By Nancy Lapid
(Reuters) – The following is a brief summary of some of the latest scientific studies on the new coronavirus and efforts to find treatments and vaccines for COVID-19, the disease caused by the virus.
Full published dexamethasone trial results
The full results of a large randomized clinical trial in Britain, the gold standard of evidence, looking at the steroid dexamethasone confirm the benefits of its use in patients with COVID-19 that were hinted at in the first findings published last month. The results, published Friday in the New England Journal of Medicine, showed benefits for people with advanced or moderate disease. In total, 2,104 patients with COVID-19 were randomized to receive dexamethasone and 4,321 to receive usual care. Four weeks later, dexamethasone had reduced the risk of death by 36% among patients who needed mechanical ventilation when they entered the study, and by 18% among those who received oxygen without mechanical ventilation. The drug did not improve survival among patients who did not use oxygen or mechanical ventilation. In an editorial, Dr. H. Clifford Lane and Dr. Anthony Fauci of the US National Institute of Allergy and Infectious Diseases said the results show the crucial importance of carefully designed, large, randomized controlled trials. made. Even during a pandemic, they said, when it might be tempting to simply “give all therapies a try,” for patient outcomes to improve, “there will need to be fewer small or inconclusive studies and more studies like the dexamethasone trial.” . (https://bit.ly/2ODqKpC; https://bit.ly/2CGrZlo)
Immune cells can recognize the coronavirus years later.
Researchers in Singapore are not concerned that antibodies to the new coronavirus are rapidly fading. More important, they said, is that cells of the immune system called T cells and B cells “remember” the virus and can trigger an immune response. As reported in the journal Nature Wednesday, the researchers looked for “memory” T cells in 36 survivors of COVID-19, 23 survivors of the 2003 coronavirus that caused SARS, and 37 people who never had any of the diseases. All of the COVID-19 survivors had T cells that recognized the new coronavirus. All survivors of SARS had T cells that remembered the 2003 virus, and their T cells also recognized the new coronavirus. Furthermore, more than half of those who were never infected with any of the coronaviruses had protective T cells, suggesting that they may have found other coronaviruses in the past, and there may be some pre-existing immunity to the new coronavirus in the general population. “We found the current discussion about ‘the antibodies are fading’ a bit pointless,” three of the researchers told Reuters in a joint email. “The important thing is that a level of B and T cell memory remains to quickly start an effective immune response capable of stopping viral spread,” said Anthony Tanoto Tan of Duke-NUS School of Medicine, along with colleagues Nina Le Bert and Antonio Bertoletti. T cells can kill infected cells to slow down the virus, and they also help instruct B cells to make antibodies, the researchers said. (https://go.nature.com/2OwM9B5)
Low interferon levels identify high-risk COVID-19
Low blood levels of a type of interferon (IFN) could identify COVID-19 patients at high risk for severe pneumonia and acute respiratory distress syndrome. Interferons are natural proteins that help the body’s immune system fight infection. In a study published Wednesday in the journal Science, researchers found that severely affected COVID-19 patients had severely impaired production of IFN type I, a persistent virus in the blood, and an excessive inflammatory response. They said the findings support the potential value of treating these patients early on with IFN, combined with anti-inflammatory drugs or steroids like dexamethasone in the most seriously ill people. They also found that low plasma IFN type I levels were observed before patients began to deteriorate and required intensive care. “Circulating IFN Type 1 levels could even characterize each stage of the disease, with the lowest levels seen in the most severe patients,” they said in a press release. (https://bit.ly/398r4Xe)
Heart disease may underlie mysterious blood findings in COVID-19 patients
Severe COVID-19 predominantly affects the lungs, but elevated levels of troponin in the blood, a protein released during heart injury, are also common. For more information, cardiologists in London performed cardiovascular MRI scans on COVID-19 survivors who had at least slightly elevated troponin levels while hospitalized. Among the 29 people who have no obvious reason to elevate troponin, such as a heart attack, they found two patterns of myocarditis, or inflammation of the heart muscle. In patients with a pattern, cardiac function appeared to be unaffected. These patients should undergo cardiology follow-up to monitor for any possible long-term consequences, Dr. Dan Knight of the Royal Free Hospital told Reuters. The other pattern, seen in approximately one-third of patients, was associated with reduced blood supply to the heart or ischemic heart disease. Many patients in this group “had significant coronary artery disease that was previously unknown but required additional treatment” that would not have been offered if troponin levels had not been investigated, Knight said. Knight added that the main message is that when troponin levels are elevated in COVID-19 patients for no apparent reason, further study could reveal undiagnosed heart disease. (https://bit.ly/3958hfc)
Open https://graphics.reuters.com/HEALTH-CORONAVIRUS/yxmvjqywprz/index.html in an external browser to get a Reuters chart of vaccines and treatments under development.
(Report by Nancy Lapid; Will Dunham Edition)
