About one in nine Canadian adults have had long-term symptoms from COVID-19 infection, according to a Statistics Canada report issued Friday.

That amounts to 3.5 million Canadians, it said.

Almost 80 per cent of those people with long-term symptoms have them for six months or more, the report said.

In addition, more than half of those who ever had long-term symptoms still had them as of June 2023.

“Among Canadians who reported ever experiencing long-term symptoms, those who continue to experience these symptoms (58.2 per cent) outnumber those who have reported them resolved (41.8 per cent),” the report said.

Long COVID, also known as post COVID-19 condition, is defined by the World Health Organization as symptoms that persist for three months or longer after infection and they can’t be explained by anything else.

The StatCan findings aren’t surprising, said Manali Mukherjee, an assistant professor of medicine at McMaster University who specializes in respiratory diseases and immunology in an interview on Friday.

“There is a subset of patients who have long COVID symptoms affecting their quality of life, their productivity on a daily level,” said Mukherjee, who is a long COVID researcher and also spent about 18 months recovering from her own symptoms.

The most common long COVID symptoms are brain fog, fatigue and shortness of breath, she said.

Two-thirds of Canadian adults who have tried to get health-care services for their long-term symptoms say they haven’t received enough treatment or support, the StatCan report said.

Research shows that getting vaccinated against COVID-19 reduces the risk of getting long COVID, as well as the severity of symptoms, Mukherjee said.