Global Implications of Vaccination and Rising Infant Mortality in the Philippines

Abstract

Background and Objectives: Few metrics depict a nation's health more accurately than the infant mortality rate. Globally recognized as a barometer of population health, infant mortality reflects the effectiveness of health systems and policies. The infant mortality rate in the Philippines fell from 15.69 (2000) to 11.05 (2020) but then rose by 37% to 15.11 by 2024. Such a stark reversal in infant mortality patterns in just 5 years warrants an urgent investigation.
Methods: Primary data sources included Philippines Statistics Authority vital statistics (41.7M births/0.55M infant deaths 2000-2024) annual cause-of-death patterns (2015-2024), and annual infant cause-of-death across the first year of life (2020-2024). These were supplemented by the Philippines Department of Health Field Health Services Information System Annual Reports (2000-2024) which provide data on vaccination coverage, to support this detailed examination of Filipino infant mortality. Infant mortality trends were analyzed via linear/chi-square tests; correlations with vaccines; cause-of-death peaks were mapped to the National Immunization Program infant vaccination schedule; and confounders eliminated. Given the absence of pregnancy-specific COVID-19 vaccination records, population-level adult vaccination timelines and pregnancy-vaccination recommendations were temporally aligned with infant mortality, congenital abnormality trends, and monthly death patterns to assess possible associations.
Results: Infant mortality in the Philippines dropped steadily from 2000 (15.69) to 2005 (12.83), held steady up to 2019 (average 12.59, range 11.89 - 13.09), dropped to 11.05 (-14.9%) in 2020 but then rose to 15.11 (+37%) by 2024 (p < 0.0001). The rapid rise in infant mortality from 2020 to 2024 indicates serious declines in infant health. Births rose by 0.14% annual average growth from 2000 to 2012, peaking at 1.79 million in 2012, fell by annual averages of 1.0% to 1.67 million by 2019, and further by annual averages of 3.9% to 1.36 million in 2024, representing a highly significant 24% decline (p < 0.0001) in registered live births since 2012. Postnatal vaccines demonstrate mixed temporal associations with infant mortality trends: higher uptake of live vaccines correlated with declines in infant mortality, while inactivated vaccines correlated with rising infant mortality. The small sample size necessitates further analyses to further investigate and corroborate these findings. Between 2015 and 2024, excluding 2020 which had atypically low infant mortality, the correlation between Pneumococcal Conjugate Vaccine and the infant mortality rate was highly statistically significant (r=0.93, P=0.00074). While this correlation dropped with the addition of 2024 data, it was still significant (r=0.77, p=0.016), indicating a strong association between increasing Pneumococcal Conjugate Vaccine coverage and the observed infant mortality rise. Peaks in infant mortality across the first year of life match the timing of administration of the nation's standard vaccines. Further, the timing of the infant mortality rate inflection aligns with the national COVID-19 vaccination rollout. After two decades of declining infant mortality, the sharp post-2020 rise coincided with widespread maternal exposure beginning in 2021. Congenital abnormality deaths increased by 46% from 2020-2024. Several infant cause-of-death categories rose sharply including respiratory diseases (+124%), infectious and parasitic diseases (+125%), nervous system diseases (+11%), and unexplained sudden deaths (+106%). Synchronized increases across multiple cause-of-death categories and fetal-development linked outcomes are evident in the first birth cohorts gestated after large-scale population and maternal COVID-19 vaccination.
Conclusion: Our analysis of infant mortality trends in the Philippines identifies temporal associations between increased infant mortality and specific aspects of the national vaccination program. Notably, early neonatal deaths show a link with birth-dose administration of Hepatitis B and Bacillus Calmette-Guerin vaccines, warranting careful re-evaluation of this policy. Similarly, rises in infant mortality coincide with expanded uptake of the Pneumococcal Conjugate Vaccine (co-administered with pentavalent and polio vaccines), suggesting the need to reassess its role and the potential impacts of multiple concurrent vaccinations in the standard schedule. Further research is needed to investigate possible vaccine-related risks to fetuses and infants, including evidence of mRNA vaccine transfer to placental and reproductive tissues alongside infant mortality inflections temporally aligned with maternal COVID-19 vaccination rollout.