*Article* **Relative COVID-19 Viral Persistence and Antibody Kinetics**

**Chung-Guei Huang 1,2,3,†, Avijit Dutta 3,4,†, Ching-Tai Huang 4,5, Pi-Yueh Chang 1,2, Mei-Jen Hsiao 1,2, Yu-Chia Hsieh 6,7, Shu-Min Lin 8,9, Shin-Ru Shih 1,2,3, Kuo-Chien Tsao 1,2 and Cheng-Ta Yang 8,9,\***


**Abstract:** A total of 15 RT-PCR confirmed COVID-19 patients were admitted to our hospital during the in-itial outbreak in Taiwan. The average time of virus clearance was delayed in seven patients, 24.14 ± 4.33 days compared to 10.25 ± 0.56 days post-symptom onset (PSO) in the other eight pa-tients. There was strong antibody response in patients with viral persistence at the pharynx, with peak values of serum antibody 677.2 ± 217.8 vs. 76.70 ± 32.11 in patients with delayed versus rapid virus clearance. The patients with delayed viral clearance had excessive antibodies of compromised quality in an early stage with the delay in peak virus neutralization efficacy, 34.14 ± 7.15 versus 12.50 ± 2.35 days PSO in patients with rapid virus clearance. Weak antibody re-sponse of patients with rapid viral clearance was also effective, with substantial and comparable neutralization efficacy, 35.70 ± 8.78 versus 41.37 ± 11.49 of patients with delayed virus clearance. Human Cytokine 48-Plex Screening of the serial sera samples revealed elevated concentrations of proinflammatory cytokines and chemokines in a deceased patient with delayed virus clear-ance and severe disease. The levels were comparatively less in the other two patients who suf-fered from severe disease but eventually survived.

**Keywords:** COVID-19; viral persistence; serum antibody; neutralization efficacy; cytokine profile
