tetano
Editor, Senior Moderator
J Infect Dis
. 2024 Dec 13:jiae615.
doi: 10.1093/infdis/jiae615. Online ahead of print. Estimating standard-dose and high-dose Fluzone vaccine efficacies for influenza A based on HAI titers
Savannah M Hammerton[SUP] 1 2 [/SUP], W Zane Billings[SUP] 1 2 [/SUP], Hayley Hemme[SUP] 1 [/SUP], Ted M Ross[SUP] 3 4 [/SUP], Ye Shen[SUP] 1 [/SUP], Andreas Handel[SUP] 1 2 [/SUP]
Affiliations
Background: The high-dose (HD) Fluzone influenza vaccine is currently recommended for individuals 65 and older, since it was shown in past studies to improve antibody responses and vaccine efficacy (VE) compared to a standard-dose (SD) formulation. Since influenza vaccines are frequently reformulated, monitoring any potential changes in VE is crucial. Traditional efficacy trials can be costly and time-consuming. Conducting immunogenicity studies with updated formulations and estimating VE with the resulting data is a more efficient way to assess these vaccines over time. Hemagglutination inhibition (HAI) titers are considered a reliable correlate of protection in influenza vaccine research and have previously been used to estimate VE.
Methods: We analyzed data from a human vaccine cohort who received either the SD or HD Fluzone split-inactivated influenza vaccine during influenza seasons 2013/14 to 2021/22. We used a previously developed statistical model to map pre- and post-vaccination HAI titers to protection probabilities, and computed differences in vaccine efficacy (VE) of the HD vaccine in older ( 65 years) populations compared to SD vaccines in the same age group and in younger (<65 years) adults.
Results: We found that for participants aged 65 and older, the HD vaccine generally improved the estimated VE across seasons. However, we also found that HD recipients often had a lower estimated VE than younger SD recipients.
Conclusions: While HD Fluzone vaccines lead to a small increase in estimated VE compared to SD in older adults, further increases in dose or other developments to improve VE should be considered.
Keywords: correlates of protection; high-dose vaccination; immunogenicity; older adults; statistical modeling; vaccine assessment; vaccine efficacy.
. 2024 Dec 13:jiae615.
doi: 10.1093/infdis/jiae615. Online ahead of print. Estimating standard-dose and high-dose Fluzone vaccine efficacies for influenza A based on HAI titers
Savannah M Hammerton[SUP] 1 2 [/SUP], W Zane Billings[SUP] 1 2 [/SUP], Hayley Hemme[SUP] 1 [/SUP], Ted M Ross[SUP] 3 4 [/SUP], Ye Shen[SUP] 1 [/SUP], Andreas Handel[SUP] 1 2 [/SUP]
Affiliations
- PMID: 39670611
- DOI: 10.1093/infdis/jiae615
Background: The high-dose (HD) Fluzone influenza vaccine is currently recommended for individuals 65 and older, since it was shown in past studies to improve antibody responses and vaccine efficacy (VE) compared to a standard-dose (SD) formulation. Since influenza vaccines are frequently reformulated, monitoring any potential changes in VE is crucial. Traditional efficacy trials can be costly and time-consuming. Conducting immunogenicity studies with updated formulations and estimating VE with the resulting data is a more efficient way to assess these vaccines over time. Hemagglutination inhibition (HAI) titers are considered a reliable correlate of protection in influenza vaccine research and have previously been used to estimate VE.
Methods: We analyzed data from a human vaccine cohort who received either the SD or HD Fluzone split-inactivated influenza vaccine during influenza seasons 2013/14 to 2021/22. We used a previously developed statistical model to map pre- and post-vaccination HAI titers to protection probabilities, and computed differences in vaccine efficacy (VE) of the HD vaccine in older ( 65 years) populations compared to SD vaccines in the same age group and in younger (<65 years) adults.
Results: We found that for participants aged 65 and older, the HD vaccine generally improved the estimated VE across seasons. However, we also found that HD recipients often had a lower estimated VE than younger SD recipients.
Conclusions: While HD Fluzone vaccines lead to a small increase in estimated VE compared to SD in older adults, further increases in dose or other developments to improve VE should be considered.
Keywords: correlates of protection; high-dose vaccination; immunogenicity; older adults; statistical modeling; vaccine assessment; vaccine efficacy.