Immune Changes in Mothers, Infants Linked to COVID-19 Infection

P

regnant women may be hesitant to get the COVID-19 vaccine. As Infection Control Today® reported in October when the Centers for Disease Control and Prevention (CDC) issued an advisory to health care providers faced with vaccine hesitancy from pregnant women or women who’ve just given birth, misinformation may be fueling that hesitancy.1 Infection preventionists (IPs) have been urged to fight misinformation about COVID-19 among the public and even their fellow health care professionals. IPs know the reliable sources, are familiar with reading scientific studies, and are able to translate those findings to staff in an understandable way.2

One of those reliable sources is the Cleveland Clinic in Ohio. Investigators there sought to understand the clinical and immunological implications of COVID-19 on maternal-to-fetal health.

“We know that pregnancy increases maternal risk for COVID-19, but relatively little is known about the long-term consequences of in utero exposure for infants,” said Jae Jung, PhD, director of the Cleveland Clinic’s Global Center for Pathogen & Human Health Research.

The study included 93 mothers with COVID-19 and 45 of their infants who were exposed to the virus.3 Investigators compared maternal blood specimens collected close to the original date of COVID-19 infection and throughout pregnancy and delivery. They studied immune profiles for more than 1400 cytokines and other inflammatory proteins from the participants’ peripheral and cord blood samples.

At delivery, the women had dysregulated levels of many cytokines associated with pregnancy complications, such as MMP7, MDK, ESM1, BGN, and CD209. The infants expressed induction of T cell–associated cytokines IL33, NFATC3, and CCL21. Although most of the births were healthy, there was high incidence of certain complications such as fetal growth restriction and preeclampsia.

“Our findings show that COVID-19 infection during pregnancy leads to distinct immune alterations in mothers and babies, highlighting how important it will be for long-term follow-up after pregnancy to catch and hopefully prevent any unforeseen long-term health conditions related to prenatal infection,” Jung reported.

The investigators found different immune signatures between pregnant women with asymptomatic COVID-19 infection and those with severe COVID-19 infection. The mothers with severe disease had significantly more inflammation and elevated levels of the protein interferon lambda 1 (IFN-λ1) and its binding receptor, IFN-λR1.

“This increase in [IFN-λ] signaling may help explain why we see relatively little direct transmission of COVID-19 between mother and baby during the period right before or after birth—what we call vertical transmission,” said Suan-Sin Foo, PhD, one of the study’s authors.

There were no robust data suggesting vertical transmission, but the investigators found COVID-19 infection altered the mothers’ immunity at delivery, and gestational COVID-19 exposure altered the immunity of the newborns. “More research will be necessary to determine if increased expression of IFN-λ1 and I IFN-λR1 does in fact block vertical transmission,” Foo said.

The article originally appeared in Contagion®.

References:

1. Diamond F. Encourage pregnant women to get COVID-19 vaccine. Infection Control Today®. October 1, 2021. Accessed December 7, 2021. https://www.infectioncontroltoday.com/view/encourage-pregnant-women-to-get-covid-19-vaccine
2. Leach R. How infection preventionists can battle misinformation. Infection Control Today®. October 6, 2021. Accessed December 7, 2021. https://www.infectioncontroltoday.com/view/how-infection-preventionists-can-battle-misinformation
3. Foo SS, Cambou MC, Mok T, et al. The systemic inflammatory landscape of COVID-19 in pregnancy: extensive serum proteomic profiling of mother-infant dyads with in utero SARS-CoV-2. Cell Rep Med. 2021;2(11):100453. doi:10.1016/j.xcrm.2021.100453
4. Cosdon N. COVID-19 infection during pregnancy can cause immune changes in mothers and infants. Contagion®. November 24, 2021. Accessed December 7, 2021. https://www.contagionlive.com/view/covid-19-infection-during-pregnancy-can-cause-immune-changes-in-mothers-and-infants