ArticleBMC infectious diseases2017
Relative incidence and individual-level severity of seasonal influenza A H3N2 compared with 2009 pandemic H1N1.
Article in BMC infectious diseases, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 30 papers.
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Who cites it
30 citing papers in PubMed.
- Measuring population immunity against influenza using individual antibody titres: a multicountry, retrospective observational study.The Lancet. Infectious diseases · 2026Observational
- Severity of Clinical Presentation and Outcomes in Hospitalized Adult People With Influenza by Type and Subtype, United States-2017-2020.Clinical infectious diseases : an official publication of the Infectious Diseases Society of America · 2026Article
- The mediating role of acute respiratory infections in temperature-mortality associations in the Czech Republic, 1982-2019.International journal of biometeorology · 2026Article
- Reconstructed influenza A/H3N2 infection histories reveal variation in incidence and antibody dynamics over the life course.PLoS biology · 2024Article
- Evaluating Seasonal Variations in Human Contact Patterns and Their Impact on the Transmission of Respiratory Infectious Diseases.Influenza and other respiratory viruses · 2024Article
- Seasonality of influenza-like illness and short-term forecasting model in Chongqing from 2010 to 2022.BMC infectious diseases · 2024Article
- Reconstructed influenza A/H3N2 infection histories reveal variation in incidence and antibody dynamics over the life course.medRxiv : the preprint server for health sciences · 2024Article
- Symptomatic Differences between Influenza A/H3N2 and A/H1N1 in Korea.Journal of clinical medicine · 2023Article
- Article
- Reconstructing antibody dynamics to estimate the risk of influenza virus infection.Nature communications · 2022Article
- Review
- Characterizing the transmission patterns of seasonal influenza in Italy: lessons from the last decade.BMC public health · 2022Article
- Infection with different human influenza A subtypes affects the period of susceptibility to secondary bacterial infections in ferrets.FEMS microbes · 2022Article
- A human-airway-on-a-chip for the rapid identification of candidate antiviral therapeutics and prophylactics.Nature biomedical engineering · 2021Article
- Characterising the epidemic spread of influenza A/H3N2 within a city through phylogenetics.PLoS pathogens · 2020Article
- Estimates of the severity of coronavirus disease 2019: a model-based analysis.The Lancet. Infectious diseases · 2020Article
- Estimating the Risk of COVID-19 Death During the Course of the Outbreak in Korea, February-May 2020.Journal of clinical medicine · 2020Article
- An open source tool to infer epidemiological and immunological dynamics from serological data: serosolver.PLoS computational biology · 2020Article
- Illness Severity in Hospitalized Influenza Patients by Virus Type and Subtype, Spain, 2010-2017.Emerging infectious diseases · 2020Article
- Comparison of the Pathogenicity in Mice of A(H1N1)pdm09 Viruses Isolated between 2009 and 2015 in Japan.Viruses · 2020Article
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10 authors.
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Abstract
backgroundTwo subtypes of influenza A currently circulate in humans: seasonal H3N2 (sH3N2, emerged in 1968) and pandemic H1N1 (pH1N1, emerged in 2009). While the epidemiological characteristics of the initial wave of pH1N1 have been studied in detail, less is known about its infection dynamics during subsequent waves or its severity relative to sH3N2. Even prior to 2009, few data was available to estimate the risk of severe outcomes following infection with one circulating influenza strain relative to another.
methodsWe analyzed antibodies in quadruples of sera from individuals in Hong Kong collected between July 2009 and December 2011, a period that included three distinct influenza virus epidemics. We estimated infection incidence using these assay data and then estimated rates of severe outcomes per infection using population-wide clinical data.
resultsCumulative incidence of infection was high among children in the first epidemic of pH1N1. There was a change towards the older age group in the age distribution of infections for pH1N1 from the first to the second epidemic, with the age distribution of the second epidemic of pH1N1 more similar to that of sH3N2. We found no serological evidence that individuals were infected in both waves of pH1N1. The risks of excess mortality conditional on infection were higher for sH3N2 than for pH1N1, with age-standardized risk ratios of 2.6 [95% CI: 1.8, 3.7] for all causes and 1.5 [95% CI: 1.0, 2.1] for respiratory causes throughout the study period.
conclusionsOverall increase in clinical incidence of pH1N1 and higher rates of severity in older adults in post pandemic waves were in line with an age-shift in infection towards the older age groups. The absence of repeated infection is good evidence that waning immunity did not cause the second wave. Despite circulating in humans since 1968, sH3N2 is substantially more severe per infection than the pH1N1 strain. Infection-based estimates of individual-level severity have a role in assessing emerging strains; updating seasonal vaccine components; and optimizing of vaccination programs.
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