I got my sixth dose of a COVID vaccine today.

As far as I know, I have never gotten COVID. However, I may be like the 2 in 5 Canadians with antibodies from a past infection who neither tested positive for COVID nor suspected they had it. A joint survey by Statistics Canada, in partnership with the Public Health Agency of Canada and Canada's COVID-19 Immunity Task Force, found that, in the summer of 2022, 2 out of 5 Canadians were unaware that they had been infected with COVID-19 despite being found to have antibodies in their blood resulting from a past infection. Released in March 2023, the report states:

Among Canadians adults in the summer of 2022 with antibodies resulting from a past infection, 48.1% had previously tested positive for the virus at least once. An additional 10.7% with antibodies from infection suspected they had contracted the virus but never tested positive. On the other hand, 41.2% of Canadians with antibodies from a past infection never previously tested positive nor suspected an infection.

Since the start of COVID, I've been tested (via professionally administered PCR tests) and tested myself (via at-home rapid antigen tests) at least eight times, including four times last summer when all members of my nuclear family developed COVID. All my tests were negative. That's not to say that I never acquired the SARS-CoV-2 virus, only that I never developed the COVID-19 disease or, if I did, the symptoms were so mild that it didn't occur to me to do a home test.

I got today's COVID vaccination at an Ottawa Public Health community clinic, booked through the Ontario Government's COVID-19 vaccination portal. It was so efficient and well run that I had a shot in my arm within 10 minutes of entering the building for my scheduled appointment. Today's COVID vaccine complements the flu shot that I got a few weeks ago. I'd like to say I'm ready for winter, but it's going to take a few more days to adjust to the cold.