Just one month after its presence was confirmed in Manitoba, the highly contagious delta variant of COVID-19 has spread to all regions of the province.
On Tuesday, the province reported 83 cases of the B.1.617 strain first detected in India — an increase of 65 cases since last week. Most of the spread has been linked to close contacts of confirmed cases, but 13 cases are listed as occurring via community transmission and contact-tracing was still pending in another 14 cases. The delta variant cases linked to community or unknown transmission were reported to the province by Dynacare Labs, a provincial spokesperson said Tuesday.
The strain is up to 50 per cent more transmissible than the currently dominant B.117 strain, and early studies showed vaccines are less effective against it, which has led to a bigger push for the rollout of second doses. One recent study from the United Kingdom indicated two doses were 60 per cent more effective against the variant compared with just one dose.
Screening tests are still in development at provincial and federal labs to detect the delta variant faster than genomic sequencing is able to, but Manitobans need to be aware the current numbers may be an underestimation of the spread of this variant, Winnipeg epidemiologist Cynthia Carr said.
"We need to take it seriously," she said, adding Manitobans should try to get their second dose as soon as possible. Currently, all Manitobans who received their first shot on or before May 1 are eligible to book a second dose. All Indigenous people 18 and older are also eligible for a second dose.
"... I don't want this to discourage anyone from getting either their first (dose) or following up with their second dose as quickly as they're eligible." — Winnipeg epidemiologist Cynthia Carr
"Even if there is some information showing that the effectiveness of the vaccine is less, it's not zero, so I don't want this to discourage anyone from getting either their first (dose) or following up with their second dose as quickly as they're eligible. A decline in effectiveness is not a reason to think that it doesn't work at all," Carr said.
The variant is quickly becoming the dominant strain in the U.K., and is expected to account for the majority of cases in Ontario, where it has hampered reopening plans in Timmins and some remote communities. The northerneastern Ontario Porcupine Health Unit told a news conference Tuesday the region will not reopen with the rest of Ontario later this week, in part, because of community transmission of the delta variant.
The next challenge will be to keep rapidly vaccinating people, particularly vulnerable populations, before proceeding with a "slow and methodical" reopening plan to stay ahead of the delta variant, said Dr. Isaac Bogoch, a Toronto infectious diseases physician.
"It's here, we know it's spreading. It's probably, at some point, going to be the dominant variant in Canadian settings just like it is in other settings," Bogoch said.
"We know how to prevent it. We know that the vaccines work and, of course, we know that two doses of a vaccine are more effective than one. So places are vaccinating like mad as they should, getting first doses in fast, but also getting second doses in fast in priority populations as well."
"It's here, we know it's spreading. It's probably, at some point, going to be the dominant variant in Canadian settings just like it is in other settings." — Dr. Isaac Bogoch, Toronto infectious diseases physician
While Manitoba is transporting intensive-care COVID-19 patients to Ontario because of the lack of local hospital capacity, worrying about adding to Ontario's COVID burden, or the possibility of further spread of more contagious variants, shouldn't be a concern, Bogoch said.
"We truly are team Canada, and you'll get help from your friends and neighbours."
The first presumed positive case of the delta strain was announced in Manitoba in late April, and the first four cases were confirmed May 7.
— with files from The Canadian Press
Katie May reports on courts, crime and justice for the Free Press.