tetano
Editor, Senior Moderator
Influenza Other Respir Viruses. 2017 Oct 25. doi: 10.1111/irv.12517. [Epub ahead of print]
[h=1]Both hemispheric influenza vaccine recommendations would have missed near half of the circulating viruses in Madagascar.[/h] Guillebaud J[SUP]1[/SUP], H?raud JM[SUP]1[/SUP], Razanajatovo NH[SUP]1[/SUP], Livinski AA[SUP]2[/SUP], Alonso WJ[SUP]3[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] Influenza immunization still poses a critical challenge globally and specifically for tropical regions due to their complex influenza circulation pattern. Tropical regions should select the WHO's Northern or Southern hemisphere recommended vaccine composition based on local surveillance. Analyses of influenza immunization effectiveness have neglected to account for the proportion of circulating viruses prevented from causing infection each year. We investigate this question for Madagascar, where influenza vaccines are not widely available.
[h=4]METHODS:[/h] 78 Malagasy influenza strains characterized from 2002 to 2014 were challenged with hypothetical scenarios in which the WHO's Northern and Southern hemisphere recommended vaccine compositions were provided to the population. Match between circulating and vaccine strains was determined by haemagglutination inhibition assays. Strain-specific positive matches were scored assuming 9 months of protection and scenarios incorporated vaccine delays from zero to five months.
[h=4]RESULTS:[/h] Malagasy influenza strains matched 54% and 44% respectively with the Northern and Southern hemisphere recommended vaccine strains when the vaccine was delivered as soon as available. The matching values further decreased when additional delivery and application delays were considered. Differences between recommended compositions were not statistically significant.
[h=4]CONCLUSION:[/h] Our results showed matching with the Northern hemisphere vaccine barely above 50%, even in the more favourable scenario. This suggests that if implemented, routine influenza vaccines would not protect against half of the influenza strains circulating in any epidemic season of Madagascar. We suggest that this limitation in influenza vaccine efficacy deserves greater attention, and should be considered in cost/benefit analyses of national influenza immunization programs. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
[h=4]KEYWORDS:[/h] Efficacy; Influenza; Madagascar; Match; Seasonality; Timing; Vaccination
PMID: 29067783 DOI: 10.1111/irv.12517
[h=1]Both hemispheric influenza vaccine recommendations would have missed near half of the circulating viruses in Madagascar.[/h] Guillebaud J[SUP]1[/SUP], H?raud JM[SUP]1[/SUP], Razanajatovo NH[SUP]1[/SUP], Livinski AA[SUP]2[/SUP], Alonso WJ[SUP]3[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] Influenza immunization still poses a critical challenge globally and specifically for tropical regions due to their complex influenza circulation pattern. Tropical regions should select the WHO's Northern or Southern hemisphere recommended vaccine composition based on local surveillance. Analyses of influenza immunization effectiveness have neglected to account for the proportion of circulating viruses prevented from causing infection each year. We investigate this question for Madagascar, where influenza vaccines are not widely available.
[h=4]METHODS:[/h] 78 Malagasy influenza strains characterized from 2002 to 2014 were challenged with hypothetical scenarios in which the WHO's Northern and Southern hemisphere recommended vaccine compositions were provided to the population. Match between circulating and vaccine strains was determined by haemagglutination inhibition assays. Strain-specific positive matches were scored assuming 9 months of protection and scenarios incorporated vaccine delays from zero to five months.
[h=4]RESULTS:[/h] Malagasy influenza strains matched 54% and 44% respectively with the Northern and Southern hemisphere recommended vaccine strains when the vaccine was delivered as soon as available. The matching values further decreased when additional delivery and application delays were considered. Differences between recommended compositions were not statistically significant.
[h=4]CONCLUSION:[/h] Our results showed matching with the Northern hemisphere vaccine barely above 50%, even in the more favourable scenario. This suggests that if implemented, routine influenza vaccines would not protect against half of the influenza strains circulating in any epidemic season of Madagascar. We suggest that this limitation in influenza vaccine efficacy deserves greater attention, and should be considered in cost/benefit analyses of national influenza immunization programs. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
[h=4]KEYWORDS:[/h] Efficacy; Influenza; Madagascar; Match; Seasonality; Timing; Vaccination
PMID: 29067783 DOI: 10.1111/irv.12517