An international team led by researchers at the University of British Columbia says the immune system’s earliest steps are governed by a largely conserved programme across populations, but that measurable regional differences in gene activity during the first seven days of life could influence vulnerability to infection and responses to vaccines.
Common blueprint, local variation
Analysing blood samples taken during the first week after birth from two geographically distinct cohorts — newborns in The Gambia and Papua New Guinea — investigators found that a core sequence of immune development is shared across both groups. According to the study published in Nature Communications, between 88 and 96 per cent of the early immune "blueprint" was common to babies in the two settings.
But the team also identified a subset of roughly 600 genes whose expression differed between the cohorts. Those genes include ones involved in recognising and clearing foreign substances and other pro‑inflammatory responses, factors that play key roles in how a newborn reacts to pathogens.
“These differences are frequently involved in response to infections and could be used to predict susceptibility and response to infection throughout the first year of life,” said Dr. Bob Hancock, a professor in the Department of Microbiology and Immunology at UBC and senior author of the study.
Method and scale
Through the Expanded Program on Immunization Consortium, clinical researchers secured parental consent to collect serial blood samples from 90 newborns at multiple timepoints across their first week. Aliquots of those samples were shipped to UBC, where the research group profiled gene activity — measuring whether particular genes were turned up or down — to map immunological development.
Previous work by the team had shown that the earliest steps of immune maturation follow a robust and tightly regulated course. This follow-on analysis aimed to separate the invariant features of that course from population-specific strands that overlay it.
Implications for infant health and immunisation
Infancy is a period of heightened susceptibility to infectious disease, particularly in low- and middle-income countries where the burden of early-life infection remains high. The study’s authors note that understanding both the shared programme and the population-specific differences is essential for designing interventions to reduce infant morbidity and mortality.
Dr. Hancock and colleagues suggest the differing gene-expression patterns could help predict which infants are at greater risk of infection or might respond differently to vaccines during their first year.
- Shared trajectory: 88–96% of immune-development patterns common to both cohorts.
- Population-specific signals: ~600 genes showed differing expression between The Gambia and Papua New Guinea cohorts.
- Sample size: Serial blood samples from 90 newborns collected within the first seven days of life.
| Measure | Result |
|---|---|
| Shared immune programme | 88–96% |
| Genes with population-specific expression | ~600 |
| Newborns sampled | 90 |
The research underscores that while human immune development has a conserved core, local environmental, genetic or microbial exposures may leave distinct molecular signatures very early in life. Those signatures, the authors argue, could be harnessed to forecast infection risk trajectories and tailor public-health responses.
As the global public-health community continues to refine neonatal care and vaccination policies, the study provides evidence that a one-size-fits-all approach may overlook biologically meaningful differences that emerge in the first days after birth.
Further work will be needed to clarify the causes of the population-specific gene-expression patterns and how they relate to clinical outcomes across infancy. For now, the findings add a new layer of detail to how scientists think about immunity’s opening chapter in human life.
