I find it funny how some countries suddenly make your life a lot easier if you have a positive test history. Canada has a fairly annoying requirement to have a negative PCR test taken within 72h of takeoff (or arrival by car), which can be dicey/expensive in many parts of the world to get, but if you have a positive PCR result from 14-180 days, this requirement drops and travel gets a lot easier than those that never…
Why is that surprising? Recovering from a natural infection is more durable immunity than that of the vaccines. Even more so if you have both.
But if it was more durable (long-lasting), they wouldn’t have the 180d limit. They put that limit in because of the (lowwwww) risk of continuing to test positive after recovery, but the worst case report I’ve seen is in the 6 week after recovery range.
It’s mostly Canada trying to be punitive when it comes to travelling by requiring PCR, when a within-24h antigen test would be cheap, easy, catch as many asymptomatic cases as a less-fresh PCR, and near zero-risk of false positives immediately after recovery.