Monitoring of COVID-19 Seroprevalence Among GHdC Staff Members

Monitoring of COVID-19 Seroprevalence Among GHdC Staff Members: Protocol for an Interventional Cohort Study in 2020-2021

Grand Hôpital de Charleroi (GHdC) had to organize the vaccination of its staff in December 2021 against SARS-CoV-2.On the sidelines of this vaccination campaign, the management committee agreed to document the knowledge of the SARS-CoV-2 serology of all the staff of the establishment before this vaccination campaign, as well as a few weeks after vaccination. In November 2021, the Belgian government decided to offer a third dose of vaccine against SARS-CoV-2 virus. The GHdC managment committee has agreed to continue monitoring SARS-CoV-2 serology for members who receive their third dose of vaccine.

Grand Hôpital de Charleroi (GHdC) staff were exposed to the risk of SARS-CoV-2 infection during the first half of 2020: a seroprevalence survey, conducted in the summer of 2020, after the "first wave" of the epidemic, and before the "second wave", thus revealed a significant seroprevalence because of its exposure. This study, because of its high participation rate, also showed the sustained interest of the agents in knowing their serology, either for personal reasons, or for the purposes of recognition as an occupational disease. The GHdC decided in December 2020 to organize as soon as possible the vaccination of its salaried and self-employed employees who wish to take advantage of this opportunity. On the sidelines of this vaccination campaign, the management committee agreed to document the knowledge of the SARS-Cov-2 serology of all the staff of the establishment before this vaccination campaign, as well as a few weeks after vaccination. This knowledge must better organize the disease prevention strategy, both with regard to the staff themselves and the patients for whom they are called upon to treat. When the Belgian government decided in November 2021 to offer a third dose of vaccine and start it up in hospitals, the GHdC managment committee has agreed to continue monitoring SARS-CoV-2 serology for members who agree to receive their third dose of vaccine.

Group 1 : participants who did not agree to receive a SARS-CoV-2 vaccine in the first Belgian campaing but who agreed to perform a serological test against COVID-19. Groups of participants who agree to receive a SARS-CoV-2 vaccine at different specific times determined by the Belgian State for workers at the Grand Hôpital de Charleroi. Parallel study of immunity to SARS-CoV-2 among staff members.

Participant who does not wish to be vaccinated against the SARS-CoV-2 virus and who wishes to perform the serological test during the vaccination campaign and the second 12-14 weeks after the first serological test.

Participant who has received his first dose of vaccine and who performs his serological test when he receives the second dose of vaccine against the SARS-CoV-2 virus to determine his immunity. The second serological test will be done 12 to 14 weeks after the second dose of the SARS-CoV-2 vaccine to determine its immunity.

Participant who performed the serological test before the first dose of vaccine and 12 to 14 weeks after the second dose of vaccine against the SARS-CoV-2 virus to determine his immunity.

Participant who performs his serological test when he receives the third dose of vaccine against the SARS-CoV-2 virus to determine his immunity.

Participant who performs a serological test between 12 and 14 weeks after the third dose of SARS-CoV-2 vaccine to determine immunity. And who has agreed to undergo serological testing prior to the third dose of the vaccine.

Participants accept to undergo 2 serological tests to determine their immunity to the SARS-CoV-2 virus.

Inclusion Criteria: To be an employee or independent collaborator at the GHdC Exclusion Criteria: Refusal to take a blood test for anti-SARS-CoV-2 antibodies Regarding amendment 1: Members who did not receive the third dose of PFIZER vaccine (Comirnaty) during the GHdC vaccination campaign and who did not performed a blood test to measure anti-SARS-CoV-2 antibodies.