They said that it can not be assumed that people who are at lower risk of severe illness and death from COVID-19 are also at low risk of ongoing COVID.
The second study examined data from 95 critically ill people who were hospitalized with Covid-19 in Vancouver, Canada. Another study in April (pre-print and awaiting peer-review) found that among 1,559 coronavirus patients in New York City, a lower proportion than would be expected had Type O blood.
While it's still not clear whether this link is a direct cause-and-effect relationship or simply a coincidental correlation, the two new bits of research further builds on the idea that blood type might have some role in how Covid-19 affects people.
Among the COVID-19 patients, there was a lower percentage of people with blood type O and higher percentages of those with with types A, B and AB. Of the 9 patients who developed moderate to severe symptoms, 3 died.
France on Saturday reported a record rise in COVID-19 cases with 32,427 new infections registered over the past 24 hours, according to figures from the Sante Publique agency heading the coronavirus response in the country. These outcomes appear to show that notwithstanding people with Type O and Type A blood being equitably part among everyone, Type O is less powerless against the virus.
In the new study, the researchers found that patients with a genetic syndrome and adults with advanced disease from their congenital heart defect were more likely to develop moderate to severe symptoms, though an individual's type of congenital heart defect did not impact symptoms severity.
The scientists, including those from the Columbia University Irving Medical Center performed a retrospective analysis of more than 7,000 patients from the congenital heart disease center at the Vagelos College of Physicians and Surgeons in the US. The researchers caution that individuals with congenital heart disease should continue to practice strict social distancing and follow all CDC guidelines as these measures are likely contributing to the study findings.
They also found that while people with blood types A and AB didn't have longer overall hospital stays than those with types O or B, on average, they were in intensive care longer, which may indicate more severe COVID-19. "We have yet to define what those risk factors are", Anderson added.