Since the Wuhan coronavirus first appeared late last year, researchers have been studying it, though for the first month or so, only Chinese scientists had access to the data.
But now that China has shared its data with the world, research has been appearing more quickly, with more opportunities for peer review.
According to a study published in the Lancet on Friday, patients who are especially vulnerable to severe COVID-19 infections - a group that includes the very old, very young and those with co-occurring conditions - die at a higher rate from COVID-19 than they did from SARS and MERS.
A study of 52 critically ill adults at Wuhan Jin Yin-tan hospital found that 61.5% of patients requiring hospitalization and intense monitoring ended up becoming "non-survivors", to borrow some of the researchers' terminology.
The researchers concluded that COVID-19 - or SARS-CoV-2, as they call it - is more lethal for vulnerable patients than SARS or MERS was.
Like SARS-CoV and Middle Eastern respiratory syndrome (MERS)-CoV, SARS-CoV-2 is a coronavirus that can be transmitted to humans, and these viruses are all related to high mortality in critically ill patients.12 However, the mortality rate in patients with SARS-CoV-2 infection in our cohort is higher than that previously seen in critically ill patients with SARS. In a cohort of 38 critically ill patients with SARS from 13 hospitals in Canada, 29 (76%) patients required mechanical ventilation, 13 (43%) patients had died at 28 days, and six (16%) patients remained on mechanical ventilation. 17 (38%) of 45 patients and 14 (26%) of 54 patients who were critically ill with SARS infection were also reported to have died at 28 days in a Singapore cohort13 and a Hong Kong cohort,14 respectively. The mortality rate in our cohort is likely to be higher than that seen in critically ill patients with MERS infection. In a cohort of 12 patients with MERS from two hospitals in Saudi Arabia, seven (58%) patients had died at 90 days.15 Since the follow-up time is shorter in our cohort, we postulate that the mortality rate would be higher after 28 days than that seen in patients with MERS-CoV.
Researchers presented their findings in a series of tables which clearly broke down each patient's symptoms and path to recovery (or death).
The mean age of the 52 patients who participated in the study was 59 years old. 35 (67%) were men, 21 (40%) had been diagnosed with some kind of chronic illness, and 51 (98%)were found to have a fever.