Interactive: Inside COVID’s rehabilitation hospitals A recent preprint study _ one that has not been peer-reviewed _ suggested that mild Omicron infection doesn’t render enough immunity to prevent future infections, while infections from the Delta variant, which tended to be more severe, produced higher protection.Dr.
Fahad Razak, an internist and member of the province’s science advisory table, said Ontario is not seeing “significant” numbers right now of people with more than one Omicron infection.But milder illnesses that give people congestion, cough, fever, and leave them feeling unwell but not so sick that they need to go to the hospital — like many Omicron infections — may leave people more susceptible to reinfection, he said.“The parts of your immune system that protect against those milder infections, they tend to wane much faster than the parts of your immune system that protect against the more severe infection,” Razak said.
Ontario’s top doctor ‘hopeful’ COVID-19 risk will be lower in March, April Omicron probably provides some short-term protection from reinfection, but there may not be long-term protection, said University of Toronto immunology professor Tania Watts.
The combination of vaccination and infection is much better, she said.“One thing our vaccines do is they give us what we call systemic immunity, because you inject it in the muscle, and the antibodies circulate around our body,” she said.But the reason that immunity starts to wane is that people need those antibodies in the nose and throat, where the virus enters, she said.“So when you get an infection, after two doses of vaccine, it can actually pull that immune response rapidly into the nose, and it leaves behind cells and those tissues.