Evidence map›Paper›PMID 40830930›Full record

ArticleBMC infectious diseases2025

Risk factors and effectiveness of vaccination for nosocomial SARS-CoV-2 acquisition throughout the SARS-CoV-2 pandemic.

Nishi Dave, Suzanne D van der Werff, Daniel Sjöholm, Johan Zetterqvist, Pontus Nauclér

Abstract read
In one paragraph

Article in BMC infectious diseases, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Nishi DaveDepartment of Medicine, Solna, Division of Infectious Diseases, Karolinska Institutet, Stockholm, Sweden.
Suzanne D van der WerffDepartment of Medicine, Solna, Division of Infectious Diseases, Karolinska Institutet, Stockholm, Sweden.
Daniel SjöholmDepartment of Medicine, Solna, Clinical Epidemiology Division, Karolinska Institutet, Stockholm, Sweden.
Johan ZetterqvistDepartment of Medicine, Solna, Division of Infectious Diseases, Karolinska Institutet, Stockholm, Sweden.
Pontus NauclérDepartment of Medicine, Solna, Division of Infectious Diseases, Karolinska Institutet, Stockholm, Sweden. pontus.naucler@ki.se.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundStudies elucidating the risk factors for nosocomial SARS-CoV-2 infections or assessing effectiveness of vaccination on acquisition prevention throughout the pandemic period are scarce. Here, we aimed to identify individual- and care-related risk factors and study the association between vaccination and risk of infection for nosocomial SARS-CoV-2 infections.

methodsWe performed a nested case-control study of patients aged ≥ 18 years hospitalised in Region Stockholm, between 1 March 2020 -15 November 2023. Each case was matched to up to 10 controls, on admission date, time period, and length of stay. Individual factors of sex, age, region of birth, education level, comorbidities and care-related factors such as number of transfers during care episode, surgery status, type of hospital unit and hospitals in the region were assessed. Vaccine effectiveness was assessed for number of doses and time since last vaccination. Conditional logistic regression was used to calculate odds ratio for risk factors and vaccine effectiveness.

resultsAmong 2711 cases and 27,065 matched controls, older age (90 + years: 4.11 [2.71-6.23]), male sex (1.11 [1.02-1.21]) and chronic lung disease (1.25 [1.12 to 1.40]) were associated with increased odds of nosocomial infection. Among care-related factors, admission to geriatric hospital units (1.54 [1.26-1.89]) and increased number of transfers (2 + transfers: 2.48 [1.89-2.34]) were associated with higher odds. Overall, while vaccination with 2 or more doses and any time since last dose compared to being unvaccinated was associated with lower odds of infections, we observed that vaccination with 3 doses (aOR: 0.55, 95% CI: 0.46-0.67), and those with their latest dose administered within the last 3 months had the lowest odds of infection (aOR: 0.48, 95% CI: 0.39 to 0.59).

conclusionsWe demonstrated that vaccination is effective in reducing the risk of nosocomial SARS-CoV-2 infection, and preventive measures during early phases of pandemics should focus on high-risk patient groups. Risk of infection can be further reduced by focusing on high-risk areas within hospital settings and by reducing patient transfers during their care episode.

Indexed as

COVID-19COVID-19 VaccinesCross InfectionSARS-CoV-2VaccinationVaccine EfficacyAdultAgedAged, 80 and overCase-Control StudiesFemaleHumansMaleMiddle AgedRisk FactorsSwedenCOVID-19 VaccinesNested case-controlNosocomial infectionRisk factorsSARS-CoV-2Vaccine effectiveness

Identifiers

PMID40830930
PMCPMC12366111

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.