If science is far from having unraveled all the mysteries of the new coronavirus, its relentless study in the four corners of the world makes it possible to better understand it day by day. Six months after the start of the pandemic, discoveries allow better care of patients and fuel the hope of a certain immunity following a first infection.
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Doubts remain about the immunity conferred by infection with SARS-CoV-2, mainly on the duration and effectiveness of this protection. However, a first study provides evidence that this immunity is possible and that it has the potential to prevent reinfection. US researchers have studied the singular case of a Seattle fishing boat hit by a major coronavirus epidemic in May. In 18 days, 104 sailors out of a total of 122 passengers fell ill on board. Everyone had been declared negative before leaving. While it is not known how the coronavirus made its way into the boat, these preliminary tests established that three sailors had neutralizing antibodies against the virus in their blood before departure, suggesting they had contracted the disease before. These three individuals are among the rare occupants not to have experienced any symptoms during their trip. For scientists, this is no accident. A first contamination would therefore be likely to guard against a second infection.
However, further studies on a larger scale will be necessary to confirm this.
Pradaxa capsules are one of the anticoagulants available on the market.
Knowing that patients with a severe form of the coronavirus develop fatal blood clots, a group of researchers and doctors in New York wanted to test whether the use of anticoagulants – substances that are used to thin the blood – could save blood. lives. The answer seems to be yes. Analyzing the records of 4,389 patients hospitalized with COVID-19, more than half of whom received anticoagulants, scientists found that this treatment was associated with a 50% reduction in the death rate. Those who were treated with blood thinners were also 30% less likely to be intubated. Bleeding, a common complication associated with anticoagulants, affected less than 3% of patients. Encouraged, the US researchers decided to go ahead with a randomized clinical trial to better understand the effect of this treatment on severe COVID-19 patients.
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A medicine that is usually given to cats to treat an infectious disease caused by a feline coronavirus could also prove very useful in combating the SARS-CoV-2 coronavirus in humans. According to researchers at the University of Alberta, two similar compounds called GC376 and GC373l, which treat this feline viral infection, prevented viral replication in cells infected with SARS-CoV-2 in laboratory tests. This opens the door to its use as a treatment against COVID-19. “This drug is very likely to work in humans, so we are encouraged,” biochemist Joanne Lemieux said in a statement. Better, as this molecule is already used in the veterinary world, and that nothing indicates that it is dangerous, the researchers will be able to skip the stage of the tests on the animal models and to pass quickly to the box of the clinical trials in the human, whose phase 1 could begin shortly.
New York researchers in a recent study found two markers in the blood of infected patients that could help predict whether they are likely to become seriously ill. Doctors affiliated with the Mount Sinai Hospital Network found that the risk of death was at least twice as high in infected individuals who had high levels of proteins called IL-6 and TNF-α, two types of cytokines. . These cytokines were associated with a high risk of complications, regardless of other factors such as an underlying medical condition, age or gender. Other studies have already shown the dangers associated with overproducing these substances when the immune system is racing. Thus, special attention should be paid to monitoring these markers in the blood of patients, in order to determine the best possible therapeutic trajectory, write the study authors. Experimental treatments like remdesivir and dexamethasone could be considered, they add, in patients for whom the prognosis is worrying.
Globally, men are estimated to account for 60% of deaths from COVID-19. Older men are also up to twice as likely to get seriously ill compared to women of the same age. As reported by New York Times at the end of August, a study made it possible to provide a hypothesis to explain this phenomenon: the immune response in men would be weaker, especially at an advanced age, than in women. This is what emerges from the study conducted at Yale University, which followed a small cohort of 17 infected men and 22 women, most of whom were over 60 years old. Most of the time, women’s bodies made more T lymphocytes, immune cells that neutralize infected cells. And this, even in elderly patients. In men, these immune cells were less effective, and their strength seemed to wane with age. Scientists say this suggests that vaccination in men, especially older men, will need to activate T cells to provide them with effective protection.
– With the collaboration of the QMI Agency