Abstract
Background
Long-term studies of vaccine recipients are necessary to understand SARS-CoV-2 antibody durability, assess the impact of boosters on antibody levels, and protection from infection. The identification of vaccine breakthrough infections among fully vaccinated populations will be important in understanding vaccine efficacy and SARS-CoV-2 vaccine escape capacity.
Methods
SARS-CoV-2 Spike-RBD (S) and Nucleocapsid (N) IgG levels were measured in a longitudinal study of 1000 Chicago healthcare workers who were infection-naïve or previously-infected and then vaccinated. Changes in S and N IgG were followed up to 14 months and vaccine breakthrough infections were identified by increasing N IgG.
Results
SARS-CoV-2 S IgG antibody levels among previously infected and previously non-infected individuals decreased steadily for 11 months after vaccination. Administration of a booster 8-11 months post-vaccination increased S IgG levels more than 2-fold beyond those observed after 2 doses resulting in indistinguishable S IgG levels between previously-infected and uninfected individuals. Increases in N IgG identified vaccine breakthrough infections and showed over 15% breakthrough infection rates during the Omicron wave starting in December 2021.
Conclusions
These results demonstrate SARS-CoV-2 antibody changes after vaccination and breakthrough infections and identify high levels of vaccine breakthrough infections during the Omicron wave based on N IgG increases.
Keywords: SAR-CoV-2, Vaccine, Booster, Antibodies, Breakthrough infection
Vaccine breakthrough rates increased during SARS-CoV-2 Omicron waves and displayed higher Spike and Nucleocapsid IgG levels compared to breakthroughs from previous variants. SARS-CoV-2 Nucleocapsid IgG is a useful marker for identifying recent COVID-19 infection in vaccinated individuals.
Contributor Information
Mark Anderson, Abbott Laboratories, Abbott Diagnostics Division, Abbott Park, Illinois, United States; Abbott Pandemic Defense Coalition, Abbott Diagnostics Division, Abbott Park, Illinois, United States.
Michael Stec, Abbott Laboratories, Abbott Diagnostics Division, Abbott Park, Illinois, United States; Abbott Pandemic Defense Coalition, Abbott Diagnostics Division, Abbott Park, Illinois, United States.
Amy Gosha, Rush University Medical Center, Department of Internal Medicine, Chicago, Illinois, United States.
Taha Mohammad, Rush University Medical Center, Department of Internal Medicine, Chicago, Illinois, United States.
Michael Boler, Rush University Medical Center, Department of Internal Medicine, Chicago, Illinois, United States.
Rebeca Tojo Suarez, Rush University Medical Center, Department of Internal Medicine, Chicago, Illinois, United States.
Dylan Behun, Rush University Medical Center, Department of Internal Medicine, Chicago, Illinois, United States.
Alan Landay, Rush University Medical Center, Department of Internal Medicine, Chicago, Illinois, United States.
Gavin Cloherty, Abbott Laboratories, Abbott Diagnostics Division, Abbott Park, Illinois, United States; Abbott Pandemic Defense Coalition, Abbott Diagnostics Division, Abbott Park, Illinois, United States.
James Moy, Rush University Medical Center, Department of Internal Medicine, Chicago, Illinois, United States.
Supplementary Material
Associated Data
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