Even premature babies carry anti-viral antibodies transferred from the mother, researchers at Karolinska Institutet in Sweden report in a paper on maternal antibodies in newborns, published in the journal Nature Medicine. The results should change our approach to infection sensitivity in newborns.
Antibodies are transferring from the mother’s blood to the fetus that gives the newborn passive defense against infection. Since most of this process takes place during the third trimester of the pregnancy; doctors have regarded very premature babies as unprotected by such maternal antibodies. However, now that the total repertoire of maternal anti-viral antibodies emerging.

Immune system and infection

“I hope that 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. “Premature babies can especially sensitive to infection, but that is not because they lack maternal antibodies. They should concentrate more on other possible causes may like their having underdeveloped lung function or weaker skin barriers.”
The study was using a newly developing method for simultaneously analyzing the presence of antibodies against all the viruses that can infect humans (with the exception of the Zika virus, which was identified later). The method is by US researchers and is based on a so-called bacteriophage display; a technique awarded with the 2018 Nobel Prize in Chemistry.

The specific surface protein

Briefly, it is based on the ability to make viral particles called bacteriophages display a specific surface protein. In this case, all in all, the bacteriophage library displayed over 93,000 different peptides; short-chain proteins, from over 206 species of virus and over 1 000 different strains. The library is with the blood plasma. Any antibodies in the plasma sample bind with the bacteriophages and can then detected by the researchers.

The analysis was on samples taken at birth and during the newborns’ first; fourth and twelfth week. The researchers found that the protection offered by the antibodies lasted different durations depending on the virus. This can suggest that their transfer during the fetal stage is regulating rather than random; a possibility the group is now examining further.

“If all maternal antibodies target a specific part of a virus protein; that is important to know because then it is that part a vaccine should be based on. “I hope that our results can used by others to develop better vaccines, such as against the RS virus that causes so much distress for babies every winter.”