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Evaluating SARS-CoV-2 Vaccine Effectiveness among Healthcare Personnel during Early Phase Vaccination


Healthcare personnel (HCP) are at risk of contracting SARS-CoV-2 during their interactions with patients who have confirmed, suspected or unrecognized infection of SARS-CoV-2. A key component of controlling the pandemic and protecting the U.S. healthcare workforce is deployment of a safe and effective SARS-CoV-2 vaccine. Evaluating the effectiveness soon after introduction of vaccine is essential to inform any revision of vaccine recommendations based on real-world experience in the early period of vaccine availability. Multiple vaccines are currently being evaluated in clinical trials. HCP in Connecticut began receiving vaccinations in mid-December of 2020. This early phase distribution of one or more vaccines provides an opportunity to evaluate the effectiveness of these vaccines in preventing symptomatic COVID-19 and to learn how these vaccines work in a real-world setting before widespread distribution to the general public but after favorable Phase III results are released.

Goals & Objectives

  1. Evaluate post-introduction effectiveness of a complete schedule of the SARS-CoV-2 vaccine in preventing laboratory-confirmed symptomatic COVID-19 among HCP.
  2. Evaluate post-introduction effectiveness of the SARS-CoV-2 vaccine in preventing severe disease among HCP with laboratory-confirmed symptomatic COVID-19;
  3. Evaluate effectiveness by HCP age groups and in subgroups with comorbidities;
  4. Evaluate effectiveness by various groups of HCP job categories and clinical practice settings;
  5. Evaluate effectiveness by vaccine product (if more than one product is in use) and for a single dose.


This activity is being conducted at all 10 EIP sites in the United States. In CT, the evaluation of the SARS-CoV-2 vaccine among healthcare personnel (HCP) began January 1, 2021. Hospitals participating in this project include CT facilities of a health system that is located in Connecticut. Yale EIP staff work with health system staff to identify HCP tested for SARS-CoV-2. HCP who test positive (cases) and negative (controls) for SARS-CoV-2 who agree to be contacted are interviewed to collect vaccination history, demographics, underlying medical conditions, roles in healthcare facilities, locations of work in the healthcare facility, locations of exposure (including community exposures), activities during exposures, PPE used during COVID-19 patient care, source control in patients, and duration of exposures.

Data stripped of personal identifiers will be shared with each participating facility as well as aggregated and shared with CDC for further analysis.


To come

Project Contact

Monica Brackney
Epidemiologist 3, Manager

Evaluating SARS-COV-2 Vaccine Effectiveness among Healthcare Personnel Staff

  • Addie Morris
  • Anisa Linton
  • Kelly Merritt