What to know as respiratory illness season begins in Ontario

Infectious diseases specialist Dr. Isaac Bogoch on how to protect yourself during cold and flu season.

With kids back in school and the weather getting cooler, it’s that time of year when many illnesses, particularly respiratory illnesses, start to make a comeback.

While we no longer need to behave as if we’re in a pandemic, experts say, lots of viruses and germs are still circulating out there.

“Now is the time to think about how we can protect ourselves from these respiratory illnesses and sort of come up with plans for ourselves and our family,” says Dr. Pierre-Philippe Piche-Renaud, a staff physician at the Hospital for Sick Children’s Division of Infectious Diseases.

According to Toronto Public Health (TPH), the main viruses expected to circulate this fall include COVID-19, influenza (flu), Respiratory Syncytial Virus (RSV), and measles.

Here’s what to know about each of them, as well as tips for avoiding them and staying healthy.

COVID-19

While COVID-19 is no longer shutting down society, it continues to circulate.

“COVID-19 rates have already started to rise throughout the late summer, and they’re going to very likely continue to rise in the community throughout the fall, peaking sometime in the early winter, as they’ve done for the last couple of years,” says Dr. Isaac Bogoch, an infectious diseases specialist at the University Health Network.

That’s not necessarily cause for alarm, Bogoch points out, since respiratory illnesses have ramped up seasonally “since the dawn of time” and this year will likely be no different.

“Obviously, COVID has changed dramatically over the last five years, and it’s not nearly the same disease that it once was, for example, earlier on in the pandemic,” Bogoch says.

Since late 2022, the world has been in the “Omicron era,” Bogoch says. Part of those changes, he points out, is that the vaccines are not quite as effective as they once were against blocking infection and preventing transmission.

“It (a vaccine) does it to a smaller extent and for a shorter duration, so it’s not nothing,” Bogoch says. “But really, the heavy lifting of the vaccine is to prevent and reduce the risk of severe manifestations of the virus, like hospitalizations and death.”

Because of those changes, he says, the National Advisory Committee on Immunization (NACI) has changed its advice around who should get vaccinated, and who may get the vaccine if they wish.

“So essentially, they have two categories; people who ‘should’ get vaccinated, and then people who ‘may’ get vaccinated,” Bogoch says. “And in the ‘should get vaccinated’ crowd is really people who have the greatest risk for severe illness, meaning hospitalization and death.”

That includes people over the age of 65, long-term care home or chronic care residents, and people with underlying health conditions, such as those undergoing chemotherapy or who are on immunosuppressants – that put them at greater risk for severe illness.

A decision around whether to get the vaccine because you are in close proximity to someone who is vulnerable comes down to “a bit of a value judgment,” Bogoch says, where each case might need to be decided based on the individual context.

Influenza (flu)

Influenza can similarly be dangerous for those who are in the higher risk group for serious illness from respiratory infections.

The provincial government announced Sept. 18 that the province will begin rolling out COVID-19 and flu vaccinations this month for or high-risk and priority groups.

“As we head into the fall, it’s important that we take simple, effective steps to stay healthy,” Dr. Kieran Moore, Ontario’s chief medical officer of health, said in a statement. “Staying up-to-date on seasonal vaccines is significant to protect yourself, your family and loved ones and is a cornerstone of our preparedness this respiratory season.”

Ontario is beginning a phased rollout of vaccines, beginning with high-risk groups, starting the week of Sept. 22. That’s when COVID-19 vaccines will be available for the first priority groups. Flu vaccines will be available starting the week of Sept. 29.

The first round of vaccines will be available to hospitalized patients, hospital staff, residents and staff in long-term care homes, retirement homes and other congregate settings and those aged 65 and older.

Free flu and COVID-19 shots will be available to the general public at some pharmacies, public health units and participating doctor and nurse practitioner offices starting on Oct. 27.

Respiratory Syncytial Virus (RSV)

Vaccines against Respiratory Syncytial Virus (RSV), another respiratory illness most dangerous for babies and older people, are being expanded this year through Ontario’s adult RSV prevention program.

“There’s good clinical trial data demonstrating that this reduces the risk of severe illness,” Bogoch says. “People can still get the infection, but it reduces the risk of severe illness, especially in those at greatest risk.”

Starting the week of Sept. 22, Ontario residents aged 60 to 74 who meet certain high-risk criteria or live in specific higher-risk settings, as well as those aged 75 and older, are eligible to receive the RSV vaccines Abrysvo and Arexvy.

Newborns and infants up to eight months of age in their first RSV season and high-risk children up to 24 months of age in their second RSV season can receive the Beyfortus vaccine starting on Oct. 1. Those who are pregnant can also receive Abrysvo to protect their babies.

“The interesting thing about this vaccine is that it looks like the efficacy of the vaccine is much longer than other vaccines like influenza and COVID, and it looks like this lasts at least two years. So that’s that’s pretty helpful,” Bogoch says.

Measles

After many years of little activity, Ontario has seen a large measles outbreak this year.

Measles is a highly contagious respiratory infection that spreads through the air, with symptoms starting seven to 21 days after exposure. The symptoms include high fever, cough, runny nose, red watery eyes, and a red rash that typically starts on the head and neck.

As of Sept. 16, Ontario has reported a total of 2,375 measles cases since the province’s first outbreak cases were identified in Oct. 2024.

While the situation has improved, new cases continue to crop up, including a new measles case announced in Vaughan on Sept. 18.

“We’re not seeing as many cases as we used to a couple of months ago, but it’s still a good time to ensure that children who are eligible to receive measles vaccines are indeed appropriately vaccinated, because Measles is extremely contagious,” Piche-Renaud says.

“We saw last season what can happen when a couple of cases are introduced to the province.”

Bogoch echoes that idea and points out that there is an “extraordinarily effective” vaccine against the illness, which can be serious or even deadly.

“It would be exquisitely rare for a child or adolescent to acquire measles if they were up to date on their routine childhood immunizations,” he says. “So if parents are worried that their kid might get measles in a classroom, and if that child is vaccinated for measles, the likelihood of infection is negligible.”

How to stay healthy

Doctors say the first step is making sure that people are up-to-date on their regular immunizations.

“Everyone should be up to date on their routine childhood immunizations. That’s step one,” Bogoch says. “There’s routine childhood immunizations, and then there’s sort of seasonal immunizations, but the routine childhood immunizations – for example, measles, mumps, rubella, pertussis – these are routine childhood immunizations, and they’re extraordinarily effective.”

Piche-Renaud agrees and says that while it’s difficult to predict how the fall and winter will go, doctors expect to see the usual suspects and immunizations are an easy first step to prevent serious illness.

“These vaccines are important, the seasonal vaccines, but also to ensure that children are up to date with not only these seasonal vaccines, but their routine immunizations,” he said.

And while colds and respiratory illnesses will occur this season, doctors say basic infection-prevention measures can help prevent the spread to others when people do have symptoms like coughs, runny noses and fevers.

“When experiencing these kind of symptoms, people can still be contagious, so if it’s impossible for you to stay home when you’re experiencing these symptoms, ensure that hand hygiene is in place, in addition to wearing masks, for example, in public spaces,” Piche-Renaud says.

Toronto Public Health offers similar advice, saying people should stay home when sick, wash hands often, and cover coughs and sneezes. The agency also advises people to consider wearing a well-fitted mask in crowded spaces as virus circulation ramps up.