Performance of commercial SARS-CoV-2 wild-type and Omicron BA.1 antibody assays compared with pseudovirus neutralization tests.

BACKGROUND: Commercially available ELISA-based antibody tests are used to approximate vaccination success against SARS-CoV-2 in at-risk patients, but it is unclear whether they correlate with neutralization of the Omicron variant. METHODS: 269 serum samples of a cohort of 44 non-immunosuppressed participants and 65 MTX-treated rheumatic patients taken before and after COVID-19 booster vaccinations were measured using COVID-19 antibody testing systems with wild-type and Omicron BA.1 antigens developed by three different manufacturers (surrogate virus neutralization test cPass, and binding antibody tests QuantiVac and SeraSpot), as well as with a pseudovirus neutralization test (pVNT). The pVNT was considered the gold standard for determining the presence and level of anti-SARS-CoV-2 antibodies. RESULTS: All three wild-type ELISAs showed excellent test performance compared with wild-type neutralization in pVNT. However, out of 56 samples without Omicron BA.1 neutralization in pVNT, 71.4% showed positive results in at least one and 28.6% in all three wild-type ELISAs at the manufacturer-defined cut-offs. Omicron ELISAs showed either decreased specificity (57.1% and 55.4% for binding ELISAs) or sensitivity (51.2% in cPass) compared to Omicron neutralization in pVNT. The proportion of any false positive results among all samples decreased from 26.5% before to 3.2% after booster vaccination, however binding antibody test specificities remained below 70%. CONCLUSIONS: We found a poorer test performance of new Omicron antibody test systems compared to wild-type tests in detecting neutralizing antibodies against the corresponding SARS-CoV-2 variants. Decisions for booster vaccination or passive immunization of at-risk patients should not be based solely on antibody test results.

15-Month Attributes of Post-Covid Syndrome in Therapeutically Vaccinated Outpatients

Background: In the third year of the coronavirus disease 2019 (COVID-19) pandemic, long-term post-COVID syndrome (PCS) following severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infections poses the significant challenge for patients and health systems globally. Whilst COVID-19 vaccinations prior to SARS-CoV-2 infection reduce the risk of PCS, the role of therapeutic vaccination in PCS recovery remains controversial. We present a 15 months longitudinal, prospective observational cohort study to examine long-term clinical courses, PCS recovery with and without vaccination as well as humoral immune responses in initially unvaccinated PCS patients. Method(s): A total of 227 COVID-19 convalescents of our initial mild COVID-19 outpatient cohort (N=958) from which longitudinal data was available were included in this study. PCS was defined according to the WHO definition. 76.7% (174/227) of individuals received at least one vaccination between 10 and 15 months after first SARS-CoV-2 infection. Receptor binding domain (RBD)- specific SARS-CoV-2 immunoglobulin G (IgG) and distinct symptom phenotypes (P) were longitudinally assessed for 15 months. Using binomial regression models, odds ratios (OR) with 95% confidence interval (95%CI) of descriptive, longitudinal variables associated with long-term PCS were calculated. Result(s): 35.8% (82/227) and 31.3% (71/227) of patients had PCS at months 10 and 15 (figure 1A). SARS-CoV-2 IgG titers were equally distributed over time among age groups, sex, and PCS. PCS occurred in 30.5% (53/174) of vaccinated and 34.0% (18/53) of unvaccinated patients. Between 6 and 10 months (DELTAT2/T3: not yet vaccinated) and 10 and 15 months (DELTAT3/T4: vaccinated) after symptom onset (figure 1B), a comparable fraction of PCS patients recovered (DELTAT2/T3: 22.5% and DELTAT3/T4: 20.0%). Fatigue/dyspnea (P2) and not anosmia/ageusia (P1) constituted PCS at month 15 (P2 23.9% versus P1 1.4%). Headache (P4) and diarrhea (P5) at baseline were risk factors for PCS at months 15, respectively (P4: OR 2.01 (95%CI 1.11-3.52), p= .018;P5: OR 3.01(95%CI 1.44-5.94), p= .002). Conclusion(s): Our results indicate, that distinct symptom phenotypes can constitute and predict long-term PCS 15 months after mild COVID. Recovery of PCS was observed similarly in both therapeutically vaccinated and unvaccinated patients. Thus, development of targeted PCS therapeutics is needed to improve patient care and future epidemiological investigations. (Figure Presented).

Stochasticity of infectious outbreaks and consequences for optimal interventions

Global strategies to contain a pandemic, such as social distancing and protective measures, are designed to reduce the overall transmission rate between individuals. Despite such measures, essential institutions, including hospitals, schools, and food producing plants, remain focal points of local outbreaks. Here we develop a model for the stochastic infection dynamics that predicts the statistics of local outbreaks from observables of the underlying global epidemics. Specifically, we predict two key outbreak characteristics: the probability of proliferation from a first infection in the local community, and the establishment size, which is the threshold size of local infection clusters where proliferation becomes likely. We derive these results using a contact network model of communities, and we show how the proliferation probability depends on the contact degree of the first infected individual. Based on this model, we suggest surveillance protocols by which individuals are tested proportionally to their degree in the contact network. We characterize the efficacy of contact-based protocols as a function of the epidemiological and the contact network parameters, and we show numerically that such protocols outperform random testing.

Direct Comparison of SARS-CoV-2 Infections after Vaccination with mRNA Vaccines

Die mRNA-basierten Impfstoffe BNT162b2 (BioNTech/Pfizer) und mRNA-1273 (Moderna) reduzierten in den Zulassungstudien das Risiko fur eine Coronavirus-Erkrankung 2019 (COVID-19) um mehr als 90%. Direkte Vergleichsstudien gab es dazu bislang nicht. Jetzt werteten Barbra A. Dickerman von der Harvard T.H. Chan School of Public Health in Boston und Kollegen Daten zur Wirksamkeit beider Impfstoffe bei Veteranen der US-Army aus.

Outcome of Pregnancies with intensive care SARS-CoV-2 Infection

Berichte zu Infektionen mit SARS-CoV-2 in der Schwangerschaft sind widerspruchlich. Jetzt wurden im Rahmen eines deutschen Registers mutterliche Charakteristika und klinische Prasentation von SARS-CoV-2-positiven Frauen analysiert, die wegen COVID-19 in der Schwangerschaft oder post partum intensivmedizinisch behandelt werden mussten.