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A double-blind randomized trial in South Africa documented poor efficacy of two doses of the ChAdOx1 nCoV-19 vaccine against the B.1.351 variant of SARS-CoV-2 that emerged in South Africa. Infections occurred in 3.2% of placebo recipients and in 2.5% of vaccine recipients. Thirty-nine of the 42 virus isolates were the B.1.351 variant. None of the cases led to hospitalization or death.

\"The COVID-19 pandemic isn't over. But even as governments around the world try to get it under control, they're also starting to talk about what happens next. How can we prevent another pandemic from killing millions of people and devastating the global economy? Can we even hope to accomplish this? Bill Gates believes the answer is yes, and he has written a largely upbeat book that lays out clearly and convincingly what the world should learn from COVID-19, explains the science of fighting pandemics, and suggests what all of us can do to help prevent another one. Given the worldwide success of How to Avoid a Climate Disaster (which debuted at #1 on the New York Times best seller list), Gates is more respected than ever for his approach to solving the world's biggest challenges\"-- Provided by publisher.

The global supply of COVID-19 vaccines remains limited. An understanding of the immune response that is predictive of protection could facilitate rapid licensure of new vaccines. Data from a randomized efficacy trial of the ChAdOx1 nCoV-19 (AZD1222) vaccine in the United Kingdom was analyzed to determine the antibody levels associated with protection against SARS-CoV-2. Binding and neutralizing antibodies at 28 days after the second dose were measured in infected and noninfected vaccine recipients. Higher levels of all immune markers were correlated with a reduced risk of symptomatic infection. A vaccine efficacy of 80% against symptomatic infection with majority Alpha (B.1.1.7) variant of SARS-CoV-2 was achieved with 264 (95% CI: 108, 806) binding antibody units (BAU)/ml: and 506 (95% CI: 135, not computed (beyond data range) (NC)) BAU/ml for anti-spike and anti-RBD antibodies, and 26 (95% CI: NC, NC) international unit (IU)/ml and 247 (95% CI: 101, NC) normalized neutralization titers (NF 50 ) for pseudovirus and live-virus neutralization, respectively. Immune markers were not correlated with asymptomatic infections at the 5% significance level. These data can be used to bridge to new populations using validated assays, and allow extrapolation of efficacy estimates to new COVID-19 vaccines. Defined levels of SARS-CoV-2-specific binding and neutralizing antibodies elicited by the COVID-19 vaccine ChAdOx1 nCoV-19 are identified as correlates of protection against symptomatic infection.

In a gripping, accessible narrative, a veteran science journalist lays out the shocking story of how the COVID-19 coronavirus pandemic happened and how to make sure this never happens again.

