Longitudinal kinetics of RBD+ antibodies in COVID-19 recovered patients over 14 months.

We describe the longitudinal kinetics of the serological response in COVID-19 recovered patients over a period of 14 months. The antibody kinetics in a cohort of 192 recovered patients, including 66 patients for whom follow-up serum samples were obtained at two to four clinic visits, revealed that RBD-specific antibodies decayed over the 14 months following the onset of symptoms. The decay rate was associated with the robustness of the response in that antibody levels that were initially highly elevated after the onset of symptoms subsequently decayed more rapidly. An exploration of the differences in the longitudinal kinetics between recovered patients and naïve vaccinees who had received two doses of the BNT162b2 vaccine showed a significantly faster decay in the naïve vaccinees, indicating that serological memory following natural infection is more robust than that following to vaccination. Our data highlighting the differences between serological memory induced by natural infection vs. vaccination contributed to the decision-making process in Israel regarding the necessity for a third vaccination dose.

A Time Frame for Testing Negative for SARS-COV2 in People with Obesity.

OBJECTIVE: Obesity is a major risk factor for becoming seriously ill with the 2019 novel coronavirus (COVID-19). One difficulty faced by clinicians and by patients is the unknown time frame of hospitalization until discharge of symptomatic patients. METHODS: We followed 34 patients with laboratory-confirmed COVID-19 infection who recovered fromthe infection. All diagnoses were given using semi-quantitative RT-PCR on nasopharyngeal swabs. Envelope protein gene (E), RNA-dependent RNA polymerase gene (RdRP), and nucleocapsid gene (N) were measured by RT-PCR. Weight was measured and height was self-reported. RESULTS: Mean ± SD age was 51.8 ± 16.7 years. Mean ± SD body mass index (BMI) was 27.4 ± 4.7 kg/m2. 26% (9/34) had obesity, with BMI above 30 kg/m2. Fifteen patients had BMI between 25 and 29.9 kg/m2. The mean length of hospital stay was longer for those with a BMI >25 kg/m2 (n = 24) than for those with a normal BMI (19.2 vs. 16.0 days, p = 0.08). Comparing people with obesity (BMI >30 kg/m2 or above) to those without obesity, the difference was larger (20.6 vs. 16.0 days, p = 0.06). A trend for correlation between body weight and the time to negative detection of RdRp gene was found (r = 0.33, p = 0.09). CONCLUSIONS: Our results highlight the need for priority of early detection and testing, and early therapy for people with obesity and COVID-19 infections.