ArticleProceedings of the National Academy of Sciences of the United States of America2014
Genesis and pathogenesis of the 1918 pandemic H1N1 influenza A virus.
Article in Proceedings of the National Academy of Sciences of the United States of America, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 153 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
153 citing papers in PubMed, 2 syntheses or guidelines pooled it, 284 citations in OpenAlex.
- Community Engagement Within the Evaluation of Public Policies for Zoonotic Spillover Prevention: A Secondary Matrix Analysis.International journal of environmental research and public health · 2025Pooled it
- Comparative Immunogenicity of Enhanced Seasonal Influenza Vaccines in Older Adults: A Systematic Review and Meta-analysis.The Journal of infectious diseases · 2019Pooled it
- Therapeutic potential of the sphingosine kinase 2 inhibitor opaganib.Pharmaceutical science advances · 2026Review
- Article
- Pre-existing and cross-reactive immunity to avian influenza H5N1 in humans: Implications for pandemic risk and vaccine strategies.The Journal of infection · 2026Review
- Immune imprinting in a changing world.Nature immunology · 2026Article
- Occupationally Exposed and General Population Antibody Profiles to Influenza A Viruses Circulating in Swine as Indication of Zoonotic Risk.Emerging infectious diseases · 2026Article
- Surveillance and cross-species transmission assessment of H3NX avian influenza viruses isolated in Guangdong province, China from 2023 to 2025.Poultry science · 2026Article
- Validation of a Qualitative Detection Method for Influenza A Virus RNA Based on the RT-RPA-CRISPR/Cas13a System.Current microbiology · 2026Article
- Multiplex serological profiling reveals diverse avian and mammalian influenza A virus exposure in swine.iScience · 2026Article
- Article
- The 'Spanish' influenza pandemic: new evidence for influenza outbreaks in England and France prior to 1918.Medical history · 2026Article
- Childhood immune imprinting shapes cohort and period influenza mortality.Science advances · 2026Article
- Mapping global avian influenza risk patterns through waterbird activity entropy.Nature communications · 2026Article
- PB1 mutations as key drivers of influenza A virus evolution.Frontiers in microbiology · 2026Review
- The potential of H5N1 viruses to adapt to bovine cells varies throughout evolution.Nature communications · 2025Article
- Eurasian 1C swine influenza A virus exhibits high pandemic risk traits.Emerging microbes & infections · 2025Article
- Avian-origin influenza A viruses tolerate elevated pyrexic temperatures in mammals.Science (New York, N.Y.) · 2025Article
- H1N1 challenge results in rapid recall of stem-specific immunity in HA stem nanoparticle-vaccinated newborn monkeys.JCI insight · 2025Article
- Antiviral Inactivated Vaccines: Looking to the Past to Face the Future-A Narrative Review.Vaccines · 2025Review
93 more citing papers are in PubMed but not listed here.
Corrections and comments
- Commented on by
Authors and funding
3 authors at 2 institutions in 3 countries.
Funding
Abstract
The source, timing, and geographical origin of the 1918-1920 pandemic influenza A virus have remained tenaciously obscure for nearly a century, as have the reasons for its unusual severity among young adults. Here, we reconstruct the origins of the pandemic virus and the classic swine influenza and (postpandemic) seasonal H1N1 lineages using a host-specific molecular clock approach that is demonstrably more accurate than previous methods. Our results suggest that the 1918 pandemic virus originated shortly before 1918 when a human H1 virus, which we infer emerged before ∼1907, acquired avian N1 neuraminidase and internal protein genes. We find that the resulting pandemic virus jumped directly to swine but was likely displaced in humans by ∼1922 by a reassortant with an antigenically distinct H1 HA. Hence, although the swine lineage was a direct descendent of the pandemic virus, the post-1918 seasonal H1N1 lineage evidently was not, at least for HA. These findings help resolve several seemingly disparate observations from 20th century influenza epidemiology, seroarcheology, and immunology. The phylogenetic results, combined with these other lines of evidence, suggest that the high mortality in 1918 among adults aged ∼20 to ∼40 y may have been due primarily to their childhood exposure to a doubly heterosubtypic putative H3N8 virus, which we estimate circulated from ∼1889-1900. All other age groups (except immunologically naive infants) were likely partially protected by childhood exposure to N1 and/or H1-related antigens. Similar processes may underlie age-specific mortality differences between seasonal H1N1 vs. H3N2 and human H5N1 vs. H7N9 infections.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.