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Waning protection after vaccination and prior infection against COVID-19-related mortality over 18 months

Dietler, Dominik LU orcid ; Kahn, Fredrik LU ; Inghammar, Malin LU and Björk, Jonas LU (2023) In Clinical Microbiology and Infection 29(12). p.1573-1580
Abstract

OBJECTIVES: Evidence on waning patterns in protection from vaccine-induced, infection-induced, and hybrid immunity against death is scarce. The aim of this study is to assess the temporal trends in protection against mortality.

METHODS: Population-based case-control study nested in the total population of Scania Region, Sweden using individual-level registry data of COVID-19-related deaths (<30 days after positive SARS-CoV-2 test) between 27 December 2020 and 3 June 2022. Controls were matched for age, sex, and index date. Conditional logistic regression was used to estimate the preventable fraction (PF) from vaccination (PF
vac corresponding to vaccine effectiveness; ≥2 vaccine doses vs. 0 doses), prior infection (PF ... (More)

OBJECTIVES: Evidence on waning patterns in protection from vaccine-induced, infection-induced, and hybrid immunity against death is scarce. The aim of this study is to assess the temporal trends in protection against mortality.

METHODS: Population-based case-control study nested in the total population of Scania Region, Sweden using individual-level registry data of COVID-19-related deaths (<30 days after positive SARS-CoV-2 test) between 27 December 2020 and 3 June 2022. Controls were matched for age, sex, and index date. Conditional logistic regression was used to estimate the preventable fraction (PF) from vaccination (PF
vac corresponding to vaccine effectiveness; ≥2 vaccine doses vs. 0 doses), prior infection (PF
inf), and hybrid immunity (PF
hybrid). PF was calculated as one minus odds ratio. Models were adjusted for comorbidities, long-term care facility residence, prior infection (for PF
vac), country of birth, socio-economic conditions, and time since last vaccination (for PF
inf).

RESULTS: In total, 14 936 individuals (1440 COVID-19-related deaths and 13 496 controls) were included in the case-control analyses (45% females, median age: 84 years). PF
vac was above 90% during the first month after vaccination, regardless of the number of vaccine doses. After 6 months, PF
vac of two doses waned to 34% (95% CI: -30% to 66%). PF
inf for people surviving a SARS-CoV-2 infection waned from 88% (-16% to 99%) 3 months after infection to 62% (34-79%) after 9 months. No differences in waning patterns in PF
vac were seen between virus variants, gender, and age.

DISCUSSION: Given the waning of protection against death, continuous surveillance of population immunity status, particularly among the most vulnerable population groups, could help to further fine-tune vaccination recommendations.

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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Clinical Microbiology and Infection
volume
29
issue
12
pages
1573 - 1580
publisher
Wiley-Blackwell
external identifiers
  • scopus:85169511640
  • pmid:37580016
ISSN
1469-0691
DOI
10.1016/j.cmi.2023.08.007
project
Improved preparedness for future pandemics and other health crises through large-scale disease surveillance
language
English
LU publication?
yes
id
76df4c4f-5fd6-4e28-a36f-5d624e9f2613
date added to LUP
2023-10-12 15:38:31
date last changed
2024-04-19 02:18:22
@article{76df4c4f-5fd6-4e28-a36f-5d624e9f2613,
  abstract     = {{<p>OBJECTIVES: Evidence on waning patterns in protection from vaccine-induced, infection-induced, and hybrid immunity against death is scarce. The aim of this study is to assess the temporal trends in protection against mortality.</p><p>METHODS: Population-based case-control study nested in the total population of Scania Region, Sweden using individual-level registry data of COVID-19-related deaths (&lt;30 days after positive SARS-CoV-2 test) between 27 December 2020 and 3 June 2022. Controls were matched for age, sex, and index date. Conditional logistic regression was used to estimate the preventable fraction (PF) from vaccination (PF<br>
 vac corresponding to vaccine effectiveness; ≥2 vaccine doses vs. 0 doses), prior infection (PF <br>
 inf), and hybrid immunity (PF<br>
 hybrid). PF was calculated as one minus odds ratio. Models were adjusted for comorbidities, long-term care facility residence, prior infection (for PF<br>
 vac), country of birth, socio-economic conditions, and time since last vaccination (for PF<br>
 inf).<br>
 </p><p>RESULTS: In total, 14 936 individuals (1440 COVID-19-related deaths and 13 496 controls) were included in the case-control analyses (45% females, median age: 84 years). PF<br>
 vac was above 90% during the first month after vaccination, regardless of the number of vaccine doses. After 6 months, PF<br>
 vac of two doses waned to 34% (95% CI: -30% to 66%). PF<br>
 inf for people surviving a SARS-CoV-2 infection waned from 88% (-16% to 99%) 3 months after infection to 62% (34-79%) after 9 months. No differences in waning patterns in PF<br>
 vac were seen between virus variants, gender, and age.<br>
 </p><p>DISCUSSION: Given the waning of protection against death, continuous surveillance of population immunity status, particularly among the most vulnerable population groups, could help to further fine-tune vaccination recommendations.</p>}},
  author       = {{Dietler, Dominik and Kahn, Fredrik and Inghammar, Malin and Björk, Jonas}},
  issn         = {{1469-0691}},
  language     = {{eng}},
  month        = {{08}},
  number       = {{12}},
  pages        = {{1573--1580}},
  publisher    = {{Wiley-Blackwell}},
  series       = {{Clinical Microbiology and Infection}},
  title        = {{Waning protection after vaccination and prior infection against COVID-19-related mortality over 18 months}},
  url          = {{http://dx.doi.org/10.1016/j.cmi.2023.08.007}},
  doi          = {{10.1016/j.cmi.2023.08.007}},
  volume       = {{29}},
  year         = {{2023}},
}