The rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has elicited an equally rapid response aiming to develop a COVID-19 vaccine. These efforts are encouraging; however, ...comprehensive efficacy and safety evaluations are essential in the development of a vaccine, and we can learn from previous vaccine development campaigns. In this Perspective, we summarize examples of vaccine-associated disease enhancement in the history of developing vaccines against respiratory syncytial virus, dengue virus, SARS-CoV and Middle East respiratory syndrome coronavirus, which highlight the importance of a robust safety and efficacy profile, and present recommendations for preclinical and clinical evaluation of COVID-19 vaccine candidates as well as for vaccine design and optimization.
Multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with higher transmission potential have been emerging globally, including SARS-CoV-2 variants from the United Kingdom ...and South Africa. We report 4 travelers from Brazil to Japan in January 2021 infected with a novel SARS-CoV-2 variant with an additional set of mutations.
AbstractObjectiveTo estimate population health outcomes with delayed second dose versus standard schedule of SARS-CoV-2 mRNA vaccination.DesignSimulation agent based modeling study.SettingSimulated ...population based on real world US county.ParticipantsThe simulation included 100 000 agents, with a representative distribution of demographics and occupations. Networks of contacts were established to simulate potentially infectious interactions though occupation, household, and random interactions.InterventionsSimulation of standard covid-19 vaccination versus delayed second dose vaccination prioritizing the first dose. The simulation runs were replicated 10 times. Sensitivity analyses included first dose vaccine efficacy of 50%, 60%, 70%, 80%, and 90% after day 12 post-vaccination; vaccination rate of 0.1%, 0.3%, and 1% of population per day; assuming the vaccine prevents only symptoms but not asymptomatic spread (that is, non-sterilizing vaccine); and an alternative vaccination strategy that implements delayed second dose for people under 65 years of age, but not until all those above this age have been vaccinated.Main outcome measuresCumulative covid-19 mortality, cumulative SARS-CoV-2 infections, and cumulative hospital admissions due to covid-19 over 180 days.ResultsOver all simulation replications, the median cumulative mortality per 100 000 for standard dosing versus delayed second dose was 226 v 179, 233 v 207, and 235 v 236 for 90%, 80%, and 70% first dose efficacy, respectively. The delayed second dose strategy was optimal for vaccine efficacies at or above 80% and vaccination rates at or below 0.3% of the population per day, under both sterilizing and non-sterilizing vaccine assumptions, resulting in absolute cumulative mortality reductions between 26 and 47 per 100 000. The delayed second dose strategy for people under 65 performed consistently well under all vaccination rates tested.ConclusionsA delayed second dose vaccination strategy, at least for people aged under 65, could result in reduced cumulative mortality under certain conditions.
Increased understanding of whether individuals who have recovered from COVID-19 are protected from future SARS-CoV-2 infection is an urgent requirement. We aimed to investigate whether antibodies ...against SARS-CoV-2 were associated with a decreased risk of symptomatic and asymptomatic reinfection.
A large, multicentre, prospective cohort study was done, with participants recruited from publicly funded hospitals in all regions of England. All health-care workers, support staff, and administrative staff working at hospitals who could remain engaged in follow-up for 12 months were eligible to join The SARS-CoV-2 Immunity and Reinfection Evaluation study. Participants were excluded if they had no PCR tests after enrolment, enrolled after Dec 31, 2020, or had insufficient PCR and antibody data for cohort assignment. Participants attended regular SARS-CoV-2 PCR and antibody testing (every 2–4 weeks) and completed questionnaires every 2 weeks on symptoms and exposures. At enrolment, participants were assigned to either the positive cohort (antibody positive, or previous positive PCR or antibody test) or negative cohort (antibody negative, no previous positive PCR or antibody test). The primary outcome was a reinfection in the positive cohort or a primary infection in the negative cohort, determined by PCR tests. Potential reinfections were clinically reviewed and classified according to case definitions (confirmed, probable, or possible) and symptom-status, depending on the hierarchy of evidence. Primary infections in the negative cohort were defined as a first positive PCR test and seroconversions were excluded when not associated with a positive PCR test. A proportional hazards frailty model using a Poisson distribution was used to estimate incidence rate ratios (IRR) to compare infection rates in the two cohorts.
From June 18, 2020, to Dec 31, 2020, 30 625 participants were enrolled into the study. 51 participants withdrew from the study, 4913 were excluded, and 25 661 participants (with linked data on antibody and PCR testing) were included in the analysis. Data were extracted from all sources on Feb 5, 2021, and include data up to and including Jan 11, 2021. 155 infections were detected in the baseline positive cohort of 8278 participants, collectively contributing 2 047 113 person-days of follow-up. This compares with 1704 new PCR positive infections in the negative cohort of 17 383 participants, contributing 2 971 436 person-days of follow-up. The incidence density was 7·6 reinfections per 100 000 person-days in the positive cohort, compared with 57·3 primary infections per 100 000 person-days in the negative cohort, between June, 2020, and January, 2021. The adjusted IRR was 0·159 for all reinfections (95% CI 0·13–0·19) compared with PCR-confirmed primary infections. The median interval between primary infection and reinfection was more than 200 days.
