Pfizer Versus Moderna COVID-19 Vaccine Effectiveness Against Mortality: Evidence from Linked Mortality and Vaccination Records in Indiana
Vaccines·
- DOI
- 10.3390/vaccines14080717
- PMID
- —
- PMCID
- —
- OpenAlex
- —
- Study type
- Journal article
- Publisher
- MDPI AG
- Article type
- journal-article
- Integrity
- current
Why this research matters now
The authors frame the findings as relevant to vaccination policy, arguing that controlling for healthy-vaccinee bias is important when comparing vaccine effectiveness and that, during a period of high vaccine availability and COVID-19 mortality, Moderna was associated with lower COVID-19 mortality than Pfizer. A higher Moderna dose is suggested as a possible explanation.
Structured evidence summary
Research question
Whether mRNA COVID-19 vaccines from Pfizer and Moderna differed in their effectiveness against COVID-19 mortality after accounting for healthy-vaccinee bias.
Study design
Retrospective observational study linking Indiana mortality records to vaccination records from January 2021 through December 2022, using a COVID-19 Excess Mortality Percentage (CEMP) metric that employs non-COVID natural mortality as a control for healthy-vaccinee bias. Remaining mortality risk (RMR) ratios compared Pfizer to Moderna recipients across age groups and time periods.
Population and setting
Persons aged 15 years and older who died in Indiana between January 2021 and December 2022, with linked vaccination records. Analyses were stratified by age (15–59 and 60+) and by time period, including a core period of 2Q 2021 through 1Q 2022 and a later period covering 2Q 2022 through 4Q 2022.
Main findings
Healthy-vaccinee bias was documented for both vaccines and was larger among Pfizer recipients. For ages 60+ during the core period (2Q 2021–1Q 2022), the Pfizer/Moderna remaining mortality risk ratio averaged approximately 1.49, indicating higher residual COVID-19 mortality among Pfizer recipients. For ages 15–59 the ratio was approximately 1.25 but was not statistically significant. Among ages 60+ booster recipients, the average Pfizer/Moderna RMR ratio was about 1.34. In the later 2Q 2022–4Q 2022 period, vaccine effectiveness was substantially lower and no significant Pfizer–Moderna difference was observed.
Public-health relevance
The authors frame the findings as relevant to vaccination policy, arguing that controlling for healthy-vaccinee bias is important when comparing vaccine effectiveness and that, during a period of high vaccine availability and COVID-19 mortality, Moderna was associated with lower COVID-19 mortality than Pfizer. A higher Moderna dose is suggested as a possible explanation.
Important limitations
The summary is limited to the supplied single-article abstract and metadata; the original paper would be needed for decision-grade interpretation. Explicit limitations are not detailed in the abstract, although the authors note that findings apply to the specific Indiana population studied and that earlier real-time comparisons of the two vaccines did not address healthy-vaccinee bias.
GIDS interpretation
This article is catalogued within GIDS-relevant topics of vaccination, vaccine effectiveness, and health policy, and relates to COVID-19 mortality outcomes. It may be discoverable as a methodological case study on healthy-vaccinee bias adjustment, but the abstract alone does not connect it to any live surveillance signal.
Related GIDS surveillance
Literature context does not validate, explain, or change a surveillance signal. Exact and contextual relationships are shown separately.
Evidence relationships
This article has 10 auditable classifier relationships to diseases, places, topics, and study design.