tetano
Editor, Senior Moderator
Vaccine. 2019 Sep 11. pii: S0264-410X(19)31145-4. doi: 10.1016/j.vaccine.2019.08.069. [Epub ahead of print]
[h=1]Modelling of optimal timing for influenza vaccination as a function of intraseasonal waning of immunity and vaccine coverage.[/h] Costantino V[SUP]1[/SUP], MacIntyre CR[SUP]2[/SUP], Trent M[SUP]3[/SUP].
[h=3]Author information[/h] 1 Biosecurity Program, Kirby Institute, Faculty of Medicine, The University of New South Wales, Sydney, Australia. Electronic address: v.costantino@unsw.edu.au. 2 Biosecurity Program, Kirby Institute, Faculty of Medicine, The University of New South Wales, Sydney, Australia; College of Public Service and Community Solutions, Arizona State University, Arizona, USA. Electronic address: r.macintyre@unsw.edu.au. 3 Biosecurity Program, Kirby Institute, Faculty of Medicine, The University of New South Wales, Sydney, Australia. Electronic address: mallory.trent@unsw.edu.au.
[h=3]Abstract[/h] The influenza season in Australia usually peaks in August. Vaccination is recommended beginning in March-April. Recent studies suggest that vaccine effectiveness may wane over a given influenza season, leading to reduced effectiveness at the peak of the season. We aimed to quantify how changes in timing of influenza vaccination and declining vaccine coverage could change the percentages of prevented cases. Results from a systematic review were used to inform calculation of a waning function over time from vaccination. Age specific notification data and vaccine effectiveness and coverage estimates from 2007 to 2016 (2009 influenza pandemic year excluded) were used to model a new notification series where vaccine effectiveness is shifted in time to account for delayed vaccination by month from March to August. A sensitivity analysis was done on possible vaccine coverage changes and considering time gap between vaccine uptake and recommendation. Delaying vaccination from March to end of May prevents more cases over a season, but the variation in cases prevented by month of vaccination is not large. If delaying vaccination results in missed or forgotten vaccination and decrease coverage, delaying vaccination could have a net negative impact. Furthermore, considering a time gap between recommendation and uptake, earlier recommendation is more effective in preventing cases. The results are sensitive to assumptions of intra-seasonal waning of effectiveness. More research is required on intra-seasonal vaccine effectiveness waning and the effect of delayed vaccination on overall uptake to inform any potential changes to current vaccine scheduling recommendations.
Copyright ? 2019 Elsevier Ltd. All rights reserved.
[h=4]KEYWORDS:[/h] Influenza control; Outbreak response; Vaccination timing; Vaccine effectiveness; Vaccine efficacy waning
PMID: 31521411 DOI: 10.1016/j.vaccine.2019.08.069
[h=1]Modelling of optimal timing for influenza vaccination as a function of intraseasonal waning of immunity and vaccine coverage.[/h] Costantino V[SUP]1[/SUP], MacIntyre CR[SUP]2[/SUP], Trent M[SUP]3[/SUP].
[h=3]Author information[/h] 1 Biosecurity Program, Kirby Institute, Faculty of Medicine, The University of New South Wales, Sydney, Australia. Electronic address: v.costantino@unsw.edu.au. 2 Biosecurity Program, Kirby Institute, Faculty of Medicine, The University of New South Wales, Sydney, Australia; College of Public Service and Community Solutions, Arizona State University, Arizona, USA. Electronic address: r.macintyre@unsw.edu.au. 3 Biosecurity Program, Kirby Institute, Faculty of Medicine, The University of New South Wales, Sydney, Australia. Electronic address: mallory.trent@unsw.edu.au.
[h=3]Abstract[/h] The influenza season in Australia usually peaks in August. Vaccination is recommended beginning in March-April. Recent studies suggest that vaccine effectiveness may wane over a given influenza season, leading to reduced effectiveness at the peak of the season. We aimed to quantify how changes in timing of influenza vaccination and declining vaccine coverage could change the percentages of prevented cases. Results from a systematic review were used to inform calculation of a waning function over time from vaccination. Age specific notification data and vaccine effectiveness and coverage estimates from 2007 to 2016 (2009 influenza pandemic year excluded) were used to model a new notification series where vaccine effectiveness is shifted in time to account for delayed vaccination by month from March to August. A sensitivity analysis was done on possible vaccine coverage changes and considering time gap between vaccine uptake and recommendation. Delaying vaccination from March to end of May prevents more cases over a season, but the variation in cases prevented by month of vaccination is not large. If delaying vaccination results in missed or forgotten vaccination and decrease coverage, delaying vaccination could have a net negative impact. Furthermore, considering a time gap between recommendation and uptake, earlier recommendation is more effective in preventing cases. The results are sensitive to assumptions of intra-seasonal waning of effectiveness. More research is required on intra-seasonal vaccine effectiveness waning and the effect of delayed vaccination on overall uptake to inform any potential changes to current vaccine scheduling recommendations.
Copyright ? 2019 Elsevier Ltd. All rights reserved.
[h=4]KEYWORDS:[/h] Influenza control; Outbreak response; Vaccination timing; Vaccine effectiveness; Vaccine efficacy waning
PMID: 31521411 DOI: 10.1016/j.vaccine.2019.08.069