Durability of neutralization against Omicron subvariants after vaccination and breakthrough infection.

Booster immunizations and breakthrough infections can elicit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron subvariant neutralizing activity. However, the durability of the neutralization response is unknown. We characterize the sensitivity of BA.1, BA.2, BA.2.75, BA.4/BA.5, BF.7, BQ.1.1, and XBB against neutralizing antibodies from vaccination, hybrid immunity, and breakthrough infections 4-6 months after vaccination and infection. We show that a two-dose CoronaVac or a third-dose ZF2001 booster elicits limited neutralization against Omicron subvariants 6 months after vaccination. Hybrid immunity as well as Delta, BA.1, and BA.2 breakthrough infections induce long-term persistence of the antibody response, and over 70% of sera neutralize BA.1, BA.2, BA.4/BA.5, and BF.7. However, BQ.1.1 and XBB, followed by BA.2.75, are more resistant to neutralization, with neutralizing titer reductions of ∼9- to 41-fold, ∼16- to 63-fold, and ∼4- to 25-fold, respectively. These data highlight additional vaccination in CoronaVac- or ZF2001-vaccinated individuals and provide insight into the durability of neutralization against Omicron subvariants.

Durability of neutralization against Omicron subvariants after vaccination and breakthrough infection

Booster immunizations and breakthrough infections can elicit SARS-CoV-2 Omicron subvariants neutralizing activity. However, the durability of the neutralization response is unknown. We characterize the sensitivity of BA.1, BA.2, BA.2.75, BA.4/BA.5, BF.7, BQ.1.1, and XBB against neutralizing antibodies from vaccination, hybrid immunity, and breakthrough infections 4–6 months after vaccination and infection. We show that a two-dose CoronaVac or a third-dose ZF2001 booster elicits limited neutralization against Omicron subvariants 6 months after vaccination. Hybrid immunity as well as Delta, BA.1, and BA.2 breakthrough infections induce long-term persistence of the antibody response, and over 70% of sera neutralize BA.1, BA.2, BA.4/BA.5, and BF.7. However, BQ.1.1 and XBB, followed by BA.2.75, are more resistant to neutralization, with neutralizing titer reductions of ∼9- to 41-fold, ∼16- to 63-fold, and ∼4- to 25-fold, respectively. These data highlight additional vaccination in CoronaVac- or ZF2001-vaccinated individuals and provide insight into the durability of neutralization against Omicron subvariants. Graphical Zhu et al. report that a two-dose CoronaVac or ZF2001 booster elicits limited neutralization against Omicron subvariants 6 months after vaccination. Hybrid immunity and Delta, BA.1 and BA.2 breakthrough infection induce neutralization against earlier Omicron variants, but not for BQ.1.1 and XBB, up to 5 months after vaccination or infection.

A Limited Spreading Event of COVID-19 Caused by Delta Variant in a Cosmetic Hospital - Yantai City, Shandong Province, China, 2021.

What is already known about this topic?: Coronavirus disease 2019 (COVID-19) outbreaks in the past were mostly caused by overseas transmission, but if control measures are not appropriately applied, domestic transmission could also cause large-scale local epidemics. What is added by this report?: This report covers all information of epidemic investigation processes, epidemiological characteristics and exposure history, transmission chains, sequencing results as well as public health measures taken for the COVID-19 cluster epidemic caused by the Delta variant in a cosmetic hospital in Yantai City in August 2021. What are the implications for public health practice?: The information provided in this report, including active case finding, community management, and mass testing, may assist public health professionals in dealing with local COVID-19 epidemics caused by domestic transmission.

Comparison of clinical characteristics between patients with coronavirus disease 2019 (COVID-19) who retested RT-PCR positive versus negative: a retrospective study of data from Nanjing.

