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Influenza vaccine effectiveness in patients hospitalized with severe acute respiratory infection in Lithuania during the 2019-2020 influenza season : a test negative case - control study

Vaikutyte, Roberta ; Kuliese, Monika ; Mickiene, Aukse ; Jancoriene, Ligita ; Zablockiene, Birute and Gefenaite, Giedre LU orcid (2023) In Virology Journal 20(1).
Abstract

BACKGROUND: Influenza is a contagious viral airborne disease that adds to the clinical and economic burden on the healthcare system. It could be prevented substantially by seasonal influenza vaccination. Seasonal influenza vaccine effectiveness (SIVE) varies a lot and should therefore be monitored. This report aims to update age-stratified SIVE estimates among patients hospitalized due to severe acute respiratory infection (SARI) during the 2019-2020 influenza season.

METHODS: We performed a test-negative case-control study between December 2019 and April 2020 influenza season. We estimated SIVE and its 95% confidence intervals (95% CI) with logistic regression as (1-odds ratio)*100%. The models were adjusted for covariates that... (More)

BACKGROUND: Influenza is a contagious viral airborne disease that adds to the clinical and economic burden on the healthcare system. It could be prevented substantially by seasonal influenza vaccination. Seasonal influenza vaccine effectiveness (SIVE) varies a lot and should therefore be monitored. This report aims to update age-stratified SIVE estimates among patients hospitalized due to severe acute respiratory infection (SARI) during the 2019-2020 influenza season.

METHODS: We performed a test-negative case-control study between December 2019 and April 2020 influenza season. We estimated SIVE and its 95% confidence intervals (95% CI) with logistic regression as (1-odds ratio)*100%. The models were adjusted for covariates that changed the unadjusted SIVE by ≥ 10%.

RESULTS: Among 84 participants, 32 (38.1%) were influenza positive, mostly with A(H1N1)pdm09 (25 cases; 78.1%). SIVE against any influenza adjusted for age and heart disease was 39.2% (95% CI: -119.3%, 83.1%). Age-stratified point estimates adjusted for heart diseases indicated different SIVE, and were 64.0% (95% CI: -309.2%, 96.8%) and 21.6% (95% CI: -252.2%, 82.6%) for 18-64 and ≥ 65 year-old participants, respectively.

CONCLUSIONS: The point estimates suggested low to moderate SIVE against any influenza among hospitalized 18-64-year-old SARI participants, while low estimates were found in the ≥ 65-year-old group. Although broad SIVE confidence intervals indicate a small sample size and therefore the results can serve only as indicatory, they are in line with the estimates reported by other studies during the 2019-2020 season.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Humans, Aged, Adolescent, Young Adult, Adult, Middle Aged, Influenza, Human/epidemiology, Influenza Vaccines, Lithuania, Influenza A Virus, H1N1 Subtype, Case-Control Studies, Seasons, Vaccine Efficacy, Influenza B virus, Vaccination, Influenza A Virus, H3N2 Subtype
in
Virology Journal
volume
20
issue
1
article number
67
pages
5 pages
publisher
BioMed Central (BMC)
external identifiers
  • pmid:37046288
  • scopus:85152337708
ISSN
1743-422X
DOI
10.1186/s12985-023-02015-0
project
Infectious diseases surveillance, vaccine effectiveness and determinants of acceptance
language
English
LU publication?
yes
additional info
© 2023. The Author(s).
id
acd36f2d-dfc5-42ad-b857-f819b5d581c4
date added to LUP
2023-04-20 13:05:53
date last changed
2025-04-20 07:19:19
@article{acd36f2d-dfc5-42ad-b857-f819b5d581c4,
  abstract     = {{<p>BACKGROUND: Influenza is a contagious viral airborne disease that adds to the clinical and economic burden on the healthcare system. It could be prevented substantially by seasonal influenza vaccination. Seasonal influenza vaccine effectiveness (SIVE) varies a lot and should therefore be monitored. This report aims to update age-stratified SIVE estimates among patients hospitalized due to severe acute respiratory infection (SARI) during the 2019-2020 influenza season.</p><p>METHODS: We performed a test-negative case-control study between December 2019 and April 2020 influenza season. We estimated SIVE and its 95% confidence intervals (95% CI) with logistic regression as (1-odds ratio)*100%. The models were adjusted for covariates that changed the unadjusted SIVE by ≥ 10%.</p><p>RESULTS: Among 84 participants, 32 (38.1%) were influenza positive, mostly with A(H1N1)pdm09 (25 cases; 78.1%). SIVE against any influenza adjusted for age and heart disease was 39.2% (95% CI: -119.3%, 83.1%). Age-stratified point estimates adjusted for heart diseases indicated different SIVE, and were 64.0% (95% CI: -309.2%, 96.8%) and 21.6% (95% CI: -252.2%, 82.6%) for 18-64 and ≥ 65 year-old participants, respectively.</p><p>CONCLUSIONS: The point estimates suggested low to moderate SIVE against any influenza among hospitalized 18-64-year-old SARI participants, while low estimates were found in the ≥ 65-year-old group. Although broad SIVE confidence intervals indicate a small sample size and therefore the results can serve only as indicatory, they are in line with the estimates reported by other studies during the 2019-2020 season.</p>}},
  author       = {{Vaikutyte, Roberta and Kuliese, Monika and Mickiene, Aukse and Jancoriene, Ligita and Zablockiene, Birute and Gefenaite, Giedre}},
  issn         = {{1743-422X}},
  keywords     = {{Humans; Aged; Adolescent; Young Adult; Adult; Middle Aged; Influenza, Human/epidemiology; Influenza Vaccines; Lithuania; Influenza A Virus, H1N1 Subtype; Case-Control Studies; Seasons; Vaccine Efficacy; Influenza B virus; Vaccination; Influenza A Virus, H3N2 Subtype}},
  language     = {{eng}},
  month        = {{04}},
  number       = {{1}},
  publisher    = {{BioMed Central (BMC)}},
  series       = {{Virology Journal}},
  title        = {{Influenza vaccine effectiveness in patients hospitalized with severe acute respiratory infection in Lithuania during the 2019-2020 influenza season : a test negative case - control study}},
  url          = {{http://dx.doi.org/10.1186/s12985-023-02015-0}},
  doi          = {{10.1186/s12985-023-02015-0}},
  volume       = {{20}},
  year         = {{2023}},
}