About 400mln people worldwide have had long Covid-19, research

Young multi-ethnic team during coronavirus lab tests. [Getty Images]

About 400 million people worldwide have been afflicted with long Covid-19, according to new research.

The estimated economic cost, from factors like health care services and patients unable to return to work, is about 1 trillion U.S dollar globally each year, or about 1 per cent of the global economy, according to the research, published on Friday in the journal Nature Medicine.

The research is an effort to summarize the knowledge about and effects of long Covid-19 across the globe four years after it first emerged.

It also aims to "provide a road map for policy and research priorities," said one author, Ziyad Al-Aly, the chief of research and development at the V.A. St. Louis Health Care System and a clinical epidemiologist at Washington University in St. Louis.

Al-Aly wrote the paper with several other leading Covid-19 researchers and three leaders of the Patient-Led Research Collaborative, an organization formed by long Covid-19 patients who are also professional researchers.

Other conclusions include that about 6 per cent of adults globally have had long Covid-19; many people have not fully recovered; and treatment remains one of the biggest challenges.