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. 2022 Dec 30;12(12):e069065.
doi: 10.1136/bmjopen-2022-069065.

Cohort Profile:The Danish National Cohort Study of Effectiveness and Safety of SARS-CoV-2 vaccines (ENFORCE)

Nina Breinholt Stærke  1   2 , Joanne Reekie  3 , Isik S Johansen  4   5 , Henrik Nielsen  6   7 , Thomas Benfield  8   9 , Lothar Wiese  10 , Ole S Søgaard  11   2 , Martin Tolstrup  11   2 , Kasper Karmark Iversen  9   12 , Britta Tarp  13 , Fredrikke Dam Larsen  11   2 , Lykke Larsen  4   5 , Susan Olaf Lindvig  4 , Inge Kristine Holden  4 , Mette Brouw Iversen  10 , Lene Surland Knudsen  10 , Kamille Fogh  12 , Marie Louise Jakobsen  3 , Anna Katrin Traytel  3 , Lars Ostergaard  11   2 , Jens Lundgren  3 ; ENFORCE Study Group
Affiliations

Cohort Profile:The Danish National Cohort Study of Effectiveness and Safety of SARS-CoV-2 vaccines (ENFORCE)

Nina Breinholt Stærke et al. BMJ Open. .

Abstract

Purpose: The ENFORCE cohort is a national Danish prospective cohort of adults who received a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine as part of the Danish National SARS-CoV-2 vaccination programme. It was designed to investigate the long-term effectiveness, safety and durability of SARS-CoV-2 vaccines used in Denmark.

Participants: A total of 6943 adults scheduled to receive a SARS-CoV-2 vaccine in the Danish COVID-19 vaccination programme were enrolled in the study prior to their first vaccination. Participants will be followed for a total of 2 years with five predetermined follow-up visits and additional visits in relation to any booster vaccination. Serology measurements are performed after each study visit. T-cell immunity is evaluated at each study visit for a subgroup of 699 participants. Safety information is collected from participants at visits following each vaccination. Data on hospital admissions, diagnoses, deaths and SARS-CoV-2 PCR results are collected from national registries throughout the study period. The median age of participants was 64 years (IQR 53-75), 56.6% were women and 23% were individuals with an increased risk of a serious course of COVID-19. A total of 340 (4.9%) participants tested positive for SARS-CoV-2 spike IgG at baseline.

Findings to date: Results have been published on risk factors for humoral hyporesponsiveness and non-durable response to SARS-CoV-2 vaccination, the risk of breakthrough infections at different levels of SARS-CoV-2 spike IgG by viral variant and on the antibody neutralising capacity against different SARS-CoV-2 variants following primary and booster vaccinations.

Future plans: The ENFORCE cohort will continuously generate studies investigating immunological response, effectiveness, safety and durability of the SARS-CoV-2 vaccines.

Trial registration number: NCT04760132.

Keywords: COVID-19; IMMUNOLOGY; Infection control.

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Conflict of interest statement

Competing interests: NBS declares to have served as investigator on studies sponsored by Pfizer, Gilead, Bavarian and Sanofi Pasteur. HN declares receiving a grant from Novo Nordisk Foundation and to have been on advisory boards for MSD and GSK. TB declares receipt of unrestricted research or travel grants from GSK, Pfizer, Gilead Sciences, MSD; and being principal investigator on trials conducted by Boehringer Ingelheim, Roche, Novartis, Kancera, Pfizer, MSD and Gilead; Board member on Pentabase, and advisory board member for MSD, Gilead, Pfizer, GSK, Janssen and AstraZeneca; consulting fees from GSK and Pfizer; receiving donation of study drug from Eli Lilly; and receiving honorarium for lectures from GSK, Pfizer, Gilead Sciences, Boehringer Ingelheim, AbbVie and AstraZeneca.

Figures

Figure 1
Figure 1
Schematic overview of the study visit schedule. Syringe icons signify SARS-CoV-2 vaccinations.
Figure 2
Figure 2
Cumulative number of participants enrolled over the inclusion period shown by vaccine type.
Figure 3
Figure 3
Flowchart of reasons for exclusion from the study.
Figure 4
Figure 4
Percentage of population testing positive and negative for SARS-CoV-2 IgG by means of the Wantai analysis at enrolment, shown for age groups and overall.
See this image and copyright information in PMC

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