A large international study suggests that getting vaccinated against COVID-19 during pregnancy—especially with a booster shot—may help protect mothers from preeclampsia, a serious pregnancy complication that can threaten the lives of both mother and baby.
The research, led by the INTERCOVID Consortium and published in the journal eClinicalMedicine, analyzed health data from 6,527 pregnant women across 18 countries between 2020 and 2022.
Preeclampsia is a condition marked by high blood pressure and signs of organ damage, usually appearing after 20 weeks of pregnancy.
It affects about 3 to 8 percent of pregnancies worldwide and is a leading cause of maternal and newborn illness and death. Scientists still do not fully understand why it happens, but inflammation and problems with blood vessels are believed to play important roles.
The new study compared pregnant women who received COVID-19 vaccines with those who did not, including women who had and had not been infected with the virus.
Researchers found that COVID-19 infection during pregnancy was linked to a higher risk of preeclampsia, especially among women who were not vaccinated.
In contrast, women who received vaccination—particularly those who also got a booster dose—had significantly lower rates of the condition.
According to the researchers, vaccination with a booster reduced the overall risk of preeclampsia by about one-third.
The protective effect was even stronger in women who already had health conditions such as diabetes, high blood pressure, or thyroid disorders. In this group, vaccination plus a booster lowered the risk by more than 40 percent.
Importantly, the benefits appeared to extend beyond protection from COVID-19 infection itself, suggesting the vaccine may influence the biological pathways involved in preeclampsia.
The study also found that vaccinated women were less likely to experience other serious pregnancy problems, including premature birth and severe illness in mothers and babies. These findings suggest that vaccination during pregnancy could provide broader health benefits than previously recognized.
Researchers believe the vaccine may help regulate the immune system and protect blood vessels, which could reduce the inflammation and vascular damage associated with preeclampsia.
Some scientists also note that certain vaccines can have “non-specific” benefits, meaning they strengthen the body’s defenses in ways that go beyond the targeted disease.
Experts involved in the study say the results highlight the importance of making COVID-19 vaccines easily available to pregnant people worldwide. They emphasize that vaccination programs should include booster doses and ensure equal access across countries and communities.
While more research is needed to fully understand how vaccination reduces preeclampsia risk, this study provides encouraging evidence that a simple preventive measure could help protect mothers and babies from one of pregnancy’s most dangerous complications.
Copyright © 2026 Knowridge Science Report. All rights reserved.
