By Rod Nickel
WINNIPEG, Manitoba (Reuters) - Indigenous communities in the Canadian province of Manitoba are shortening intervals between doses of COVID-19 vaccine after confirming several dozen infections after the initial jabs.
Many provinces, eager to slow a possible third wave of infections, adopted the recommendation of an advisory committee to the Canadian government this month to delay second doses for as long as four months to stretch limited vaccine supplies, with data showing protection after one dose.
But a team of health officials responsible for pandemic response for Manitoba First Nations, a term for Canadian indigenous communities, said it is seeing more infections after administering one dose than expected, possibly related to crowded housing and underlying health issues.
The response team said in a weekly bulletin it had confirmed as of last week 44 infections in people two weeks or longer after their initial doses of Moderna Inc vaccine, out of 8,875 indigenous people immunized.
It will now provide second doses about 28 days after the first, as Moderna recommends. In its large clinical trial, the Moderna COVID-19 vaccine proved nearly 95% effective at preventing illness with doses administered with the 28-day gap.
Grand Chiefs who are members of the team could not be immediately reached.
The Manitoba government, responsible for the province's broader vaccination campaign, is sticking with the longer interval based on data showing the first dose has effectively reduced infections, said Dr. Joss Reimer, medical lead for the vaccine program.
Data shows that older people and those with underlying medical conditions do not have the same robust immune response after one dose as other people, said Dr. Isaac Bogoch, infectious diseases specialist at Toronto General Hospital.
"What we'll likely see in the very, very near term is a pivot towards shortening that delay between the first and second dose for certain segments of the population," he said.
Ontario said this month it would stick to shorter intervals for remote First Nations, citing limited healthcare facilities, while delaying second doses for the broader population.
(Reporting by Rod Nickel in Winnipeg, Steve Scherer in Ottawa and Allison Martell in Toronto)