Babies under six months are protected against COVID-19 hospitalization if their parent got vaccinated during pregnancy, a new study from the US Centers for Disease Control and Prevention suggests.
Two doses of Pfizer or Moderna mRNA vaccines during pregnancy were 61% effective at protecting against COVID-19 hospitalization in infants under six months, according to research published last month in the CDC's Morbidity and Mortality Weekly Report. The study, which didn't include information on those who were vaccinated before pregnancy or people who received Johnson & Johnson's vaccine, compared information from 20 pediatric hospitals in 17 states from July 2021 to January 2022.
"When people receive an mRNA COVID-19 vaccine during pregnancy, their bodies build antibodies to protect against COVID-19 and these antibodies have been found in umbilical cord blood," Dr. Meaney-Delman, chief of the CDC's Infant Outcomes Monitoring Research and Prevention Branch, said at a media briefing.
"And while we know that these antibodies cross the placenta, until this study, we have not yet had data to demonstrate whether these antibodies might provide protection for the baby against COVID-19," she said.
Completing the vaccine series later in pregnancy was more effective at preventing hospitalization of the infant (80%) compared to earlier in pregnancy (32% effective at up to 20 weeks), but the CDC notes this timeline comparison should be interpreted with caution.
The findings of the new study are important because COVID-19 vaccines for babies under six months aren't currently being developed. Pfizer and BioNTech's COVID-19 vaccine for children age 6 months through 4 years is currently being tested, after the companies and the US Food and Drug Administration decided to postpone authorization until more data on all three likely-needed doses are available.
While the newer study focused on protecting infants against COVID-19, earlier research has demonstrated the importance of pregnant people getting vaccinated for the sake of their own health and that of their developing fetus.
A large study from Scotland published in the journal Nature in January found that unvaccinated pregnant women were more likely to be sick with COVID-19, more likely to be hospitalized with the disease and that their babies and fetuses were more likely to die, compared with vaccinated people who got sick while pregnant.
Here's what the experts say about getting vaccinated during pregnancy.
The CDC made its official recommendation in August that, yes, pregnant people, breastfeeding people and those who want to be pregnant in the future should get vaccinated against COVID-19. The ACOG and SMFM also recommend COVID-19 vaccines for pregnant people.
Other vaccines are recommended or offered during pregnancy. Some vaccines, for other diseases, aren't recommended for pregnant people because they contain (very small amounts) of a live virus. None of the coronavirus vaccines available in the US uses a live virus, making them safe during pregnancy.
Do I need a booster if I'm pregnant? Which shot should I get?
You should get a booster of Pfizer's or Moderna's vaccine at least five months after your second Pfizer or Moderna, or at least two months after your Johnson & Johnson shot, according to guidance from the FDA and CDC. Everyone should choose a booster of Moderna or Pfizer, the CDC now says, because of the rare but serious risk of blood clots associated with J&J's vaccine. While rare overall, women ages 30 to 49 are at higher risk following the one-dose vaccine.
What are the side effects of the vaccine for pregnant people?
Preliminary data on about 35,000 pregnant people who were vaccinated and volunteered information through the V-safe program shows that pregnant people experience the same vaccine side effects that others have reported: temporary injection pain in the arm, fatigue, headache, muscle aches and fever.
However, it's important to note that fever from any cause has been associated with adverse pregnancy outcomes, and the CDC recommends pregnant people who experience fever after vaccination take acetaminophen to lower their body temperature. (Fever can also be a symptom of COVID-19.)
If you have specific questions about the vaccine or you have concerns in general, you can talk to an expert by emailing Mother to Baby or calling 1-866-626-6847.
Why are pregnant people at a high risk of COVID-19?
In May, CNET talked to Dr. Ella Speichinger, an OB-GYN at University of Missouri Health Care. She said it isn't exactly known why pregnant people are at a higher risk, but that it may be because pregnant people's immune systems are naturally depressed so that their bodies won't reject the growing fetus, or because pregnancy could alter the body's way of mounting an immune response to COVID-19.
"I've had many patients who have had COVID while they were pregnant, and they've been just fine," she said. "But there have definitely been severe cases where patients had to get delivered early because they could no longer oxygenate their fetus."
In the Nature study, the authors noted that while pregnant people aren't at an increased risk of catching COVID-19, they are more likely than people of the same age who aren't pregnant to be admitted to critical care and die from the disease if they do get sick.
During what trimester should I get the vaccine?
Scientists who looked at people who got vaccinated earlier than 20 weeks pregnant didn't find an increased risk of miscarriage compared with those who didn't, according to a report from the V-safe pregnancy registry. Earlier data that was available reflected vaccination during the later stages of pregnancy.
It may be that some people hold out on getting vaccinated during the first trimester due to the naturally high rate of miscarriage in the first three months, and patients being more cautious because of that. About 10% of known pregnancies end in miscarriage, according to the ACOG, but the risk also increases with age. About 80% of miscarriages happen in the first trimester.
"Most people feel concerned in the first trimester because there's such a high risk of miscarriage in general," Speichinger said. "Conflating the miscarriage with vaccine administration is what leads to vaccine hesitancy in the first trimester."
I'm skeptical of the vaccine. What are the risks of getting COVID-19 while pregnant?
Pregnant and recently pregnant people are at higher risk of severe illness from COVID-19, including death, according to the CDC, and they're also at increased risk for preterm delivery (birth before 37 weeks) and other adverse pregnancy outcomes including stillbirth. Other health factors of the pregnant person, including a high BMI, diabetes or heart conditions, may elevate this risk, according to the SMFM.
Unvaccinated people who give birth are also much more likely to have a perinatal death (death of a fetus or newborn within weeks of their birth), the large study from Scotland found.
In its latest report, the CDC made a strong recommendation that breastfeeding people and those who were recently pregnant get a COVID-19 vaccine.
Do the COVID-19 vaccines cause infertility?
All available research says the same thing: no. But a COVID-19 infection may make the male partner (temporarily) less fertile, one study suggests. The same study found no fertility differences in male partners who tested positive after about two months, however. Possible reasons for this include inflammation of the testes or erectile dysfunction.
The fear about infertility and COVID-19 vaccines stems from a now-debunked blog post that claimed the vaccine would make pregnant people's bodies attack a protein needed for placenta formation in early pregnancy because, it asserted, the spike protein in the COVID-19 vaccine is "similar." Experts have disproved this, saying that not only do the two proteins have "almost nothing in common," but even if they did, infection with COVID-19 would have the same outcome. And a past illness with COVID-19 has not been associated with a decrease in female fertility, either.
If you'd like information in the video form about COVID-19 vaccines and pregnancy, Dr. Danielle Jones, an OB-GYN who is also known as "Mama Doctor Jones" on TikTok, shared this video on YouTube debunking myths about COVID-19 vaccines and infertility, miscarriage and pregnancy.
The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.