tetano
Editor, Senior Moderator
Vaccine. 2019 Apr 2. pii: S0264-410X(19)30222-1. doi: 10.1016/j.vaccine.2019.02.027. [Epub ahead of print]
[h=1]Intraseason decline in influenza vaccine effectiveness during the 2016 southern hemisphere influenza season: A test-negative design study and phylogenetic assessment.[/h] Regan AK[SUP]1[/SUP], Fielding JE[SUP]2[/SUP], Chilver MB[SUP]3[/SUP], Carville KS[SUP]4[/SUP], Minney-Smith CA[SUP]5[/SUP], Grant KA[SUP]4[/SUP], Thomson C[SUP]6[/SUP], Hahesy T[SUP]7[/SUP], Deng YM[SUP]8[/SUP], Stocks N[SUP]3[/SUP], Sullivan SG[SUP]9[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] We estimated the effectiveness of seasonal inactivated influenza vaccine and the potential influence of timing of immunization on vaccine effectiveness (VE) using data from the 2016 southern hemisphere influenza season.
[h=4]METHODS:[/h] Data were pooled from three routine syndromic sentinel surveillance systems in general practices in Australia. Each system routinely collected specimens for influenza testing from patients presenting with influenza-like illness. Next generation sequencing was used to characterize viruses. Using a test-negative design, VE was estimated based on the odds of vaccination among influenza-positive cases as compared to influenza-negative controls. Subgroup analyses were used to estimate VE by type, subtype and lineage, as well as age group and time between vaccination and symptom onset.
[h=4]RESULTS:[/h] A total of 1085 patients tested for influenza in 2016 were included in the analysis, of whom 447 (41%) tested positive for influenza. The majority of detections were influenza A/H3N2 (74%). One-third (31%) of patients received the 2016 southern hemisphere formulation influenza vaccine. Overall, VE was estimated at 40% (95% CI: 18-56%). VE estimates were highest for patients immunized within two months prior to symptom onset (VE: 60%; 95% CI: 26-78%) and lowest for patients immunized >4 months prior to symptom onset (VE: 19%; 95% CI: -73-62%).
[h=4]DISCUSSION:[/h] Overall, the 2016 influenza vaccine showed good protection against laboratory-confirmed infection among general practice patients. Results by duration of vaccination suggest a significant decline in effectiveness during the 2016 influenza season, indicating immunization close to influenza season offered optimal protection.
Crown Copyright ? 2019. Published by Elsevier Ltd. All rights reserved.
[h=4]KEYWORDS:[/h] Case-control study; Influenza; Influenza vaccines; Test-negative design; Vaccine effectiveness
PMID: 30952499 DOI: 10.1016/j.vaccine.2019.02.027
[h=1]Intraseason decline in influenza vaccine effectiveness during the 2016 southern hemisphere influenza season: A test-negative design study and phylogenetic assessment.[/h] Regan AK[SUP]1[/SUP], Fielding JE[SUP]2[/SUP], Chilver MB[SUP]3[/SUP], Carville KS[SUP]4[/SUP], Minney-Smith CA[SUP]5[/SUP], Grant KA[SUP]4[/SUP], Thomson C[SUP]6[/SUP], Hahesy T[SUP]7[/SUP], Deng YM[SUP]8[/SUP], Stocks N[SUP]3[/SUP], Sullivan SG[SUP]9[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] We estimated the effectiveness of seasonal inactivated influenza vaccine and the potential influence of timing of immunization on vaccine effectiveness (VE) using data from the 2016 southern hemisphere influenza season.
[h=4]METHODS:[/h] Data were pooled from three routine syndromic sentinel surveillance systems in general practices in Australia. Each system routinely collected specimens for influenza testing from patients presenting with influenza-like illness. Next generation sequencing was used to characterize viruses. Using a test-negative design, VE was estimated based on the odds of vaccination among influenza-positive cases as compared to influenza-negative controls. Subgroup analyses were used to estimate VE by type, subtype and lineage, as well as age group and time between vaccination and symptom onset.
[h=4]RESULTS:[/h] A total of 1085 patients tested for influenza in 2016 were included in the analysis, of whom 447 (41%) tested positive for influenza. The majority of detections were influenza A/H3N2 (74%). One-third (31%) of patients received the 2016 southern hemisphere formulation influenza vaccine. Overall, VE was estimated at 40% (95% CI: 18-56%). VE estimates were highest for patients immunized within two months prior to symptom onset (VE: 60%; 95% CI: 26-78%) and lowest for patients immunized >4 months prior to symptom onset (VE: 19%; 95% CI: -73-62%).
[h=4]DISCUSSION:[/h] Overall, the 2016 influenza vaccine showed good protection against laboratory-confirmed infection among general practice patients. Results by duration of vaccination suggest a significant decline in effectiveness during the 2016 influenza season, indicating immunization close to influenza season offered optimal protection.
Crown Copyright ? 2019. Published by Elsevier Ltd. All rights reserved.
[h=4]KEYWORDS:[/h] Case-control study; Influenza; Influenza vaccines; Test-negative design; Vaccine effectiveness
PMID: 30952499 DOI: 10.1016/j.vaccine.2019.02.027