A new study suggests that a person's susceptibility to contract the Covid-19 and its severity may be linked to their blood type. Researchers at 23andMe, a genetic testing company, found people with type O blood were up to 18 per cent less likely to test positive for Covid-19 and 26 per cent less likely to contract the virus. The study involved more than 750,000 participants, including 10,000 who reported having ...