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Case isolation and contact tracing can contribute to the control of COVID-19 outbreaks1,2. However, it remains unclear how real-world social networks could influence the effectiveness and efficiency of such approaches. To address this issue, we simulated control strategies for SARS-CoV-2 transmission in a real-world social network generated from high-resolution GPS data that were gathered in the course of a citizen-science experiment3,4. We found that tracing the contacts of contacts reduced the size of simulated outbreaks more than tracing of only contacts, but this strategy also resulted in almost half of the local population being quarantined at a single point in time. Testing and releasing non-infectious individuals from quarantine led to increases in outbreak size, suggesting that contact tracing and quarantine might be most effective as a 'local lockdown' strategy when contact rates are high. Finally, we estimated that combining physical distancing with contact tracing could enable epidemic control while reducing the number of quarantined individuals. Our findings suggest that targeted tracing and quarantine strategies would be most efficient when combined with other control measures such as physical distancing.

Since the emergence of coronavirus disease 2019 (COVID-19), unprecedented movement restrictions and social distancing measures have been implemented worldwide. The socioeconomic repercussions have fueled calls to lift these measures. In the absence of population-wide restrictions, isolation of infected individuals is key to curtailing transmission. However, the effectiveness of symptom-based isolation in preventing a resurgence depends on the extent of presymptomatic and asymptomatic transmission. We evaluate the contribution of presymptomatic and asymptomatic transmission based on recent individual-level data regarding infectiousness prior to symptom onset and the asymptomatic proportion among all infections. We found that the majority of incidences may be attributable to silent transmission from a combination of the presymptomatic stage and asymptomatic infections. Consequently, even if all symptomatic cases are isolated, a vast outbreak may nonetheless unfold. We further quantified the effect of isolating silent infections in addition to symptomatic cases, finding that over one-third of silent infections must be isolated to suppress a future outbreak below 1% of the population. Our results indicate that symptom-based isolation must be supplemented by rapid contact tracing and testing that identifies asymptomatic and presymptomatic cases, in order to safely lift current restrictions and minimize the risk of resurgence.

Beijing acted against the coronavirus with stunning force, as its official narratives recount. But not before a political logjam had allowed a local outbreak to kindle a global pandemic.

Scientists say that widespread testing is needed to get outbreaks of the new coronavirus under control. But in many regions, there's a shortage of the chemicals needed to run tests. In several countries, health officials have started using a strategy that was first proposed in the Second World War: group testing. By testing samples from many people at once, this method can save time, chemical reagents and money, say researchers.

Great powers rise and fall, shaping each transitional period of global power shift and its geographic concentration. Currently, the world is witnessing a profound transformation in the geopolitical arena of international affairs. For the past years, the pundits have been propagating the emergence of an Asian multipolar century, with a shift from the Atlantic to the Pacific realm. However, following the COVID-19 virus outbreak, this year marks the obvious manifestation of an Indo-Pacific decade, with the US, China, and potentially India being the main protagonists in an emerging competition. This time, it is the unfolding of regional centres of power, which create the delusive impression of multipolarity, while in fact a new systemic bipolarity between the US and China comes to light. In the post-COVID-19 global context, the virus has become a catalyst of multiple systemic changes, inducing ad hoc constellations of regional actors-shaped by their geopolitical and geoeconomic interests-in a changing global order with eroding multilateral structures.

In December, Antarctica lost its status as the last continent free of COVID-19 when 36 people at the Chilean Bernardo O'Higgins research station tested positive. The station's isolation from other bases and fewer researchers in the continent means the outbreak is now likely contained.

The coronavirus offers an opening to change the world for the better, not least by undoing decades of neoliberalization to give vital professions in health care and education the appreciation they deserve. Unfortunately, as detailed in Naomi Klein's 'The Shock Doctrine', crises also offer ample opportunity for the established order to realize ambitions which are inconceivable in normal times. The global political economy before the outbreak of corona was defined by the rise of a global billionaire class, tech platforms, and illiberal(izing) nationalist politics, having jointly propelled a novel wave of (geo) political-economic restructuring which I have called neo-illiberalism. What will be the effects of coronavirus on this new status quo?

So many of us, including me, have been focused on the failure of the federal response to Covid-19, watching President Trump's catastrophe-by-public-policy roll out day after day since late February. I've written a lot about it in these pages. In a misplaced triumphalism, some people in states that have managed to have a relatively quiet summer with low rates of Covid-19 cases have chastised those in states with renewed outbreaks as being foolish or unheeding of scientific advice, as governors still slow-walk the response to the disease and ordinary people shun masks and flock to social gatherings. We all like to think of ourselves as different, doing the right thing, doing our part.

In December 2019, the Coronavirus disease 2019 (COVID-19), caused by a novel coronavirus SARS-CoV-2, emerged in Wuhan, Hubei province, China1 and soon spread across the world. In this ongoing pandemic, public health concerns and the urgent need for effective therapeutic measures require a deep understanding of its epidemiology, transmissibility and pathogenesis. Here we analyzed the clinical, molecular and immunological data from 326 confirmed cases of COVID-19 in Shanghai. Genomic sequences of SARS-CoV-2 assembled from 112 quality samples together with sequences in the Global Initiative on Sharing All Influenza Data (GISAID) showed a stable evolution and suggested two major lineages with differential exposure history during the early phase of the outbreak in Wuhan. Nevertheless, they exhibited similar virulence and clinical outcomes. Lymphocytopenia, especially the reduced CD4+ and CD8+ T cell counts upon admission, was predictive of disease progression. High levels of IL-6 and IL-8 during treatment were observed in patients with severe or critical disease and correlated with decreased lymphocyte count. The determinants of disease severity seemed to stem mostly from host factors such as age, lymphocytopenia, and its associated cytokine storm, whereas viral genetic variation did not significantly affect the outcomes.

The emergence of three lethal coronaviruses in <20 years and the urgency of the COVID-19 pandemic have prompted efforts to develop new therapeutic strategies, including by repurposing existing agents. After performing a comparative analysis of the three pathogenic human coronaviruses severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1), SARS-CoV-2, and Middle East respiratory syndrome coronavirus (MERS-CoV), we identified shared biology and host-directed drug targets to prioritize therapeutics with potential for rapid deployment against current and future coronavirus outbreaks.