Evidence map›Paper›PMID 41937191›Full record

ArticleVirology journal2026

Assessment of pre and postinfection immunity to the hemagglutinin proteins of Influenza A(H1N1)pdm09 and Influenza A(H3N2) in India: a retrospective longitudinal study.

Anup Jayaram, Desmond Cardoso, Arun M T, Prasad Varamballi, Kavitha Karunakaran, Prachi Malsane, Sudheesh N, Ujwal Shetty, Naren Babu N, Chiranjay Mukhopadhyay and 1 more

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Article in Virology journal, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

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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.

2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

11 authors.

Anup Jayaram *Manipal Institute of Virology, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India.
Desmond Cardoso *Manipal Institute of Virology, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India.
Arun M TManipal Institute of Virology, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India.
Prasad VaramballiManipal Institute of Virology, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India.
Kavitha KarunakaranManipal Institute of Virology, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India.
Prachi MalsaneManipal Institute of Virology, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India.
Sudheesh NManipal Institute of Virology, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India.
Ujwal ShettyManipal Institute of Virology, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India.
Naren Babu NManipal Institute of Virology, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India.
Chiranjay MukhopadhyayManipal Institute of Virology, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India.
Anitha JagadeshManipal Institute of Virology, Manipal Academy of Higher Education, Manipal, 576104, Karnataka, India. anitha.j@manipal.edu.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundHemagglutinin (HA), one of the main surface glycoproteins of the influenza virus, is essential for viral entry into host cells. Antibodies targeting HA can neutralize the virus, offering protection against infection. HA-specific antibody titers are therefore key markers of immune protection and vaccine efficacy. However, data on humoral immune responses to influenza A(H3N2) and influenza A(H1N1)pdm09 and viruses in India remain limited. METHODOLOGY: Laboratory-confirmed influenza specimens from 2016 to 2017 were analyzed in this retrospective longitudinal study. A systematic random sampling method was used to obtain 160 paired serum samples, distributed among four distinct age groups. Hemagglutination inhibition (HAI) assays were performed to assess the antibody responses against influenza A(H3N2) and influenza A(H1N1)pdm09 viruses following natural infection. Additionally, preexisting antibodies and antibodies to heterologous influenza strains were evaluated.

resultsFollowing natural infection, seroconversion rates were 77.1% for individuals infected with influenza A(H3N2) and 84.9% for those infected with influenza A(H1N1). Preexisting antibodies were detected in 40.8% of the acute-phase influenza A(H3N2) samples and 17% of the acute-phase influenza A(H1N1)pdm09 samples. Antibodies to heterologous strains were also detected in both groups, particularly between influenza A(H1N1)pdm09 and influenza A(H3N2), as well as with influenza B lineages.

conclusionThe results of this study show that most of the study population had evidence of immunity against both influenza A(H3N2) and influenza A(H1N1) virus strains. Evidence of antibodies to other influenza strains was also observed in a few samples, thus emphasizing the need for continuous monitoring and tailored vaccination strategies in India.

Indexed as

Antibodies, ViralHemagglutinin Glycoproteins, Influenza VirusInfluenza A Virus, H1N1 SubtypeInfluenza A Virus, H3N2 SubtypeInfluenza, HumanAdolescentAdultChildChild, PreschoolFemaleHemagglutination Inhibition TestsHumansIndiaInfantInfluenza VaccinesLongitudinal StudiesAntibodies, ViralHemagglutinin Glycoproteins, Influenza VirusInfluenza VaccinesCross-reactive antibodiesGood HealthHA-specific antibodiesHumoral immune responseInfluenza virusNatural infectionPreexisting antibodies

Identifiers

PMID41937191
PMCPMC13220398

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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.