100-Year-Old BCG Vaccine Protects Newborns, Infants Beyond TB Shielding Them Against Other Viral Infections

The 100-year-old Bacille Calmette-Guerin or BCG vaccine, protection against tuberculosis is one of the oldest and most commonly used vaccines used to inoculate 100 million newborns each year.

A EurekAlert! report said that given in nations with endemic TB, the vaccine has surprisingly been found to shield newborns, as well as young infants from multiple bacterial and viral infections not related to TB. There are even some proofs that it can lessen COVID-19 severity.

To understand the vaccine's mechanism of action, scientists at the Precision Vaccines Program at Boston Children's Hospital collaborated with the Expanded Program on Immunization Consortium or EPIC, an international team examining early life immunization, to gather and comprehensively profile blood specimens from newborns and infants immunized with BCG, with the use of a powerful "big data" method.

Findings of the study showed that the BCG vaccine "induces specific changes in metabolites and lipids" correlating with natural immune system responses.

More so, the findings of the study offer hint toward making other vaccines more effective in susceptible populations with distinct immune systems like newborns.

Big Data for Small Babies

Joann Diray Arce, PhD, the first author of the study published in the journal, Cell Reports, together with her colleagues, started with blood specimens from low-birthweight newborns in Guinea Bissau who were signed up in a randomized clinical trial to be inoculated with BCG either at birth or after a delay of six weeks.

Both groups had small blood samples taken at four weeks, following BCG was given to the first group, and before it was provided to the second group.

Using lipidomics and metabolomics, the team thoroughly profiled the effect of BCG immunization of the blood plasma of the newborns.

The study investigators discovered that BCG vaccines given at birth changed metabolite and lipid profiles in the blood plasm of the newborns, in a pattern different from those in the delayed-vaccine group. The changes associated with changes in the production of cytokines, a key feature of innate immunity.

Metabolic and Lipid Biomarkers

The study investigators had parallel results when they tested BCG in cord blood specimens from a group of Boston newborns and specimens from a separate NIH/NIAID-funded Human Immunology Project Consortium research of newborns in The Gambia and Papua New Guinea.

Arce explained that they now have some metabolic and lipid biomarkers of vaccine protection that they can test and manipulate in mouse models.

The first author added, that they examined three different BCG formulations and demonstrated that they converge on similar paths of interest.

Essentially, reshaping of the metabolome by BCG may add to the molecular mechanisms of the immune response of a newborn.

BCG, an 'Old School Vaccine'

According to the director of the Precision Vaccines Program and senior investigator of the study, Ofer Levy, MD, PhD said that a growing number of research reveals that the BCG vaccine shields against unrelated infections,,

As indicated in a similar Medical Xpress report, it is crucial that "we learn from BCG to better understand" how to shield newborns. BCG is an "old school" vaccine, made from a "live, weakened germ."

However, live vaccines like BCG appear to activate the immune system in a very different manner way in early life, offering expansive protection against an array of viral and bacterial infections.

There's a lot of work ahead to understand that, as well as use that information to build better vaccines for newborns and infants.

Related information about how the BCG vaccine helps reduce newborn deaths is shown on Telethon Kids Institute's YouTube video below:

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