Ad5-nCoV booster and Omicron variant breakthrough infection following two doses of inactivated vaccine elicit comparable antibody levels against Omicron variants.

Little information is available for antibody levels against SARS-CoV-2 variants of concern induced by Omicron breakthrough infection and a third booster with an inactivated vaccine (InV) or Ad5-nCoV in people with completion of two InV doses. Plasma was collected from InV pre-vaccinated Omicron-infected patients (OIPs), unvaccinated OIPs between 0 and 22 days, and healthy donors (HDs) 14 days or 6 months after the second doses of an InV and 14 days after a homogenous booster or heterologous booster of Ad5-nCoV. Anti-Wuhan-, Anti-Delta-, and Anti-Omicron-receptor binding domain (RBD)-IgG titers were detected using enzyme-linked immunosorbent assay. InV pre-vaccinated OIPs had higher anti-Wuhan-, anti-Delta-, and anti-Omicron-RBD-IgG titers compared to unvaccinated OIPs. Anti-Wuhan-RBD-IgG titers sharply increased in InV pre-vaccinated OIPs 0-5 days postinfection (DPI), while the geometric mean titers (GMTs) of anti-Delta- and anti-Omicron-RBD-IgG were 3.3-fold and 12.0-fold lower. Then, the GMT of anti-Delta- and anti-Omicron-RBD-IgG increased to 35 112 and 28 186 during 11-22 DPI, about 2.6-fold and 3.2-fold lower, respectively, than the anti-Wuhan-RBD-IgG titer. The anti-Wuhan-, anti-Delta-, and anti-Omicron-RBD-IgG titers declined over time in HDs after two doses of an InV, with 25.2-fold, 5.6-fold, and 4.5-fold declination, respectively, at 6 months relative to the titers at 14 days after the second vaccination. Anti-Wuhan-, anti-Delta-, and anti-Omicron-RBD-IgG titers elicited by a heterologous Ad5-nCoV booster were significantly higher than those elicited by an InV booster, comparable to those in InV pre-vaccinated OIPs. InV and Ad5-nCoV boosters could improve humoral immunity against Omicron variants. Of these, the Ad5-nCoV booster is a better alternative.

Comparison of Clinical Features and CT Temporal Changes Between Familial Clusters and Non-familial Patients With COVID-19 Pneumonia.

Purpose: This study aimed to compare the clinical characteristics, laboratory findings, and chest computed tomography (CT) findings of familial cluster (FC) and non-familial (NF) patients with coronavirus disease 2019 (COVID-19) pneumonia. Methods: This retrospective study included 178 symptomatic adult patients with laboratory-confirmed COVID-19. The 178 patients were divided into FC (n = 108) and NF (n = 70) groups. Patients with at least two confirmed COVID-19 cases in their household were classified into the FC group. The clinical and laboratory features between the two groups were compared and so were the chest CT findings on-admission and end-hospitalization. Results: Compared with the NF group, the FC group had a longer period of exposure (13.1 vs. 8.9 days, p < 0.001), viral shedding (21.5 vs. 15.9 days, p < 0.001), and hospital stay (39.2 vs. 22.2 days, p < 0.001). The FC group showed a higher number of involved lung lobes on admission (3.0 vs. 2.3, p = 0.017) and at end-hospitalization (3.6 vs. 1.7, p < 0.001) as well as higher sum severity CT scores at end-hospitalization (4.6 vs. 2.7, p = 0.005) than did the NF group. Conversely, the FC group had a lower lymphocyte count level (p < 0.001) and a significantly lower difference in the number of involved lung lobes (Δnumber) between admission and discharge (p < 0.001). Notably, more cases of severe or critical illness were observed in the FC group than in the NF group (p = 0.036). Conclusions: Patients in the FC group had a worse clinical course and outcome than those in the NF group; thus, close monitoring during treatment and follow-ups after discharge would be beneficial for patients with familial infections.

Mean platelet volume/platelet count ratio predicts severe pneumonia of COVID-19.

BACKGROUND: Although platelet mean volume/platelet count ratio (MPR) is considered to be a crucial marker of inflammatory and infectious diseases, the relationship between MPR and novel coronavirus infectious disease 2019 (COVID-19) remains unclear. METHODS: In this retrospective study, 85 patients with confirmed COVID-19 were enrolled and divided into low and high MPR group. Data from repeated measures were compared by the generalized estimating equations. Cox regression analyses were performed to assess the impact of MPR on the incidence of severe pneumonia (SP), with inverse probability of treatment weighting (IPTW) used to reduce confounding bias. The primary outcome is the incidence of SP of COVID-19. RESULTS: During follow-up, 17 (20.0%) patients were developed to SP. Compared with mild patients, patients with SP developed showed a higher MPR level at baseline, day 1, day 2, and day 3 after admission (P = .005, P = .015, P = .009, and P = .032, respectively). Kaplan-Meier method showed a higher incidence of SP in the high MPR group than the low MPR group (log-rank test = 10.66, P = .001). After adjustment, high MPR was associated with an elevated incidence of SP (HR, 5.841, 95% CI, 1.566-21.791, P = .009). The IPTW method also suggested that MPR was a significant factor related to the incidence of SP (HR, 8.337, 95% CI, 4.045-17.182, P < .001). CONCLUSION: High MPR level is an independent risk factor for severe pneumonia in patients with COVID-19.

Treatment With Convalescent Plasma for Critically Ill Patients With Severe Acute Respiratory Syndrome Coronavirus 2 Infection.

As of March 24, 2020, novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been responsible for 379,661 infection cases with 16,428 deaths globally, and the number is still increasing rapidly. Herein, we present four critically ill patients with SARS-CoV-2 infection who received supportive care and convalescent plasma. Although all four patients (including a pregnant woman) recovered from SARS-CoV-2 infection eventually, randomized trials are needed to eliminate the effect of other treatments and investigate the safety and efficacy of convalescent plasma therapy.

Positive rectal swabs in young patients recovered from coronavirus disease 2019 (COVID-19).

OBJECTIVES: To investigate the widely concerned issue about positive real-time reverse transcription polymerase chain reaction (RT-PCR) test results after discharge in patients recovered from coronavirus disease 2019 (COVID-19). METHODS: We identified seven cases of COVID-19 who was readmitted to hospital because of positive RT-PCR after discharge, including three pediatrics and four young adult patients. RESULTS: Six patients had positive rectal swabs but negative throat swabs, and one patient had positive throat swabs. All the patients continued to be asymptomatic and had unchanged chest computed tomography from previous images. The time from hospital discharge to positive RT-PCR after recovery was 7-11 days. The time from positive to negative rectal swabs was 5-23 days. CONCLUSION: The study might suggest the positive RT-PCR after recovery did not mean disease relapse or virus reinfection. Adding RT-PCR test of rectal swabs to the criteria for discharge or discontinuation of quarantine might be necessary.