Neonatology

Preterm, full-term infants have similar immunity to viruses

Preterm infants exhibited similar repertoires of maternal immunoglobulin G as full-term infants, which can protect against viruses such as respiratory syncytial virus, according to a study published in Nature Medicine.

“We need to reconsider our ideas that preterm children are more susceptible to infectious diseases due to a lack of maternal antibodies,” Petter Brodin, MD, PhD, associate professor in the Science for Life Laboratory and the department of women’s and children’s health at the Karolinska Institutet, told Infectious Diseases in Children.

Brodin and colleagues wrote that newborn infants cannot produce immunoglobulin G (IgG) antibodies until 15 weeks after birth, and during that time, the infants rely on passive immunity from maternal IgG.

“The concentration of IgG increases during the third trimester of gestation, and children delivered extremely preterm are believed to lack this passive immunity,” the researchers wrote.

They studied 78 mother and child pairs, which included 32 babies who were very premature (born before week 30) and 46 full-term babies. They measured antibodies against 93,904 epitopes from 206 viruses in the mother-child dyads.

They wrote that the extremely preterm children received “comparable repertoires of IgG” as term children, but the absolute concentrations were lower, which related to a shorter half-life. Neutralization of RSV also was comparable until 3 months of age.

“I hope this makes us question some preconceived ideas about the neonate immune system and infection sensitivity, so that we can take even better care of newborns,” Brodin said in a press release. “Premature babies can be especially sensitive to infection, but that is not because they lack maternal antibodies. We should concentrate more on other possible causes, maybe like their having underdeveloped lung function or weaker skin barriers.”

Brodin told Infectious Diseases in Children that the findings show what epitopes are targeted by maternal antibodies, “which will have important implications for vaccine development.” – by Bruce Thiel  (Pou C, et al. Nat Med. 2019;doi:10.1038/s41591-019-0392-8.)