Anti-SARS-CoV-2 IgG in the Urine of Individuals Vaccinated Against COVID-19 With and Without Previous Infection

Urine is a non-invasive sample that has been proven useful in the detection of anti-SARS-CoV-2 antibodies in patients with COVID-19. To assess the potential of urine for serological surveys in a real-world scenario, we performed SARS-CoV-2 serology on urine samples from vaccinated individuals, with and without prior confirmed COVID-19. Methods: Using an in-house indirect ELISA, we measured IgG against recombinant Spike (S) and Nucleocapsid (N) proteins of SARS-CoV-2 in the urine and paired serum from 149 individuals vaccinated with AD26.COV2.S, an S protein-based COVID-19 vaccine. Results: Anti-S and anti-N IgG were higher in the urine and serum of participants with confirmed prior COVID-19 when compared to those without previous infection. Urinary anti-S effectively distinguished vaccinated individuals with (AUC=0.96) and without (AUC=0.88) prior infection from negative controls (non-vaccinated, non-previously infected individuals) (p<0.0001). Among vaccinated participants, urinary anti-S and anti-N identified previous infection with AUC of 0.73 (p<0.0001) and 0.60 (p=0.03), respectively. Conclusion: Our findings demonstrate that urinary anti-SARS-CoV-2 reflect vaccination and previous COVID-19. We highlight the potential of urine as a convenient sample in the initial clinical and epidemiological management of possible new epidemics.