A previous history of SARS-CoV-2 infection was associated with an 84% lower risk of infection, with median protective effect observed 7 months following primary infection. This time period is the minimum probable effect because seroconversions were not included. This study shows that previous infection with SARS-CoV-2 induces effective immunity to future infections in most individuals.
Department of Health and Social Care of the UK Government, Public Health England, The National Institute for Health Research, with contributions from the Scottish, Welsh and Northern Irish governments.
"Fuga con Pajarillo" Rincón Suárez, Liz Johana
Papel político (Bogotá, Colombia : 1995),
11/2022, Letnik:
27
Journal Article
Este artículo tiene como objetivo comprender la experiencia y las trayectorias de migración de mujeres venezolanas asentadas de manera transitoria en la ciudad de Cali, Colombia. Parte de la ...pregunta: ¿cómo mujeres venezolanas en tránsito significan la experiencia migratoria y en qué medida dichos significados articulan procesos de agencia y de ejercicio de derechos? Los datos presentados son el resultado de un ejercicio etnográfico con treinta familias caminantes en el campamento de refugiados del terminal y caminantes en la Vía Panamericana en Cali, y de cinco entrevistas en profundidad realizadas a mujeres entre los 23 y 36 años. Los resultados se analizaron a la luz de los enfoques teórico-críticos de las migraciones que vinculan los conceptos de trayectoria, migración pendular y mundos de la vida cotidiana. La conclusión final del análisis considera que la migración en tránsito es una experiencia que expresa múltiples violencias para las mujeres, pero al mismo tiempo produce confrontaciones en los significados y prácticas culturales. Estas confrontaciones devienen en nuevas subjetividades que impactan los universos de sentido de la sociedad de origen y de acogida. Las trayectorias de las caminantes dan cuenta de la necesidad de comprender la migración de tránsito como migración de refugio, lo cual implica la construcción de una política migratoria que supere las miradas Estado-céntricas sobre la ciudadanía.
OBJECTIVES
The objective was to compare COVID‐19 outcomes in the Omicron‐driven fourth wave with prior waves in the Western Cape, assess the contribution of undiagnosed prior infection to differences ...in outcomes in a context of high seroprevalence due to prior infection and determine whether protection against severe disease conferred by prior infection and/or vaccination was maintained.
METHODS
In this cohort study, we included public sector patients aged ≥20 years with a laboratory‐confirmed COVID‐19 diagnosis between 14 November and 11 December 2021 (wave four) and equivalent prior wave periods. We compared the risk between waves of the following outcomes using Cox regression: death, severe hospitalisation or death and any hospitalisation or death (all ≤14 days after diagnosis) adjusted for age, sex, comorbidities, geography, vaccination and prior infection.
RESULTS
We included 5144 patients from wave four and 11,609 from prior waves. The risk of all outcomes was lower in wave four compared to the Delta‐driven wave three (adjusted hazard ratio (aHR) 95% confidence interval (CI) for death 0.27 0.19; 0.38. Risk reduction was lower when adjusting for vaccination and prior diagnosed infection (aHR: 0.41, 95% CI: 0.29; 0.59) and reduced further when accounting for unascertained prior infections (aHR: 0.72). Vaccine protection was maintained in wave four (aHR for outcome of death: 0.24; 95% CI: 0.10; 0.58).
CONCLUSIONS
In the Omicron‐driven wave, severe COVID‐19 outcomes were reduced mostly due to protection conferred by prior infection and/or vaccination, but intrinsically reduced virulence may account for a modest reduction in risk of severe hospitalisation or death compared to the Delta‐driven wave.
Long-term complications of COVID-19 Desai, Amar D; Lavelle, Michael; Boursiquot, Brian C ...
American Journal of Physiology: Cell Physiology,
01/2022, Letnik:
322, Številka:
1
Journal Article
Recenzirano
Odprti dostop
SARS-CoV-2 has rapidly spread across the globe and infected hundreds of millions of people worldwide. As our experience with this virus continues to grow, our understanding of both short-term and ...long-term complications of infection with SARS-CoV-2 continues to grow as well. Just as there is heterogeneity in the acute infectious phase, there is heterogeneity in the long-term complications seen following COVID-19 illness. The purpose of this review article is to present the current literature with regards to the epidemiology, pathophysiology, and proposed management algorithms for the various long-term sequelae that have been observed in each organ system following infection with SARS-CoV-2. We will also consider future directions, with regards to newer variants of the virus and their potential impact on the long-term complications observed.
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