Why coronavirus hospitalization rates are lower so far in the second wave

The second wave of the coronavirus has come back bigger than the first, with the number of new cases reaching all-time highs across the country in recent weeks.

But so far, the second wave has been less lethal and far fewer Canadians are ending up in hospital.

Canada has long surpassed the rates of infection seen in April and May, data shows. During the peak of the first wave, the new case total was below 2,000 per day. By comparison, in the last week, Canada has recorded an average of 2,747 new cases per day.

Yet the number of people falling ill enough to become hospitalized is dramatically lower than it was in the spring.

Currently, more than 1,100 Canadians are hospitalized with COVID-19, according to provincial government statistics. Earlier this year, there were as many as 3,000 at a time.

Similarly, while the national death toll has hit 10,000 and continues to rise, fewer deaths are occurring daily than in the first wave.

Dr. Theresa Tam, Canada’s chief public health officer, has said there can be a lag of several weeks between case spikes and increases in deaths and hospitalizations. While health-care systems are currently under strain in some areas, the full impact of the dramatic uptick in cases may not be known yet.

The stark difference between the first and second wave is also a reflection of who’s getting infected and how vulnerable they are.

At a press conference on Friday, Tam said the lower hospitalization rates may be partially due to the younger age of cases in recent months, combined with better treatment options.

“However, this situation can change and it depends on the vulnerability of the populations impacted and the capacity of the health-care system in affected areas,” she said.

The age group with the most cases is 20- to 29-year-olds, followed by 30-to 39-year-olds, Health Canada data shows. People between those ages account for a third of all cases overall, but make up only about 7.6 per cent of hospitalizations and only 0.3 per cent of fatalities.

“They don’t suffer the serious illness at quite the same rate,” said Timothy Sly, an epidemiologist and professor emeritus at Toronto’s Ryerson University. “So while the cases are going up, the hospitalizations are staying roughly the same, or they’re going up at a much slower rate.”

During the first wave, the virus had a devastating impact on seniors. More than 1,000 long-term care and assisted living facilities throughout the country suffered outbreaks, and in Ontario and Quebec, the military was called in to help out at homes in crisis.

During that wave, about 80 per cent of those who lost their lives to COVID-19 in Canada lived in care facilities.

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Cynthia Carr, epidemiologist and founder of Epi Research in Winnipeg, said the stark difference between how COVID-19 affects younger and older age groups can give some people a false sense of security.

“Younger people need to remember that they are the ones that can potentially lead to a very serious health outcome in an older person,” she said.

While so far, hospitalizations and deaths are down relative to the spring, the numbers are still headed in the wrong direction and the disease is increasingly being diagnosed within the most vulnerable populations.

Cases in care homes are continuing to occur this fall, with 83 active outbreaks in Ontario alone.

“We’re now seeing a concerning rise in incidents among individuals 80 years of age and older,” Tam said.