COVID-19, which has killed 1.7 million people worldwide, does not follow a uniform path.

Many infected patients remain asymptomatic or have mild symptoms. Others, especially those with comorbidities, can develop severe clinical disease with atypical pneumonia and multiple system organ failure.

SARS-CoV-2 infections pose a global threat to human health and a formidable research challenge. One of the most urgent tasks is to gain a detailed understanding of the molecular interactions between the virus and the cells it infects. It must also be clarified, whether these interactions favour the multiplication of the virus or - on the contrary - activate defence mechanisms.

Understanding the body's immune response to SARS-CoV-2, the virus that causes COVID-19, is key to developing effective treatments and long-lasting vaccines. Of particular interest are neutralizing antibodies, which can block the virus from entering and infecting human cells, helping the immune system clear the virus and prevent future infections.

Female COVID-19 patients face less severe disease complications and a lower risk of dying than male patients thanks to hormones and chromosomes that contribute to a stronger immune response, according to new research from a University of Alberta-led team.

"The highlight of our study is how the sex differences in COVID-19 are linked to ACE2," said senior author Gavin Oudit, professor of medicine in the Faculty of Medicine & Dentistry, Canada Research Chair in Heart Failure and director of the Heart Function Clinic at the Mazankowski Alberta Heart Institute.

The drug remdesivir is likely to be a highly effective antiviral against SARS-CoV-2, according to a new study by a team of UK scientists. Writing in Nature Communications, the researchers describe giving the drug to a patient with COVID-19 and a rare immune disorder, and observing a dramatic improvement in his symptoms and the disappearance of the virus.

Treatment of SARS-CoV-2 infection with a new antiviral drug, MK-4482/EIDD-2801 or Molnupiravir, completely suppresses virus transmission within 24 hours, researchers in the Institute for Biomedical Sciences at Georgia State University have discovered.

The group led by Dr. Richard Plemper, Distinguished University Professor at Georgia State, originally discovered that the drug is potent against influenza viruses.

University of Minnesota Medical School and UnitedHealth Group (NYSE: UNH) researchers found that metformin was associated with significantly reduced COVID-19 death risks in women in one of the world's largest observational studies of COVID-19 patients.

Metformin is an established, generic medication for managing blood sugar levels in patients with type 2 diabetes.