Is the study showing increased infant deaths after 2 month vaccinations a good study?

1. What the study actually did and what its authors say

The investigators analyzed Louisiana Department of Health records that linked immunization and death registries and report working with 1,225 eligible children who later died before age three, comparing whether children vaccinated between 60–90 days died between 90–120 days of life versus those unvaccinated in the same window, and explicitly describe the work as a proof-of-concept that such datasets can show statistically significant harm which they urge be corroborated elsewhere ^{[1] [5]}.

2. Core methodological weaknesses that undermine causal claims

The analysis sampled only children who died (cases) rather than following a defined birth cohort with living controls, which introduces severe selection and survival biases because denominators and the population at risk are not represented; the authors themselves call for corroboration using linked registries across jurisdictions, implying their dataset alone cannot generalize ^[1]. Prior vaccine–SIDS research and official reviews emphasize that age distribution of SIDS peaks at 2–4 months and that temporal clustering after routine visits can reflect expected timing rather than causation unless carefully controlled for confounders such as underlying illness that delays or accelerates vaccination ^{[6] [7] [3]}.

3. How this sits against the broader evidence and expert assessments

Major reviews and surveillance systems have repeatedly concluded that vaccines are not linked causally to sudden infant death, and some large studies even show vaccination correlates with lower SIDS risk; CDC and American Academy of Pediatrics summaries state extensive research finds no evidence that vaccines cause SIDS and emphasize safe sleep practices as the primary prevention strategy ^{[2] [4] [8]}. At the same time, independent analyses (including VAERS-based work) have reported temporal clustering of some post-vaccination deaths, but those datasets are passive, prone to reporting biases, and cannot by themselves establish causality ^{[9] [10]}.

4. Signals, plausibility, and the scientific standard for action

A statistical signal in a restricted dataset is a legitimate reason for further study—but not for concluding harm; establishing causality would require population-based cohort or case-control designs with complete denominators, adjustment for confounders (birthweight, prematurity, recent illness, socioeconomics), blinded cause-of-death review or autopsy data, and replication across independent registries, all of which this preprint does not provide ^{[1] [7]}. The authors’ call for transparency and dataset availability is appropriate ^[5], but their published conclusions overreach what the presented methods can support.

5. Balanced verdict: useful signal, not a good causal study

The Louisiana analysis is useful insofar as it demonstrates the feasibility of linking immunization and mortality registries and may generate hypotheses about timing and subgroups to investigate further, but it is not a robust epidemiologic study that can overturn extensive prior evidence rejecting a causal vaccine–SIDS link; the preprint’s sample selection, lack of cohort denominators, potential confounding, and reliance on a single-state registry mean it should prompt careful, well-controlled replication rather than alarm-driven policy change ^{[1] [2] [3]}.

6. What would make the finding credible

Credible evidence would come from multi-state or national linked birth–vaccination–death cohorts with population denominators, pre-specified analytic plans, control for known SIDS risk factors, blinded review of cause-of-death data, and independent replication; until such work appears, the correct interpretation is that this preprint raises a question but does not provide proof of increased mortality caused by routine 2‑month immunizations ^{[1] [6] [11]}.