Multigenerational Effects of Smallpox Vaccination

Can the effects of childhood vaccination extend across three generations? Using Swedish data spanning 250 years, we estimate the impact of smallpox vaccination on longevity, disability, and occupational achievements. Employing mother fixed-effects, difference-in-differences, and shift-share instrumental-variables designs, we find that vaccination improves health and economic outcomes for at least two subsequent generations. Causal mediation analysis reveals that these benefits arise from improved health behaviors and epigenetic factors. Even in milder disease environments as seen today, vaccination delivers lasting advantages, demonstrating its long-term benefits beyond epidemic contexts. These findings highlight the benefits of early-life health interventions lasting for subsequent generations.