Mexican Social Security Institute (IMSS) Pandemic Workforce Administrative Cohort (IMPACT): design and descriptive estimates of surveillance-detected COVID-19 outcomes and primary-series vaccination coverage.

Authors

Edgar Ortiz-Brizuela, Mireille E Schnitzer, Denis Talbot, Gabriel Alejandro Real Ornelas, Rebeca Velasco Reyna, Mauricio Hernandez-Avila, Mabel Carabali

Published in

BMJ public health. Volume 4. Issue 4. Pages e004581. Epub Oct 20, 2026.

Abstract

The COVID-19 pandemic placed unprecedented strain on health systems and their workers. In Mexico, the health-system workforce faced this crisis amid major population health, socioeconomic and institutional constraints. Despite these challenges, no population-level research platform existed to support pandemic-related research on this occupational group. In this study, we describe the design of the Mexican Social Security Institute (IMSS) Pandemic Workforce Administrative Cohort (IMPACT) and, as its first application, characterise primary-series vaccination coverage and surveillance-detected COVID-19 outcomes.
Using IMSS payroll records, we identified workers employed during the pandemic and linked this roster to additional real-world data sources. Guided by relevant literature, we operationalised variables for baseline characteristics, vaccination status and surveillance-detected COVID-19 outcomes. We defined two analytical cohorts from these linked data (follow-up end: 9 May 2023): a closed cohort comprising workers already employed at pandemic onset and an open cohort that additionally included subsequent hires. Vaccination was assessed in the closed cohort whereas COVID-19 outcomes were assessed in both. Analyses were conducted overall and stratified by work-unit type, job category, department and geography.
In the closed cohort (n=434 655), first-dose and full-series coverage exceeded 70% by days 123 and 169 of the rollout, reaching 93.4% (95% CI 93.3% to 93.5%) and 84.0% (95% CI 83.8% to 84.1%) by follow-up end. Over this period, cumulative incidence was 55.4% (95% CI 55.2% to 55.5%) for infection, 0.99% (95% CI 0.96% to 1.02%) for hospitalisation and 0.22% (95% CI 0.21% to 0.24%) for death. In the open cohort (n=506 995), incidence rates per 100 000 person-days were 60.7 (95% CI 60.6 to 60.9) for infection, 0.80 (95% CI 0.77 to 0.83) for hospitalisation and 0.18 (95% CI 0.15 to 0.20) for death. Unstandardised estimates varied substantially across strata.
Among workers employed at pandemic onset, vaccination coverage was high, particularly for first doses. Although surveillance-detected infection was common, severe outcomes were infrequently recorded. Stratified analyses identified vaccination gaps and high-burden strata warranting further investigation. IMPACT provides a valuable platform for policy-relevant research into this workforce.

PMID:
42948618
Bibliographic data and abstract were imported from PubMed on 28 Oct 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.