Two medical studies have suggested that people with blood type O may be at lower risk of contracting the novel coronavirus.

A Danish study, conducted by 11 researchers based on information of 473,654 individuals tested for COVID-19, found that blood group O was associated with a decreased risk of coronavirus infection.

"We demonstrate that blood group O is significantly associated with reduced susceptibility to SARS-CoV-2 infection," said the study published Wednesday on Blood Advances, a peer-reviewed medical journal of the American Society of Hematology.

The research indicated that individuals with blood types A, B, and AB were also at higher risk of exhibiting thrombosis -- the clotting of blood inside a blood vessel -- and cardiovascular diseases, which are significant co-occurring conditions among hospitalized COVID-19 patients.

Similar results were found by a Canadian medical study conducted by 14 researchers based on data collected from intensive care unit patients in six metropolitan Vancouver hospitals.

"COVID-19 patients with blood group A or AB appear to exhibit a greater disease severity than patients with blood group O or B," found the study, which was published in the same journal, adding that individuals with blood group O were reported to be "less susceptible to SARS-CoV-2 infection."

The study also noted that COVID-19 patients of blood group A or AB had a higher risk of requiring mechanical ventilation and longer duration in intensive care, compared to those with blood group O or B.

While 84% of patients with blood groups A or AB required mechanical ventilation in SARS-CoV-2 infection, that level was 61% for patients with blood types O or B, according to the research.

The median length of staying in intensive care units was 13.5 days for patients with A or AB blood types, while it was only nine days for patients with O or B blood types, the study found.

Number of COVID-19 cases in the world stood around 38.5 million and deaths close to 1.1 million on Thursday, according to Johns Hopkins University data.(Text, excluding headline, courtesy Anadolu Agency)