregnancy outcomes if they get infected, and there is no evidence that vaccination during pregnancy has adverse outcomes on either the pregnant person or the developing fetus," Klein said. "And that's it. Those are the facts."

Alfermann said there is a lot of misinformation among her patients and in conversations with friends and family. She said it is traumatizing to see those close to her spread bad information, and it has forced her to cut some people out of her life.

It's especially difficult to hear when she knows the effect Covid had on her pregnancy and the patients she and her colleagues are treating in the Covid ward every day.

"It's like we're drowning, and to be honest I'm pissed off," she said. "I'm mad we have to deal with this, and, to be a little selfish, I'm mad that I have to deal with this. But I love being a nurse, I love taking care of people, and I do it for Axel. No one else should have to lose their baby or their son or daughter or mother or father."

While Alfermann never had the opportunity to get the vaccination to protect her unborn son, she said pregnant individuals now have that chance. They should take advantage of it as soon as possible.

"I wish I could've gotten the shot six weeks earlier and my son would be here, but I couldn't," she said. "Others have that chance, though, and they can have their baby and be there for their baby. I just want Axel's legacy to be one that helps save someone, helps them get the vaccine, so that this never happens again."

CORRECTION (Aug. 21, 2021, 12:01 p.m. ET): A previous version of this article misstated Deborah Karasek’s title at the University of California, San Francisco. She is an assistant professor, not a professor.