Nature In-depth Report: What is the reason why the global new crown mortality rate is declining?

Intensive care specialist Bharath Kumar Tirupakuzhi Vijayaraghavan, who works at Apollo Main Hospital in India, died in April in their new crown ward, with about 70 per cent of cases on ventilators;
, an intensive care physician at the University of Pittsburgh, saw the same trend at the hospital where he worked.
more than 20,000 cases collected by the NHS between March and June also showed an increased chance of survival for critically ill patients.
, however, the experts point out that "god medicine" did not appear, and that there was no major breakthrough in the medical program, so what made COVID-19 seem less deadly? Recently, the journal Nature published a long report on this in detail.
hard-won treatment experience Experts point out that the changing perception of COVID-19 is important for improving treatment.
outbreak began, the new coronavirus was seen as a terrible new thing, with unproven interventions to save patients.
"The initial discussion about whether COVID-19 is a completely different new disease is so messy that things become extremely complicated, creating distractions that could derail anyone."
," says Dr Vijayaraghavan.
Charlotte Summers, an intensive care specialist at the University of Cambridge, gives an example of the detours that have been made.
she uses furore to describe the previous use of hydroxychloroquine in new crown therapy.
when some preliminary studies suggest that the drug for malaria appears to help treat the new crown, it has been strongly promoted by some, despite the lack of strong evidence.
, a large-scale study exploring a variety of new coronary therapies, published in June in the UK's RECOVERY clinical trial, showed that hydroxychloroquine did not improve the mortality rate in COVID-19 hospitalizations.
the trial stopped patients in the hydroxychloroquine group on June 5 after an interim analysis determined the lack of efficacy.
same time, the study and other studies have found that hydroxychloroquine can cause heart damage in some new crown patients, especially when used in combination with the antibiotic azithromycin.
dr Summers, hundreds of hydroxychloroquine clinical trials that have been launched waste the resources and effort that could have been spent elsewhere.
" for inpatients, hydroxychloroquine has been abandoned, so we have one less thing to worry about.
," she said.
time-tested drugs and programmes in the early stages of the outbreak, the "cytokine storm" is also a deepening concern.
this phenomenon is that some patients produce a large number of cytokines in the body, triggering an excessive inflammatory response.
so some doctors try to suppress the immune response using targeted therapies, such as inhibiting the activity of cytokine IL-6.
but subsequent studies have shown that some patients with severe COVID-19 do have elevated levels of IL-6, but not higher than other acute respiratory distress syndromes.
In turn, Dr Angus is not optimistic about the role of cytokine inhibitors: "For decades, researchers have been looking for targeted ways to suppress immune responses in critically ill patients, but we have been failing for two or three decades to improve outcomes by blocking cytokine cascading reactions.
" clinical trials seem to validate his claim.
phase 2/3 clinical trial in U.S. inpatients, IL-6 blocking antibody sarilumab failed to make significant improvements in severely ill patients.
"In just six months, I think we've repeated the results of the last 20 years in terms of acute respiratory distress syndrome."
," concluded Dr Marcus Schultz, an intensive care specialist at the University of Amsterdam Medical Center in the Netherlands.
more targeted drugs, steroids that suppress the immune system across the body have shown the benefits of reducing mortality in large trials.
is a commonly used corticosteroid that has been used to improve acute respiratory distress syndrome for decades.
in the early stages of the new crown outbreak, there was no certain decision as to whether corticosteroids would be used in critically ill COVID-19 patients.
now, there is a better clinical understanding of how to use dexamisson.
the results of the RECOVERY clinical trial, published in the New England Journal of Medicine (NEJM) in July, used dexamison for patients receiving mechanically breathable or oxygen-absorbing COVID-19 to reduce mortality within 28 days of treatment.
this result was further supported by the World Health Organization's (WHO) Rapid Evidence Assessment Panel for COVID-19 Therapy, which showed a 34 per cent reduction in the risk of total death after 28 days in a randomised group of severe COVID-19 patients treated with corticosteroids compared to the control group.
based on this evidence, the WHO panel recommended the use of systemic (oral or intravenous) corticosteroid therapy in patients with severe and critical COVID-19.
, no other drug has been shown to have a significant impact on improving COVID-19 mortality, including the first FDA-approved COVID-19 therapy, Redsyvir.
best solution is still unknown and hundreds of therapies are being tested, but due to the scale of the trial and other reasons, it is not possible to produce sufficiently credible results quickly.
the most in-depth studies of new coronary and antibodies, including purified antibodies, and plasma therapy (using antibody-rich plasma obtained from patients recovering from the disease).
, however, a randomized controlled trial conducted in more than 450 patients with mid-stage COVID-19 in 39 hospitals across India showed that the use of recovery plasma did not affect the risk of developing severe illness or death.
the UK's RECOVERY trial is collecting the highest levels of antibodies in recovery plasma for trials, expecting larger, more rigorous selection of rehab plasma trials to provide further answers.
purified antibodies are also under way.
Regn-COV2, a cocktail therapy at Regenerative Meta, has shown in preliminary clinical trials that it can help patients with mild COVID-19 relieve symptoms more quickly, but there is no evidence of whether it will reduce mortality in severe patients.
for different therapies, some multi-center clinical trials are testing different combinations of therapies to increase or decrease some therapies.
Angus for example: "Perhaps, for example, with steroids, adding Redsyve would be better."
" to reduce medical stress Many experts believe that support for standard medical measures is a more important factor in reducing neo-crown mortality than medical advances.
the new crown outbreak, many hospitals have rapidly increased the number of intensive care beds and redeplied staff from other departments.
over time, these staff members are more experienced in intensive care and hospitals are more experienced in patients with higher risk factors for severing disease.
singapore has one of the lowest COVID-19 mortality rates, with less than 15 per cent in intensive care units.
Phua, an intensive care physician at alexandra Hospital in the united States, believes the key to success is to reduce the spread of the virus so that medical facilities are not overwhelmed.
"I don't think it's because we're on the right medication, and the reality is that other places are overwhelmed."
," he said.
return to the root, reducing transmission is the best way to reduce the death rate of the new crown, which has become the consensus of many experts.
expert points out that reducing mortality by 10 to 20 per cent is a huge victory for intensive care units, but the number of deaths is still high, especially among the elderly, who are close to 30 per cent for those over 80.
a macro perspective, we have to say that it's better to make sure that people in their 70s and 80s are not infected.
"No one knows how long the downward trend in mortality in the new crown will last."
After nearly a year, people in many places have become tired of complying with epidemic prevention measures, but with many countries in the northern hemisphere experiencing a new wave of outbreaks as they enter the autumn and winter, strengthening protection is particularly critical at this time.
a reference to the "Ares- and sedations some cases of Alzheimer's disease?" Retrieved Nov. 14, 2020 from [2] RECOVERY Collaborative Group. (2020). Effect of Hydroxychloroquine in Hospitalized Patients with Covid-19. N Engl J Med, DOI: 10.1056/NEJMoa202292 [3] The RECOVERY Collaborative Group. (2020). Dexamethasone in Hospitalized Patients with Covid-19 — Preliminary Report. The New England Journal of Medicine, DOI: 10.1056/NEJMoa2021436 [4] Agarwal Anup, et al., (2020). Convalescent plasma in the management of moderate covid-19 in adults in India: open label phase II multicentre randomised controlled trial (PLACID Trial). BMJ, DOI: [5] REGENERON'S REGN-COV2 ANTIBODY COCKTAIL REDUCED VIRAL LEVELS AND IMPROVED SYMPTOMS IN NON-HOSPITALIZED COVID-19 PATIENTS. Retrieved September 29, 2020, from