Interim estimates of 2018/19 vaccine effectiveness against influenza A(H1N1)pdm09, Canada, January 2019.
Using a test-negative design, the Canadian Sentinel Practitioner Surveillance Network assessed interim 2018/19 vaccine effectiveness (VE) against predominant influenza A(H1N1)pdm09 viruses. Adjusted VE was 72% (95% confidence interval: 60 to 81) against medically attended, laboratory-confirmed influenza A(H1N1)pdm09 illness. This substantial vaccine protection was observed in all age groups, notably young children who appeared to be disproportionately affected. Sequence analysis identified heterogeneity in emerging clade 6B.1 viruses but no dominant drift variant.
['Skowronski|Danuta M|DM|', 'Leir|Siobhan|S|', 'Sabaiduc|Suzana|S|', 'Murti|Michelle|M|', 'Dickinson|James A|JA|', 'Olsha|Romy|R|', 'Gubbay|Jonathan B|JB|', 'Croxen|Matthew A|MA|', 'Charest|Hugues|H|', 'Chan|Tracy|T|', 'Bastien|Nathalie|N|', 'Li|Yan|Y|', 'Krajden|Mel|M|', 'De Serres|Gaston|G|']
D000293:Adolescent D000328:Adult D000368:Aged D002170:Canada D016022:Case-Control Studies D002648:Child D002675:Child, Preschool D005260:Female D006385:Hemagglutination Inhibition Tests D006801:Humans D007223:Infant D053118:Influenza A Virus, H1N1 Subtype D007252:Influenza Vaccines D007251:Influenza, Human D008297:Male D008875:Middle Aged D009305:Nasopharynx D009666:Nose D017063:Outcome Assessment, Health Care D060888:Real-Time Polymerase Chain Reaction D012621:Seasons D012680:Sensitivity and Specificity D018571:Sentinel Surveillance D017422:Sequence Analysis, DNA D014611:Vaccination D064166:Vaccine Potency
vaccine effectiveness vaccines influenza Canada ILI epidemiology genomics immunisation influenza virus influenza-like illness laboratory vaccine-preventable diseases viral infections