What do we really know about kids and COVID-19?

If there are two things kids are missing more than ever right now, it's seeing their friends and hugging their grandparents.

While it's too early to call good news, new research on the transmission of COVID-19 among kids is shedding a bit more light on the question of when Canadian kids may be able to safely go back to school, or finally have a visit with other adults in their lives besides their parents or caregivers. 

An Australian study published earlier this week, which has not yet been peer-reviewed, suggested transmission of COVID-19 between teachers and students is rare in schools, leading some researchers to question how necessary long-term home isolation measures are for kids.

New data emerging on schools 

Dr. Shaun Morris, an infectious disease expert at SickKids Hospital in Toronto, says shutting schools may not be as important as initially thought although it made sense early on, when less was known about how the virus was transmitted.  

"As new data is emerging, it's less clear if shutting schools is necessarily important, or if it is, how important it is," Morris told Dr. Brian Goldman, host of the CBC podcast The Dose.

"The message that was being given [in the new study] was that at least in that Australian setting, transmission within the school from children — either to other children or adults seems very rare — so I think it's not clear yet how important closing schools is," Morris said. 

Morris is part of a team that is researching underlying medical conditions of children with COVID-19 that may increase the risk for more serious disease, through a national survey of pediatricians.  

Society may need to consider the trade-off when it comes to interrupting children's education "and their ability to essentially just be normal children — to be around their friends, play with their friends," Morris said, in addition to taking into account "all of the ramifications to parents are having children at home."

Not all researchers are in agreement about the take-away from the Australian report.

Dr. Stephen Freedman, a researcher at the Care Transformation for Children Program at Alberta Children's Hospital Research Institute, and professor of pediatrics at the University of Calgary, cautions against drawing big conclusions from the Australian report.

"The study, although it's interesting and exciting and opens up an avenue of food for thought and things we need to consider, I don't actually think it tells us a lot about [COVID-19] transmission in children in general, or about transmission in schools," Freedman said.  

"The report is a bit limited in the details it provides. But it definitely is open to a lot of questions that remain unanswered at this point."

Provinces weigh opening schools 

As most schools have been closed across the country since mid-March, the question of when they can re-open has been front and centre in most provinces this week.

On Thursday, Quebec Premier François Legault announced that back-to-school plans for elementary schools, originally scheduled for May 11, are now pushed to May 25. In Alberta, school boards are considering different options, including whether students should return to school in the fall at all.

Freedman noted that research published in the journals Science and the Lancet on school closures did show some effect on flattening the COVID-19 curve, but also said the studies did not necessarily consider all the other relevant societal factors.

"School closures lead to approximately two to four per cent reduction in mortality overall," Freedman said. "And so that's the best data that I think is available out there for us to consider.

"Obviously, school closures are not the only thing that is going to reduce transmission," he said. "The other social isolation or distancing measures ... have been crucial and key to the success in regions that have flattened the curve."

Assessing risk for grandparent visits 

The question of how risky it is for grandparents and older adults to catch COVID-19 from kids with no symptoms, or perhaps very mild symptoms, is also up for debate.

Morris said that even if children do prove to be less contagious than previously thought, as the Australian study suggests, it doesn't signal a green light for grandparent visits and risks still need to be assessed. 

"You're highlighting parts of the population that are at higher risk for more serious disease should they be infected. The data that is emerging, however, seems to suggest that children are less likely to transmit COVID-19 both to other children and to adults," Morris said.

"While I do think it's a concern, particularly if you live in a household where there are at-risk people ... [such as] an elderly person or person with underlying chronic heart or lung disease, I do think that you need to be careful if there is a symptomatic child."

Freedman said the key risk factors are likely linked to the number of cases of SARS-Cov-2 — the virus that causes the COVID-19 illness— circulating in the particular community.

"Australia has done a very good job of blunting their curve, which has been pretty much flat since the end of March, early April, so they had very, very few cases," he said. "So the risk of transmission within schools is very much going to relate to the risk of — or the proportion of —  individuals that have [COVID-19] within an environment or even community," he said.

"I would suspect the risk would be higher in places like Quebec or even Ontario, where the numbers of cases are significantly higher than we're currently seeing here in Alberta at the moment."

More testing of children needed 

Ultimately, the answer to how prevalent the transmission of COVID-19 is among children in Canadian schools will come down to testing, Morris said. 

More testing is essential to understanding the epidemiology of the disease in children, which is distinct from how it affects adults, he said. 

"We simply don't have a large number of children who have confirmed cases from whom we can infer about the full spectrum of illness." 

The Public Health Agency of Canada reported that as of May 8, there were 66,434 confirmed cases of COVID-19, Fewer than 2,000 of those were people under 19 years of age. 

Top 5 things parents should know about kids during COVID-19 

Quotes from Dr. Shaun Morris, SickKids Hospital

1. Children tend to have few symptoms than adults.

"The large majority of cases of COVID-19 in children are either mildly symptomatic or asymptomatic." 

2. If your child is sick, go to the doctor or emergency department.

"Very rarely, more serious disease can happen. One of the secondary impacts of COVID that we're seeing is that some people are less likely, or feeling less comfortable, accessing the health care system, even if they're sick. If parents ever think that their child is sick, they need to either go to the emergency department, or contact the doctor."

3. Keep up routine immunizations.

"I want parents to recognize the importance of routine immunizations, particularly for young children under the age of two, and to speak to their health care providers about doing this safely and sticking as closely as possible to the routine schedule."

4. Follow recommendations made by public health experts.

"We all need to closely follow the recommendations made by our public health experts. They're the ones who are tasked with reviewing the evidence as it comes in as it changes and making the best recommendations regarding minimizing transmission and keeping us all — especially our higher risk parts of the population — safe." 

5. Don't skip the flu vaccine this year.

"Get your flu vaccine. This is important both for parents, families, and children. As we transition through the summer, and enter the fall, I think we're going to see new epidemiology with COVID-19.

What may be an issue is that we will have concurrent circulation of influenza virus and COVID-19 … Having both viruses circulating at the same time will complicate making a diagnosis because there's a big overlap in symptoms.

There is not a vaccine yet for COVID-19, but we do have vaccines that are safe and effective for influenza."