By Steve Scherer and Julie Gordon

OTTAWA (Reuters) – COVID-19 variant cases are increasing rapidly in several parts of Canada and longer-range forecasts show that stronger public health restrictions will be required to counter the spread of the disease, health officials said on Friday.

Canada is expecting enough coronavirus vaccine doses to double its supply by the end of next week as it ramps up its vaccination program. But more transmissible variants now account for a high proportion of new cases, health officials said.

“Increasing case counts, shifting severity trends and a rising proportion of cases involving variants of concern is a reminder that we are in a very tight race between vaccines versus variants,” Canada’s chief medical officer, Theresa Tam, told reporters.

While Canada has handed out first shots to many of the most vulnerable and very elderly, recent data shows that young adults between 20 and 39 years of age are driving new cases now, health officials said.

Many parts of the country have begun to relax some health restrictions put in place to beat back a second wave, but Tam said Canadians should buckle down now to avoid a sharp rise in cases and a third wave.

“We are closer now than ever, but it is still too soon to relax measures and too soon to gather in areas where COVID-19 is still circulating in Canada,” Tam said.

“So as Passover, Easter and Ramadan approach, make plans to celebrate safely, including having virtual celebrations to protect each other as we make this the last big push to keep the path clear for vaccines,” she said.

As of Thursday, Canada had reported 22,790 deaths and 951,562 total coronavirus cases. On Friday, the officials told reporters that new modeling showed the domestic death toll could rise to between 22,875 and 23,315 by April 4, with total cases rising to between 973,080 and 1,005,020.

(Reporting by Steve Scherer and Julie Gordon; editing by Jonathan Oatis)