New federal modelling data shows severity indicators and daily cases of COVID-19 are back on the rise, with incidents highest among young adults.

Chief public health officer Dr. Theresa Tam says daily cases have increased more than 30 per cent over the past two weeks, with an average of 29 deaths reported daily.

Tam says that indicates we're in a ``very tight race'' between vaccines and variants of concern, which make up an increasingly high proportion of new cases in several provinces.

The data released today by the Public Health Agency of Canada shows that while the number of cases have declined in Canadians aged 80 and older, incidence rates are highest among young adults aged 20 to 39.

Tam says infections among younger, more mobile and social age groups pose an ongoing risk for spread into high-risk populations, and continuing community spread.

More than 7,100 cases of variants of concern have been reported across the country, with the variant first identified in the U.K. making up 90 per cent of those cases.

Tam adds that there are emerging concerns of the increased severity of this variant in adults.