Okay - one more time. That little purple line at the bottom? That's Ontario #Covid cases from travellers (most of whom are returning Canadians). The other lines are sources the province has chosen to not control. #ONpoli #cdnpoli https://twitter.com/l_stone/status/1389736464469090304

If only the Province of Ontario published this kind of data themselves. Oh, wait. They do. #ONpoli https://covid-19.ontario.ca/data/likely-source-infection

And the inevitable push back is "The first cases came from abroad! We have to keep the variants out!" That horse has long since left the barn. The original virus arrived before we identified it. Same with variants. Unless you're a hermit kingdom, viruses will get in...

Borders cannot be hermetically sealed. What we can do (and are doing) is slow the arrival of by limiting cross-border travel. Canada has had restrictions on non-essential travel and quarantine since March 2020.

Finally, with enough infected or just bad luck, variants - even the same genetic variant - can appear in closed systems. That is the nature of mutation and successful natural selection, so an "iron ring" can help slow, but will not always prevent.

And for the Albertans out there, where Kenney is beating the same foreigner/traveller drum, here is a Govt of Alberta chart on source of recent Covid infection. See a pattern? #ableg #ONpoli

Found a historic chart of source of Covid infection in Alberta. Look familiar? https://www.alberta.ca/stats/covid-19-alberta-statistics.htm#total-cases

So, border and other mobility restrictions (like stay at home orders) are important to slow the spread of disease, but travel is a minor source of new infection. Much bigger sources are schools and workplaces which the provinces kept open.

Borders are a red herring to deflect from failures in these other areas of provincial control and refusal to act, and play on the "dirty foreigner" trope that has sadly been so effective with right-wing populist governments since the early 20th century.