Parental Bacillus Calmette-Guérin vaccine scars decrease infant mortality in the first six weeks of life: A...

Area of Science:

• Immunology
• Pediatrics
• Public Health

Background:

• Live attenuated vaccines, like BCG, show enhanced child survival benefits when infants have maternally transferred immunity (priming).
• The role of paternal priming in conjunction with maternal priming requires further investigation.

Purpose of the Study:

• To investigate the impact of parental Bacillus Calmette-Guérin (BCG) scars on infant mortality.
• To explore the potential of parental priming, including paternal influence, on early-life survival.

Main Methods:

• An exploratory, retrospective cohort study in 2017 assessed parental BCG scars in infants from a 2008-2013 neonatal BCG vaccination trial.
• Mortality from birth to 42 days was analyzed using Cox proportional hazard models with Inverse Probability of Treatment Weighting.

Main Results:

• Maternal BCG scars were associated with a 60% reduction in infant mortality, most pronounced when infants also received BCG at birth.
• Paternal scars showed a 49% reduction in mortality. Infants with both parents scarred had an 89% mortality reduction.
• BCG scar prevalence was 77% in mothers and 63% in fathers.

Conclusions:

• Parental BCG scars are associated with significantly improved early-life survival in infants.
• These findings highlight the importance of studying inherited non-specific immunity and parental priming for child health interventions.