tetano
Editor, Senior Moderator
Expert Rev Vaccines
. 2024 Jan-Dec;23(1):380-388.
doi: 10.1080/14760584.2024.2331073. Epub 2024 Mar 18. Waning intra-season vaccine effectiveness against influenza A(H3N2) underlines the need for more durable protection
Alexander Domnich[SUP] 1 [/SUP], Andrea Orsi[SUP] 1 2 3 [/SUP], Alessio Signori[SUP] 2 [/SUP], Maria Chironna[SUP] 4 [/SUP], Ilaria Manini[SUP] 3 5 [/SUP], Christian Napoli[SUP] 6 [/SUP], Caterina Rizzo[SUP] 7 [/SUP], Donatella Panatto[SUP] 2 3 [/SUP], Giancarlo Icardi[SUP] 1 2 3 [/SUP]
Affiliations
Background: The question of whether influenza vaccine effectiveness (VE) wanes over the winter season is still open and some contradictory findings have been reported. This study investigated the possible decline in protection provided by the available influenza vaccines.
Research design and methods: An individual-level pooled analysis of six test-negative case-control studies conducted in Italy between the 2018/2019 and 2022/2023 seasons was performed. Multivariable logistic regression analyses were performed to estimate weekly change in the odds of testing positive for influenza 14 days after vaccination.
Results: Of 6490 patients included, 1633 tested positive for influenza. Each week that had elapsed since vaccination was associated with an increase in the odds of testing positive for any influenza (4.9%; 95% CI: 2.0-8.0%) and for A(H3N2) (6.5%; 95% CI: 2.9-10.3%). This decline in VE was, however, significant only in children and older adults. A similar increase in the odds of testing positive was seen when the dataset was restricted to vaccinees only. Conversely, VE waning was less evident for A(H1N1)pdm09 or B strains.
Conclusions: Significant waning of VE, especially against influenza A(H3N2), may be one of the factors associated with suboptimal end-of-season VE. Next-generation vaccines should provide more durable protection against A(H3N2).
Keywords: A(H3N2) subtype; Influenza; influenza vaccines; vaccine effectiveness; waning.
. 2024 Jan-Dec;23(1):380-388.
doi: 10.1080/14760584.2024.2331073. Epub 2024 Mar 18. Waning intra-season vaccine effectiveness against influenza A(H3N2) underlines the need for more durable protection
Alexander Domnich[SUP] 1 [/SUP], Andrea Orsi[SUP] 1 2 3 [/SUP], Alessio Signori[SUP] 2 [/SUP], Maria Chironna[SUP] 4 [/SUP], Ilaria Manini[SUP] 3 5 [/SUP], Christian Napoli[SUP] 6 [/SUP], Caterina Rizzo[SUP] 7 [/SUP], Donatella Panatto[SUP] 2 3 [/SUP], Giancarlo Icardi[SUP] 1 2 3 [/SUP]
Affiliations
- PMID: 38494919
- DOI: 10.1080/14760584.2024.2331073
Background: The question of whether influenza vaccine effectiveness (VE) wanes over the winter season is still open and some contradictory findings have been reported. This study investigated the possible decline in protection provided by the available influenza vaccines.
Research design and methods: An individual-level pooled analysis of six test-negative case-control studies conducted in Italy between the 2018/2019 and 2022/2023 seasons was performed. Multivariable logistic regression analyses were performed to estimate weekly change in the odds of testing positive for influenza 14 days after vaccination.
Results: Of 6490 patients included, 1633 tested positive for influenza. Each week that had elapsed since vaccination was associated with an increase in the odds of testing positive for any influenza (4.9%; 95% CI: 2.0-8.0%) and for A(H3N2) (6.5%; 95% CI: 2.9-10.3%). This decline in VE was, however, significant only in children and older adults. A similar increase in the odds of testing positive was seen when the dataset was restricted to vaccinees only. Conversely, VE waning was less evident for A(H1N1)pdm09 or B strains.
Conclusions: Significant waning of VE, especially against influenza A(H3N2), may be one of the factors associated with suboptimal end-of-season VE. Next-generation vaccines should provide more durable protection against A(H3N2).
Keywords: A(H3N2) subtype; Influenza; influenza vaccines; vaccine effectiveness; waning.