Ontario is now measles free, the health minister said Thursday, as a new report raised questions about how immunization rates are tracked in the province.

The incubation period for measles is between seven and 21 days, so with the last case being reported Feb. 20, the outbreak appears to be over, Eric Hoskins said Thursday.

"We are now — knock on wood — we are measles free in the province," he said.

There were fewer than 20 cases in Ontario — in the Toronto and Niagara regions — compared to 119 cases in Quebec. Measles is highly contagious and causes fever, a distinctive red rash and a runny nose.

A report on vaccination policy from the C. D. Howe Institute, released Thursday, became the third recently released report to express concerns about how vaccinations are tracked in the province.

Ontario and a few other provinces are using a system called Panorama to track childhood immunization, but the auditor general and C. D. Howe expressed concern that it won't be fully effective unless immunization is tracked across all Ontarians' lifespans.

The $160-million Panorama system — a cost the auditor general notes ballooned from $85 million — started rolling out in Ontario in August 2013 and is now in use at all but one of the public health units.

But the lack of automatic enrolment in the system at birth means it's hard to encourage vaccination early in life, "potentially leaving infants vulnerable," the C. D. Howe report concluded.

"Although Ontario's vaccination schedule for newborns begins at two months, and many parents begin to vaccinate their children at that time, data are not officially recorded until a child enters school," the report said.

In Ontario children enrolling in primary or secondary school must be immunized against specific diseases unless their parents obtain exemptions for medical, religious or "conscience" reasons.

The auditor general found last year that Ontario lacks information on immunization rates in licensed daycares because public health units often don't report the information to the health ministry and the ministry doesn't request it. And there is no process to ensure vaccination of adult immigrants, Bonnie Lysyk said.

"Panorama will not provide the data needed to identify areas of the province with low immunization-coverage rates, which could help prevent future outbreaks and identify vulnerable people during an outbreak," Lysyk found.

But Hoskins said Panorama was helpful during the recent measles outbreak in determining the vaccination status of people who reported measles-like symptoms. The province expects public health units to report daycare immunization rates, he said.

"So I think we've got a very comprehensive surveillance program and reporting program through our public health units," Hoskins said.

A panel of medical experts that reviewed the immunization system last year also concluded that Ontario is missing opportunities to monitor and potentially intervene to promote vaccination in the first few years of life.

A "truly comprehensive" immunization registry would accurately track all vaccines administered to all Ontarians throughout their lives, with linkages to electronic medical records, said the review.

"The public and their providers should have electronic access to their own immunization records and immunization reminders to help them follow the recommended immunization schedule," it concluded.