WATERLOO -- More than half of the new COVID-19 cases reported in Waterloo Region on Tuesday were in children, with 25 per cent in kids nine and younger.

In Tuesday's update, health officials reported 20 new COVID-19 cases. Of those, eight are in youth between the ages of 10 and 19, with five cases in children nine and younger.

"It's really not a surprise that you are seeing cases in the younger generation," said Ryan Imgrund, a biostatistician who works with several public health units in Ontario.

"As we get more and more people vaccinated, especially those that are vaccine eligible, the 12 and over population, what's going to happen is that cases link into the under 12 population."

Health officials in Waterloo Region say the new cases among youth and teens highlight the importance of everyone getting vaccinated.

"It is important that everyone who is eligible get vaccinated as soon as they can because children under 12 are not yet eligible," a spokesperson for the region said in an email.

With the start of school only four weeks away, the province's top doctor says COVID-19 cases will go up in the fall, with how high they soar depending on each community's vaccination rate.

"We do anticipate that there are different regions affected given that Ontario has different immunization rates, some communities are achieving very, very high protection and may be spared any significant rise in cases," Dr. Kieran Moore, Ontario's chief medical officer of health, said at a press conference Tuesday.

In Waterloo Region, more than 83.8 per cent of residents 12 and older have received at least one dose, while 73.91 per cent of the eligible population is fully vaccinated.

Children under 12 are still not eligible for a COVID-19 vaccine. In Waterloo Region, that's about 82,000 people.

Although children will be required to wear masks when they return to school, some are concerned there's no plan released by the province yet on how to handle COVID-19 cases in the classroom.

"The most important stuff, which is on contact tracing and case management, we don't have that information yet and we're only a few weeks away from school," Imgrund said.