The Ad5-nCoV vaccine is a single-dose adenovirus type 5 (Ad5) vectored vaccine expressing the SARS-CoV-2 spike protein that was well-tolerated and immunogenic in phase 1 and 2 studies. In this study, we report results on the final efficacy and interim safety analyses of the phase 3 trial. This double-blind, randomised, international, placebo-controlled, endpoint-case driven, phase 3, clinical trial enrolled adults aged 18 years older at study centres in Argentina, Chile, Mexico, Pakistan, and Russia. Participants were eligible for the study if they had no unstable or severe underlying medical or psychiatric conditions; had no history of a laboratory-confirmed SARS-CoV-2 infection; were not pregnant or breastfeeding; and had no previous receipt of an adenovirus-vectored, coronavirus, or SARS-CoV-2 vaccine. After informed consent was obtained, 25 mL of whole blood was withdrawn from all eligible participants who were randomised in a 1:1 ratio to receive a single intramuscular dose of 0·5 mL placebo or a 0·5 mL dose of 5 × 1010 viral particle (vp)/mL Ad5-nCoV vaccine; study staff and participants were blinded to treatment allocation. All participants were contacted weekly by email, telephone, or text message to self-report any symptoms of COVID-19 illness, and laboratory testing for SARS-CoV-2 was done for all participants with any symptoms. The primary efficacy objective evaluated Ad5-nCoV in preventing symptomatic, PCR-confirmed COVID-19 infection occurring at least 28 days after vaccination in all participants who were at least 28 days postvaccination on Jan 15, 2021. The primary safety objective evaluated the incidence of any serious adverse events or medically attended adverse events postvaccination in all participants who received a study injection. This trial is closed for enrolment and is registered with ClinicalTrials.gov (NCT04526990). Study enrolment began on Sept 22, 2020, in Pakistan, Nov 6, 2020, in Mexico, Dec 2, 2020, in Russia and Chile, and Dec 17, 2020, in Argentina; 150 endpoint cases were reached on Jan 15, 2021, triggering the final primary efficacy analysis. One dose of Ad5-nCoV showed a 57·5% (95% CI 39·7–70·0, p=0·0026) efficacy against symptomatic, PCR-confirmed, COVID-19 infection at 28 days or more postvaccination (21 250 participants; 45 days median duration of follow-up [IQR 36–58]). In the primary safety analysis undertaken at the time of the efficacy analysis (36 717 participants), there was no significant difference in the incidence of serious adverse events (14 [0·1%] of 18 363 Ad5-nCoV recipients and 10 [0·1%] of 18 354 placebo recipients, p=0·54) or medically attended adverse events (442 [2·4%] of 18 363 Ad5-nCoV recipients and 411 [2·2%] of 18 354 placebo recipients, p=0·30) between the Ad5-nCoV or placebo groups, or any serious adverse events considered related to the study product (none in both Ad5-nCoV and placebo recipients). In the extended safety cohort, 1004 (63·5%) of 1582 of Ad5-nCoV recipients and 729 (46·4%) of 1572 placebo recipients reported a solicited systemic adverse event (p<0·0001), of which headache was the most common (699 [44%] of Ad5-nCoV recipients and 481 [30·6%] of placebo recipients; p<0·0001). 971 (61·3%) of 1584 Ad5-nCoV recipients and 314 (20·0%) of 1573 placebo recipients reported an injection-site adverse event (p<0·0001), of which pain at the injection site was the most frequent; reported by 939 (59%) Ad5-nCoV recipients and 303 (19%) placebo recipients. One dose of Ad5-nCoV is efficacious and safe in healthy adults aged 18 years and older. CanSino Biologics and the Beijing Institute of Biotechnology.

The global response to the Covid-19 pandemic is the greatest science policy failure in a generation. We knew this was coming. Warnings about the threat of a new pandemic have been made repeatedly since the 1980s and it was clear in January that a dangerous new virus was causing a devastating human tragedy in China. And yet the world ignored the warnings. Why? In this short and hard-hitting book, Richard Horton, editor of the medical journal The Lancet, scrutinizes the actions that governments around the world took - and failed to take - as the virus spread from its origins in Wuhan to the global pandemic that it is today. He shows that many Western governments and their scientific advisors made assumptions about the virus and its lethality that turned out to be mistaken. Valuable time was lost while the virus spread unchecked, leaving health systems unprepared for the avalanche of infections that followed. Drawing on his own scientific and medical expertise, Horton outlines the measures that need to be put in place, at both national and international levels, to prevent this kind of catastrophe from happening again. We're supposed to be living in an era where human beings have become the dominant influence on the environment, but Covid-19 has revealed the fragility of our societies and the speed with which our systems can come crashing down. We need to learn the lessons of this pandemic and we need to learn them fast because the next pandemic may arrive sooner than we think.

Ad26.COV2.S vaccine is a replication-incompetent human adenovirus type 26 vector containing the gene sequence that produces SARS-CoV-2 spike protein in a prefusion-stabilized conformation. In a randomized trial involving nearly 40,000 persons, vaccine efficacy was 66% against moderate to severe–critical Covid-19 and 85% against severe–critical Covid-19. Efficacy against the variant first identified in South Africa was 64% against moderate disease and 82% against severe–critical disease.

Presents strategies for dealing with the coronavirus pandemic, discussing how to practice social distancing and protect others, recognize the symptoms of the disease, and what to do in case of infection.

Two injections of mRNA-1273, a lipid nanoparticle–encapsulated mRNA-based vaccine produced in collaboration with the NIAID that encodes the SARS-CoV-2 spike protein, conferred protection against Covid-19 illness in 94% of vaccinated patients. Adverse effects of the vaccine were mild, transient local reactions, and the incidence of systemic effects such as fever, headache, and fatigue was low.