COVID-19 reinfection in the presence of neutralizing antibodies

Abstract

After a short recovery period, COVID-19 reinfections could occur in convalescent patients, even those with measurable levels of neutralizing antibodies. Effective vaccinations and protective public health measures are recommended for the convalescent COVID-19 patients.

Keywords: COVID-19; SARS-CoV-2; neutralizing antibody; reinfection.

Figure 1.

Detailed timelines and high-resolution chest CT scans of reinfected cases. (a) Timeline of the six reinfected COVID-19 patients. Infection stages are highlighted in different colors on the first line for each case. RT-PCR results and duration of hospitalization are shown in the second lines for each patient. Durations of COVID-19 symptoms are shown in the third lines. Red line, primary infection; orange line, secondary infection; green line, infection interval between two infection episodes; light green line, convalescent phase of the secondary infection; red dot, positive RT-PCR tests; green dot, negative RT-PCR test; tan line, symptom duration; gray arrows, follow-up dates initialed by doctors or patients; white arrows, discharge dates from hospital. (b) Representative high-resolution CT images before and after the secondary infections. Increasing and multifocal ground-glass changes in subpleural areas were observed (P1: dorsal segment of right lower lobe; P2: right upper lobe, left lingual lobe and bilateral lower lobes). (c) Titer dynamics of antibodies against SARS-CoV-2 RBD, and neutralizing activity against live virus of reference SARS-CoV-2 and D614 variants in six patients. Green bars, anti-RBD IgG titers; sienna bars, anti-RBD IgM titers; line and dots, neutralizing ID50 against authentic virus of SARS-CoV-2 reference strain (purple) and D614G variant (orange). Background color shows the infection period, with the first and second infection periods shaded, and recovered periods in white.