The following is a brief summary of some of the latest scientific studies on the novel coronavirus and efforts to find treatments and vaccines for COVID-19, the disease caused by the virus.
Full results of the dexamethasone study published
The full results of a large randomized clinical trial in the UK – the gold standard of testing – for the steroid dexamethasone confirm the benefits of its use in COVID-19 patients, as highlighted in the early results released last month. The results, published in the New England Journal of Medicine on Friday, showed benefits for people with advanced or moderate illness.
A total of 2,104 COVID-19 patients were randomly treated with dexamethasone and 4,321 patients received the usual treatment. Four weeks later, dexamethasone had reduced the risk of death by 36% in patients who required mechanical ventilation at the start of the study and by 18% in patients who received oxygen without mechanical ventilation.
The drug did not improve survival in patients who did not use oxygen or mechanical ventilation.
In an editorial, Dr. H. Clifford Lane and Dr. Anthony Fauci of the U.S. National Institute of Allergy and Infectious Diseases said the results demonstrate the vital importance of large, well-designed, carefully conducted, randomized, controlled trials.
Even during a pandemic, they said, fewer small or inconclusive studies and more studies, such as the dexamethasone study, would need to be undertaken if it could be tempting to "give all therapies a chance" to improve patient outcomes . "
Immune cells can recognize the coronavirus years later
Researchers in Singapore are not afraid that antibodies to the novel corona virus will fade quickly.
It is more important that cells of the immune system, so-called T cells and B cells, "remember" the virus and can trigger an immune response. As reported on Wednesday in the journal Nature, researchers looked for "memory" T cells in 36 COVID-19 survivors, 23 survivors of the 2003 coronavirus that caused SARS, and 37 individuals who had neither disease.
All COVID-19 survivors had T cells that recognized the new coronavirus. The SARS survivors all had T cells that remembered the 2003 virus – and their T cells also recognized the new corona virus. In addition, more than half of those who were never infected with either coronavirus had protective T cells, suggesting that they may have encountered other coronaviruses in the past and that some immunity may already have been found in the general population against the new corona virus.
"We find the current discussion about" antibody fading "a little pointless," three of the researchers said in a joint email to Reuters.
"It is important that a level of B and T cell memory remains in order to quickly trigger an effective immune response that can stop the spread of viruses," said Anthony Tanoto Tan from Duke-NUS Medical School together with colleagues Nina Le Bert and Antonio Bertoletti. T cells can kill infected cells to slow the virus down, and they also help direct B cells to produce antibodies, the researchers said.
Low interferon levels characterize COVID-19 with high risk
Low blood levels of one type of interferon (IFN) could identify COVID-19 patients at high risk for severe pneumonia and acute respiratory distress syndrome.
Interferons are naturally occurring proteins that help the body's immune system fight infections. In a study published on Wednesday in the journal Science, the researchers found that seriously and critically ill COVID-19 patients had severely affected the production of IFN type I, the persistent virus in the blood and an excessive inflammatory response.
They said the results support the potential value of early treatment of these patients with IFN in combination with anti-inflammatory drugs or steroids such as dexamethasone in the seriously ill.
They also found that low Type I IFN plasma levels were observed before patients started to worsen and needed intensive care. "Circulating type 1 IFN levels could even characterize any stage of the disease, with the lowest levels being seen in the heaviest patients," a press release said.
Heart disease can cause mysterious blood results in COVID-19 patients
Heavy COVID-19 mainly affects the lungs, but elevated blood levels of troponin, a protein released during a heart injury, are also common.
To learn more, cardiologists in London performed cardiovascular magnetic resonance imaging on COVID-19 survivors who had at least slightly elevated troponin levels in the hospital. Among 29 people with no obvious reason for an elevated troponin such as a heart attack, they found two patterns of myocarditis or myocarditis.
Cardiac function did not appear to be impaired in patients with a pattern. These patients should undergo a cardiological follow-up to determine possible long-term consequences, said Dr. Dan Knight of the Royal Free Hospital told Reuters.
The other pattern, seen in about a third of the patients, was associated with reduced blood supply to the heart or ischemic heart disease.
Many patients in this group "had an important coronary artery disease that was previously unknown but required further treatment" that would not have been offered without the troponin level study, Knight said. Knight added that the main message was that if the troponin levels in COVID-19 patients were raised, further work-up could reveal an undiagnosed heart disease for no apparent reason.
Open https://graphics.reuters.com/HEALTH-CORONAVIRUS/yxmvjqywprz/index.html in an external browser to get a Reuters graphic of vaccines and treatments in development.
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