Seroconversion to Seasonal Influenza Viruses after A(H1N1)pdm09 Virus Infection, Quebec, Canada
Notice bibliographique
Résumé
We looked for cross-reactive antibodies in 122 persons with paired serum samples collected during the 2009 pandemic of infl uenza virus A(H1N1)pdm09.Eight (12%) of 67 persons with A(H1N1)pdm09 infection confi rmed by reverse transcription PCR and/or serology also seroconverted to the seasonal A/Brisbane/59/2007 (H1N1) virus, compared with 1 (2%) of 55 A(H1N1)pdm09-negative persons (p<0.05).T he role of seasonal 2008-09 trivalent inactivated infl uenza vaccines in protecting against infl uenza A(H1N1)pdm09 virus remains controversial (1).Recent reports indicated that prior infections with seasonal infl uenza A viruses protected against A(H1N1)pdm09 virus infection, suggesting the presence of cross-reactive antibodies (2).Several studies have proposed that humoral immunity and conserved B-and T-cell epitopes contribute to heterosubtypic protection (3,4).Our objective was to determine whether A(H1N1)pdm09 infection induced cross-reactive antibodies against seasonal infl uenza A (H1N1) and A (H3N2) viruses. The StudyThis investigation was part of a trial evaluating A(H1N1)pdm09 transmission among household contacts, conducted during the fi rst wave of the 2009 pandemic (May-July 2009) in Quebec City, Quebec, Canada (5).Clinical data and samples were serially obtained from index case-patients and their contacts in 42 households.Nasopharyngeal secretions were collected from all participants during the fi rst visit and tested by 2 different assays: a conventional reverse transcription PCR (RT-PCR) targeting the hemagglutinin gene of A(H1N1)pdm09 virus ( 6) and a universal RT-PCR targeting the matrix gene of all infl uenza A viruses (7).Blood was collected from persons >7 years of age at their initial visit (acute-phase sample) and 3-4 weeks later (convalescent-phase sample).Serum was tested by microneutralization assay according to World Health Organization standard protocols with minor modifi cations (8).This serologic study comprised 122 persons from the 42 households.Twenty-four persons were RT-PCRconfi rmed index case-patients (median age 15 years, range 7-56 years), and 98 were household contacts (median age 30.5 years, range 7-61 years), of whom 34 also were positive for A(H1N1)pdm09 virus by RT-PCR.For 67 patients (median age 20 years, range 7-61 years), A(H1N1)pdm09 was confi rmed by RT-PCR and/ or microneutralization assay: 10 (15%) by RT-PCR alone, 9 (13%) by microneutralization assay alone, and 48 (72%) by RT-PCR and microneutralization assay.Of the 67 A(H1N1)pdm09-infected persons, 8 (12%) seroconverted to A/Brisbane/59/2007 (A[H1N1] vaccine strain for 2008-09) (online Appendix Table, wwwnc.cdc.gov/EID/article/18/7/11-1680-TA1.htm).Seven A/ Brisbane/59/2007 seroconverters were RT-PCR positive and A(H1N1)pdm09 seroconverters, and 1 was RT-PCR positive and a A(H1N1)pdm09 nonseroconverter.In comparison, 1 (2%) of the 55 A(H1N1)pdm09-negative patients seroconverted to A/Brisbane/59/2007 (Fisher exact test, p<0.05).Seasonal infl uenza viruses were not circulating in the province of Quebec at the time of this study.Only 1 of 9 A/Brisbane/59/2007 seroconverters had previously received the inactivated 2008-09 seasonal infl uenza vaccines.No participants were vaccinated against A(H1N1)pdm09 virus, and none received antiviral therapy or prophylaxis.We then assessed whether this cross-reactivity was limited to the A/Brisbane/59/2007 strain, the most recent seasonal A (H1N1) virus to have circulated before A(H1N1)pdm09 virus, or whether it was broader.To this end, we tested all paired serum samples against an older seasonal A (H1N1) infl uenza virus, i.e., A/New Caledonia/20/1999 (H1N1 vaccine strain used during the 2000- 01 through 2006-07 seasons), and a past A(H3N2) virus, i.e., A/Panama/7/2004 (H3N2 vaccine component used during the 2000-01 through 2003-04 seasons).Seven (10%) A(H1N1)pdm09 virus-positive persons also seroconverted to A/New Caledonia/20/1999(H1N1), all of
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,001 |
| Études des sciences et des technologies | 0,002 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».