Quantification of Binding and Neutralizing Antibody Levels in COVID-19 Vaccinated Health Care Workers Over 1 Year

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic presents a great challenge to global health. The first case was identified in December 2019 in Wuhan, China and since has infected nearly 100 million people and claimed almost 2 million lives worldwide. In response, the medical community and scientists have worked hard to develop effective therapies and guidelines to treat a wide range of symptoms including the use of the antiviral drug remdesivir, convalescent plasma, antibiotics, steroids, and anticoagulant therapy. To prevent the spread of the disease, multiple vaccines based on mRNA and DNA technologies that include inactivated viral components have been developed and millions of doses are currently being administered worldwide. Early analysis of data from the phase III Pfizer/BioNTech and Moderna vaccine trials suggested the vaccine was more than 90% effective in preventing the illness with a good safety profile (Polack et al., 2020). However, there are still many unknowns regarding the long-term safety of these newer vaccine technologies and the level and duration of immunogenicity. SARS-CoV-2 infection results in seroconversion and production of anti-SARS-CoV-2 antibodies. The antibodies may suppress viral replication through neutralization but might also participate in COVID-19 pathogenesis through a process termed antibody-dependent enhancement (Lu et al., 2020). Rapid progress has been made in the research of antibody response and therapy in COVID-19 patients, including characterization of the clinical features of antibody responses in different populations infected by SARS-CoV-2, treatment of COVID-19 patients with convalescent plasma and intravenous immunoglobin products, isolation and characterization of a large panel of monoclonal neutralizing antibodies and early clinical testing, as well as clinical results from several COVID-19 vaccine candidates. In this study, we plan to assess the effic of both vaccines on the healthcare