The new Omicron subtype, which has become the dominant strain in Alberta, could cause unprecedented infections in people who already have the virus. While re-infections are possible, immunity to vaccines and antibodies from a previous infection keeps many people from serious illnesses, said Craig Jenne, an associate professor in the Department of Microbiology, Immunology and Infectious Diseases at the University of Calgary. “The good news, however, is that many of these re-infections lead to milder illness. So it’s something to look out for, but in general, it’s not necessarily something we should panic about right now,” he said. Dr Lynora Saxinger, an infectious disease doctor at the University of Alberta, said re-infections could occur in a similar way to a major vaccine discovery. “You had an immune response to that. And then, for whatever reason, that immune response is not completely protective,” he said. However, an infection from COVID can have a “self-reinforcing” effect, he noted. And for those who stuck COVID-19 during the Alpha or Delta waves, there is a “significant risk of re-infection,” he said. Although the combination of previous infection and vaccination is quite strong, Saxinger said it is possible for those infected with Omicron to get sick with the virus subtype – but it is extremely rare. “No one is going to be invincible,” he said, but except in milder cases in those who have become infected, vaccination also reduces the risk of hospitalization or death. “It’s just a game of chance now. And your particular risk is a summary of your vaccinations and infections and behaviors.”
