CALGARY -- With school-aged children now making up about a quarter of Alberta's active COVID-19 cases, the provincial government is re-implementing some of the health measures it dropped ahead of the school year. 

Premier Jason Kenney was joined by the ministers of education and health Tuesday afternoon to announce Alberta will again implement contact tracing in schools and will publicly report online when a school population has at least two cases of COVID-19. 

Entire classrooms will also be ordered to move to online learning for 10 days when three or more cases are found in a classroom within a five-day period, Chief Medical Officer of Health Dr. Deena Hinshaw announced. 

“This fourth wave has made things challenging, especially for the families of children who are not yet eligible for the COVID-19 vaccine, and certainly for our schools," said Education Minister Adriana LaGrange.

Contact tracing will not begin until Oct. 12, after the Thanksgiving long weekend, and will be school-directed for at least a month, until Alberta Health Services has hired back enough staff to take over the work.

Rapid testing will also be offered to students in schools with at least 10 cases of COVID-19. Parents will be able to request rapid tests from their child's school and can administer them at home. Six million rapid tests are on order, the province said. 

The additional health measures are needed to ensure in-person learning can continue safely, said LaGrange, but critics say the province moved far too slow. 

"Really, any measures they put in now is great, but they're really too little, too late," said Medeana Moussa with the group Support Our Students. 

"The case numbers in schools were completely foreseeable and that this government took so long to act is another example of their failure in leadership and their failure to prioritize students." 

The province will not implement a mandatory vaccine policy for school staff, instead opting to write a letter to school boards encouraging them to do so. 

Shortly before the government's announcement Tuesday, the Calgary Board of Education said it will require all of its employees and volunteers to be fully vaccinated against COVID-19 by Dec. 17. 

The Alberta Teachers' Association (ATA) is calling for the government to make vaccines required for all education staff and say the measures announced Tuesday don't go far enough.

"These were measures that should never have been dropped to begin with and are measures we were asking to be reinstated at the start of the school year," said ATA president Jason Schilling.

"Now we find ourselves in a mess with a lot of cases within our buildings that we need to try to mitigate."