BACKGROUND: The epidemiological and clinical characteristics of patients with coronavirus disease 2019 (COVID-19) have been reported. However, the prevalence of retesting positive by RT-PCR for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and the associated patient characteristics, remain unclear. METHODS: We included 90 confirmed cases of COVID-19 treated in the Nanjing Public Health Center from January 20, 2020 to February 16, 2020 in this retrospective study. All patients completed treatment for COVID-19 and were retested by RT-PCR for SARS-CoV-2 4-20 days after completion of therapy. The clinical characteristics between patients with who retested positive versus negative by RT-PCR were compared, and the factors predictive of positive retesting were analyzed. Positive retesting was modeled with the area under the receiver operating characteristic curve (AUC). RESULTS: The age range of the study population was 0.8-97 years, and all patients were cured or showed improvement. A total of 10 (11%) patients retested positive by RT-PCR 4-20 days after completion of therapy. As compared with patients who retested negative, those who retested positive had a lower percentage of pre-admission fever, a higher percentage of post-admission fever, a lower percentage of bilateral lung infection, higher white blood cell (WBC) count and creatine phosphokinase, and lower hypersensitive c-reactive protein (hs-CRP), interleukin-6 and erythrocyte sedimentation rates (all P<0.05). Logistic regression analysis of the above eight key variables showed that lower hs-CRP and higher WBC were independently associated with positive retesting by RT-PCR. A combination of hs-CRP and WBC were predictive of positive retesting, with an AUC of 0.859. CONCLUSIONS: Patients with COVID-19 who retested positive by RT-PCR for SARS-CoV-2 had mild symptoms and better blood testing results. A combination of hs-CRP and WBC may predict positive retesting by RT-PCR; however, the sensitivity and specificity should be studied further.

Clinical Use of Short-Course and Low-Dose Corticosteroids in Patients With Non-severe COVID-19 During Pneumonia Progression.

Background: The emerging coronavirus disease 2019 (COVID-19) has become a serious public health concern with a high number of fatalities. It is unclear whether corticosteroids could be a candidate for an early intervention strategy for patients with COVID-19. Methods: In this retrospective cohort study, we analyzed data from 28 corticosteroid-treated patients with non-severe but advanced COVID-19, in which short-course and low-dose corticosteroids were administered because of unremitting or worsening clinical conditions during hospitalization. To compare the effect of corticosteroids on viral clearance, 44 corticosteroid-untreated patients were included as controls. Results: At the time of admission, corticosteroid-treated patients (n = 28) had a more advanced baseline illness compared with corticosteroid-untreated patients (n = 44), as reflected by poorer blood laboratory parameters (lymphocytes, C-reactive protein, and lactate dehydrogenase) and more extensive chest computed tomography (CT) abnormalities. Corticosteroids were given because of radiological evidence of pneumonia progression (26/28) and/or unremitting fever (22/28) after admission. The median time from illness onset to corticosteroid treatment was 9 days (IQR, 7-10). The median duration and accumulated dose of corticosteroid treatment were 4.5 days [interquartile range (IQR), 3-5] and 140 mg of methylprednisolone (IQR, 120-200). Intravenous immunoglobulin (20 g per day for 3-5 days) was co-administered with corticosteroids. With the corticosteroid treatment, all patients achieved an abatement of fever within 1 day, and 78.6% (22/28) of the patients achieved radiological remission when evaluated about 3 days later. Only one (3.6%) patient progressed to severe COVID-19, and all patients recovered and were discharged without any sequela. The median time from illness onset to viral clearance was similar, as compared with 44 corticosteroid-untreated patients with relatively milder disease [18 (IQR 14.3-23.5) days vs. 17 (IQR, 12-20) days, p = 0.252]. When adjusted for age, sex, underlying comorbidities, baseline blood laboratory parameters, viral load, and chest radiological findings, the causal hazard ratio of corticosteroid treatment for the viral clearance was 0.79 (95%CI, 0.48-1.30, p = 0.34). Conclusion: Short-course and low-dose applications of corticosteroids, when co-administered with intravenous immunoglobulin, in non-severe COVID-19 patients during the stage of clinical deterioration may possibly prevent disease progression, while having a negligible impact on the viral clearance.

Transmission Potential of Asymptomatic and Paucisymptomatic Severe Acute Respiratory Syndrome Coronavirus 2 Infections: A 3-Family Cluster Study in China.

Data concerning the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in asymptomatic and paucisymptomatic patients are lacking. We report a 3-family cluster of infections involving asymptomatic and paucisymptomatic transmission. Eight of 15 (53%) members from 3 families were confirmed with SARS-CoV-2 infection. Of 8 patients, 3 were asymptomatic and 1 was paucisymptomatic. An asymptomatic mother transmitted the virus to her son, and a paucisymptomatic father transmitted the virus to his 3-month-old daughter. SARS-CoV-2 was detected in the environment of 1 household. The complete genomes of SARS-CoV-2 from the patients were > 99.9% identical and were clustered with other SARS-CoV-2 sequences reported from China and other countries.