The U.S. National Institutes of Health’s $1 billion RECOVER Initiative has picked Pfizer Inc.’s antiviral drug Paxlovid as the first treatment it will study in patients with long COVID, organizers of the study said on Thursday.

Researchers chasing long COVID cures are eager to learn whether naltrexone, a generic drug typically used to treat alcohol and opioid addiction, can offer benefits to millions suffering from pain, fatigue and brain fog months after a coronavirus infection.

The proportion of Britain’s workforce too sick to work has jumped to its highest since 2005, which economists say is likely due to a mix of long COVID and greater difficulty in accessing health care since the start of the pandemic.

There is no authoritative data on the frequency of suicides among sufferers. Several scientists from organizations including the U.S. National Institutes of Health and Britain’s data-collection agency are beginning to study a potential link following evidence of increased cases of depression and suicidal thoughts among people with long COVID, as well as a growing number of known deaths.

Top scientists from leading academic centers are banding together to answer a key question about the root cause of long COVID – whether fragments of the coronavirus persist in the tissues of some individuals.

Panacell Biotech plans to initiate a program to investigate the use of natural killer (NK) immune cells, exosomes and brown adipose-derived stem cells to treat Long COVID.

One of the first trials aimed at tackling long COVID helped some patients recover from lingering physical and mental fatigue, although the drug developed by Axcella Health Inc failed on the small study’s main goal of restoring the normal function of mitochondria – the energy factories of cells.

Scientists have found that the presence of the SARS-CoV-2 spike protein in the plasma could be a hallmark of long COVID. The results show that the virus can linger in the body of patients who suffer from prolonged symptoms.

Nearly 1 in 5 American adults who reported having COVID-19 in the past are still having symptoms of long COVID, according to survey data collected in the first two weeks of June, U.S. health officials said on Wednesday.

The Omicron variant of coronavirus is less likely to cause long COVID than previous variants, according to the first peer-reviewed study of its kind from the United Kingdom.