Risultati per: Ipotesi sull’origine di Omicron e sua evoluzione

In Reply Our recent Research Letter showed that all-cause excess mortality in Massachusetts was higher during the Omicron wave than the Delta wave of COVID-19. One potential explanation was a higher “mortality product” during Omicron—a greater number of infections offset a possibly lower infection fatality rate, owing to higher vaccination and booster rates, immunity derived from infections, or both.

Objective
Two COVID-19 outbreaks occurred in Henan province in early 2022—one was a Delta variant outbreak and the other was an Omicron variant outbreak. COVID-19 vaccines used at the time of the outbreak were inactivated, 91.8%; protein subunit, 7.5%; and adenovirus5-vectored, 0.7% vaccines. The outbreaks provided an opportunity to evaluate variant-specific breakthrough infection rates and relative protective effectiveness of homologous inactivated COVID-19 vaccine booster doses against symptomatic infection and pneumonia.
Design
Retrospective cohort study

Methods
We evaluated relative vaccine effectiveness (rVE) with a retrospective cohort study of close contacts of infected individuals using a time-dependent Cox regression model. Demographic and epidemiologic data were obtained from the local Centers for Disease Control and Prevention; clinical and laboratory data were obtained from COVID-19-designated hospitals. Vaccination histories were obtained from the national COVID-19 vaccination dataset. All data were linked by national identification number.

Results
Among 784 SARS-CoV-2 infections, 379 (48.3%) were caused by Delta and 405 (51.7%) were caused by Omicron, with breakthrough rates of 9.9% and 17.8%, respectively. Breakthrough rates among boosted individuals were 8.1% and 4.9%. Compared with subjects who received primary vaccination series ≥180 days before infection, Cox regression modelling showed that homologous inactivated booster vaccination was statistically significantly associated with protection from symptomatic infection caused by Omicron (rVE 59%; 95% CI 13% to 80%) and pneumonia caused by Delta (rVE 62%; 95% CI 34% to 77%) and Omicron (rVE 87%; 95% CI 3% to 98%).

Conclusions
COVID-19 vaccination in China provided good protection against symptomatic COVID-19 and COVID-19 pneumonia caused by Delta and Omicron variants. Protection declined 6 months after primary series vaccination but was restored by homologous inactivated booster doses given 6 months after the primary series.

This cohort study assesses the capacity of passive immunization and tixagevimab and cilgavimab to inhibit interaction between receptor-binding domains and angiotensin-converting enzyme 2 in patients with hemato-oncologic diseases.

Circulation, Volume 146, Issue Suppl_1, Page A10255-A10255, November 8, 2022. Introduction:Coronavirus disease 2019 (COVID-19) with evidence of myocardial injury, defined as troponin elevation, has been demonstrated to be associated with worse outcomes. The temporal changes in outcomes in these patients during various phases of the pandemic remain unclear.Hypothesis:We sought to evaluate outcomes during the Omicron phase compared to previous phases of the pandemic.Methods:We analyzed COVID-19-positive patients with myocardial injury who presented to the MedStar Health system (11 hospitals in Washington, DC and Maryland) during Phase 1 of the pandemic (March 1 – June 30, 2020), Phase 2 (October 1, 2020 – January 31, 2021) and Phase 3 (Omicron) (December 1, 2021 – March 31, 2022) comparing their characteristics and outcomes. The primary end point was in-hospital mortality.Results:The cohort included 2079 COVID-19-positive admitted patients for whom troponin-I or high-sensitive troponin was elevated (Phase 1: n=150, Phase 2: n=854, Phase 3 [Omicron]: n=1075). Baseline characteristics were overall similar. Inflammatory markers were significantly elevated in Phase 1 as compared to Phase 2 and the Omicron Phase. The use of remdesivir and dexamethasone was most seen in Phase 2. In the Omicron Phase, 52.6% of patients were fully vaccinated. In-hospital mortality although high was lower in the Omicron Phase as compared to Phase 1 and Phase 2 (23.3% vs. 59.3% vs. 28.1%; p

New England Journal of Medicine, Ahead of Print.

Mutazioni su proteina Spike frutto dell’adattamento nei roditori

New England Journal of Medicine, Ahead of Print.

Annals of Internal Medicine, Volume 175, Issue 10, Page W119, October 2022.

Annals of Internal Medicine, Volume 175, Issue 10, Page W119, October 2022.

I ricercatori stanno monitorando le varianti che potranno essere responsabili di una nuova ondata di Sars-CoV2 nella stagione invernale

Annals of Internal Medicine, Volume 175, Issue 12, Page 1693-1706, December 2022.

Annals of Internal Medicine, Volume 175, Issue 12, Page 1685-1692, December 2022.

Annals of Internal Medicine, Ahead of Print.

Annals of Internal Medicine, Ahead of Print.

To the Editor We have some concerns about the recent Research Letter that investigated the risk of infection and hospitalization among vaccinated and unvaccinated children and adolescents after the emergence of the SARS-CoV-2 Omicron variant.