As temperatures drop and more Canadians head indoors, the familiar sniffles, aches and pains may soon follow, signaling the arrival of cold and flu season . In Canada, flu season typically runs from November to April, and while anyone can catch the flu, the virus can sometimes lead to severe complications — even death, which is why experts stress the importance of the annual flu shot. In preparation, some provinces are rolling out this year’s influenza shot over the next few weeks, beginning with vulnerable groups before expanding to the general public.

The dominant strain this year is expected to be influenza H3N2, with some H1N1 and influenza B circulating as well, though not in excessive amounts, according to Gerald Evans, an infectious disease specialist at Queen’s University in Kingston, Ont. “We have a fair bit of data from South America, Australia and New Zealand showing it’s an H3N2 year,” he said, adding that what happens in the Southern Hemisphere usually lays the groundwork for predicting which viruses are out there by the time they make their way north. H3N2 is a form of influenza A and tends to cause more severe illness, particularly in older adults, young children and those with weakened immune systems.

It’s not just influenza that Canadians need to worry about — fall and winter also bring a rise in other respiratory illnesses, including rhinovirus (the common cold), respiratory syncytial virus (RSV), and COVID-19. Here is a look at what may be i.