Current and Past SARS-CoV-2 Infection and COVID-19 in Healthcare With Regard to Vaccinations

Studies of Ongoing and Completed SARS-CoV-2 Infection (Which Causes COVID-19) Within the Healthcare in Stockholm County, With Regard to Vaccinations.

To investigate the incidence of SARS-CoV-2 infections after vaccination, to monitor the development of SARS-CoV-2 antibody levels after vaccination and to compare this in relation to both previous health & disease, previous antibody responses and in relation to future disease occurring after vaccination.

Study Overview

• Status: Active, not recruiting
• Conditions: SARS-CoV 2
• Intervention / Treatment: Diagnostic test: SARS-CoV2 antibody measurement

Detailed Description

The purpose of the study is to analyze the effect of and possible side effects of SARS-CoV2 vaccinations in the cohort study where data on sick leave, SARS-Cov2 infections and SARS-CoV2 antibody levels are well documented even before vaccination.

The main outcome measures are the presence of SARS-CoV-2 (ongoing infection) and the presence of antibodies to SARS-CoV-2.

For the vaccination effect, the factors that are primarily associated with protection against infection are analyzed, such as age, sex, workplace, antibody response to SARS-CoV-2 and vaccination date.

The analyzes are planned to be performed with multivariate logistic regression with Relative Risk as the outcome measure.

Data from the analysis of virus antibodies are planned to be performed divided into whether low, medium or high levels of antibodies occur, with the same analysis for possible association with the factors listed above.

• Study Type: Observational
• Enrollment (Estimated): 10000

Contacts and Locations

Study Locations

• Sweden
  • Stockholm, Sweden, 141 86
    • Karolinska University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 99 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

-Personnel within healthcare in Stockholm County who have previously participated in a study on SARS-CoV-2 infection within healthcare in Stockholm County and who are offered a vaccine against Covid-19.

Description

Inclusion Criteria:

• Study participant who agreed to be included in the study "Studies of ongoing and completed SARS-CoV-2 infection (which causes COVID-19) within the healthcare in Stockholm County".
• Study participant who has received or will receive vaccine against Covid-19 and who gives new written consent to the study "Studies of ongoing and completed SARS-CoV-2 infection (which causes COVID-19) within the healthcare in Stockholm County, with regard to vaccinations".

Exclusion Criteria:

• those who have not given informed consent to participate in the study In this study, no initiative is taken for vaccination. The vaccinations are carried out by the healthcare system and of course follow the established exclusion and inclusion criteria for the approved vaccines. All persons who have received the vaccine and who give written consent are eligible to be included in the study.

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Study cohort; Personnel in health and care in Stockholm County, who have previously participated in a study where data on sick leave, SARS-Cov2 infections and SARS-CoV2 antibody levels were collected and documented form the study cohort.	Diagnostic test: SARS-CoV2 antibody measurement; Blood samples for serology, collected immediately prior to and five to ten weeks after vaccination against SARS-CoV2, to be analyzed for the presence of SARS-CoV-2 antibodies.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
SARS-CoV-2 infection	Characterized by whether they are asymptomatic infections or sick leave-requiring infections.	24 months post primary vaccination

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
SARS-CoV-2 antibody induction	Antibodies will be characterized in terms of antibody levels, which SARS-CoV-2 antigen to which the response is directed and whether the antibodies are protective or not.	24 months post primary vaccination

Collaborators and Investigators

• Sponsor: Karolinska Institutet
• Collaborators: Karolinska University Hospital
• Investigators: Principal Investigator: Joakim Dillner, MD, PhD, Karolinska Institutet

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2021
• Primary Completion (Actual): March 31, 2023
• Study Completion (Estimated): December 31, 2025

Study Registration Dates

• First Submitted: April 19, 2021
• First Submitted That Met QC Criteria: April 19, 2021
• First Posted (Actual): April 21, 2021

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: March 18, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Respiratory Tract Infections; Infections; RNA Virus Infections; Virus Diseases; Respiratory Tract Diseases; Lung Diseases; Pneumonia, Viral; Pneumonia; Coronavirus Infections; Coronaviridae Infections; Nidovirales Infections; COVID-19; Immunologic Factors; Physiological Effects of Drugs; Antibodies
• Other Study ID Numbers: Covid19_7

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: We have yet to determine whether the IPD will be available for other researchers.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No