As Ontario hospitals warn of a possible "disturbing" new trend in hospitalizations among infants, doctors are urging parents to be vigilant when monitoring for COVID-19 symptoms in children, and to get vaccinated if pregnant.

Dr. Nadia Alam, a family doctor and anesthetist from Halton Hills, Ont., told CTV News Channel on Thursday that with the Omicron variant of COVID-19 as prevalent as it is, and far more transmissible than the Delta variant, more people will get sick, and some more than others.

Two Ontario children’s hospitals in Ottawa and Hamilton said this week that they have admitted six babies under 12 months old due to COVID-19, a rare occurrence until now in this pandemic.

Newborns have immature immune systems, which Alam said make them more vulnerable and could help explain why more are coming down with COVID-19.

Studies suggest antibodies from the COVID-19 vaccine pass from the mother, giving their babies protection. However, a baby whose mother is unvaccinated or hasn't been previously infected also wouldn't receive the protection of maternal antibodies.

Children under five years old are currently ineligible to receive a COVID-19 vaccine in Canada.

"What parents need to do is to realize they're not helpless," Alam said.

She said parents can ensure they themselves and those they know are vaccinated, follow public health protocols and learn to identify the symptoms of what could be COVID-19.

These include runny nose, cough, sore throat and fever, but other red flags in newborns may be if a baby looks and feels lethargic, is dehydrated, has sunken eyes and is producing fewer than five wet diapers a day, Alam said.

For children over the age of one, other red flags may include being unable to control a fever with Tylenol or Advil, not drinking enough fluids, barely eating, vomiting, severe diarrhea, dry tacky mouth and tongue, listlessness or trouble breathing.

These signs, she said, would be reasons to seek medical attention, including in the emergency department if symptoms are more severe.

"Circling those wagons and protecting those who cannot be protected, looking out for them, becomes of paramount importance," Alam said.

Although young people can still contract SARS-CoV-2, the virus that causes COVID-19, severe illness, hospitalization and death remain exceedingly rare.

As of Thursday, there have been more than 123,000 resolved cases of COVID-19 in people under 20 years old in Ontario and a total of nine deaths. There are nearly 23,000 active cases currently in that age group.

While more children and young people are being hospitalized, Dr. Earl Rubin, director of the infectious diseases division of the Montreal Children's Hospital, told CTV National News this is simply because the virus is "everywhere" right now, and symptoms in kids remain mostly mild.

"We are seeing an increasing number of children admitted who are COVID positive. However, at least half of them are not admitted for COVID-related reasons," Rubin explained.

He added that those children who do require medical care are staying in hospital for less time than what we have seen in previous waves of the pandemic.

Speaking to CTV's Your Morning on Friday, infectious disease specialist Dr. Isaac Bogoch in Toronto said while children can get sick, most do not.

"When you look at the rate of significant illness or severe illness in kids versus adults it's miniscule," he said. "The problem is you have so much infection and such a burden of infection in the community that these very rare events suddenly don't look so rare anymore."

Asked about the prevalence of lingering dry coughs after someone recovers from COVID-19, Bogoch said this is extremely common and can take weeks to resolve. As long as other symptoms have improved and a person has waited the appropriate amount of time to recover, they can go back to work, he said.

VACCINES AND PREGNANCY

The advice comes as multiple Ontario hospitals released a joint statement on Wednesday encouraging those who are pregnant to get vaccinated against COVID-19 in order to protect themselves and their baby.

The statement from the Children's Hospital of Eastern Ontario (CHEO) in Ottawa, The Hospital for Sick Children in Toronto, McMaster Children's Hospital in Hamilton, Ont., and Kingston Health Sciences Centre says hospitals are starting to see a "disturbing, potential new trend" of COVID-19 admissions in infants with the rise of Omicron.

Since mid-December, CHEO and McMaster Children's Hospital have admitted six babies under 12 months old due to COVID-19, something that would have been a "rare occurrence" previously, the statement says. At CHEO, the statement says all of the admitted infants' mothers were unvaccinated.

The hospitals add that data from CHEO, as well as from other jurisdictions and countries, have found no evidence that COVID-19 vaccination during pregnancy is associated with any adverse outcomes.

Dr. Peter Juni, scientific director of Ontario's COVID-19 Science Advisory Table, told CTV News Channel on Thursday that the idea COVID-19 vaccines will negatively affect pregnancy or fertility is "all a lie."

"But what it results in, this lie, is that we have worldwide basically a lot of women who are fertile, who have become pregnant, et cetera, not vaccinated and it results in absolutely preventable tragedies," he said.

Juni added that the risk of ending up in hospital or intensive care for those who are unvaccinated is roughly 10-20 times higher than those who are fully vaccinated.

The Ontario government reported 2,279 people in hospital due to COVID-19 on Thursday, matching some of the record highs seen back in April.

According to health officials, 20 more deaths related to COVID-19 were reported, including two children, both under the age of 10.

Thursday’s figure includes 307 people in intensive care units (ICU), which is still below the highs of more than 800 seen in the spring.

Those who are unvaccinated or partially vaccinated currently make up about two-thirds of those in Ontario ICUs.

Some evidence has shown that Omicron, while more transmissible than the Delta variant, is less likely to result in severe illness or death, particularly for those who are fully vaccinated. However, health officials have raised concerns that the sheer number of new cases each day, as well as infections among health-care workers, could still strain the province's hospitals.

"We really have to brace ourselves," Dr. Lisa Salamon, a family and emergency room doctor in Toronto, told CTV News Channel on Thursday.

"I think we have to stop this narrative that it's mild, that people aren't getting sick, because we are now seeing a lot more patients being hospitalized and going into the ICU and the number is really increasing exponentially."

With a file from CTV National News' Heather Wright