The arrival of the Omicron variant of concern to B.C. has coincided with what appears to be a stunning increase in COVID-19 infections.

According to CBC News senior health writer Adam Miller, B.C. data indicates that nearly 40 percent of the population "had antibodies from a previous infection in March, up from around 10 per cent in October".

This data came from analysis of thousands of blood samples in the Lower Mainland and was provided to CBC News in advance of being published.

Moreover, the data indicated that nearly two-thirds of kids under 10 are "showing evidence of prior infection. Children under five cannot be vaccinated, though that could change in the next few months.

It appears as though nearly 60 percent between 10 and 40 years of age had antibodies from prior infection, Miller reported, whereas the percentage fell to just fewer than 50 percent for those between 40 and 60 and even lower levels for those over 60.

The research was led by Dr. Danuta Skowronski, epidemiology lead of influenza and emerging respiratory pathogens at the B.C. Centre for Disease Control.

She was part of a team that reported in a 2021 preprint that two doses of COVID-19 vaccines with mixed schedules and extended dosing "gave excellent protection against hospitalization, with no sign of decline by 5-7 months post-vaccination".

However, the Omicron subvariants have evolved to infect people who are vaccinated.

Long COVID concerns rise

Skowronski was also part of a research team that posted a preprint on medRxiv last month on the physical, psychological, and cognitive profile of post-COVID condition (a.k.a. Long COVID) in Quebec healthcare workers.

(Preprints are papers that have not been published in journals after undergoing peer review.)

It showed that the lingering effects of COVID-19 infection remained high in a significant number of cases.

"Four-week and 12-week post-COVID condition prevalences of 46% (2,746/5,943) and 40% (653/1,746), respectively, were observed among non-hospitalized cases and 76% (90/118) and 68% (27/37), respectively, among hospitalized cases," the preprint stated. "Hospitalization, female sex and age were associated with higher risk."

A recent meta-analysis of 41 different studies on post-COVID condition concluded that nearly half of those who survived the disease around the world were experiencing symptoms after four months. The most common were fatigue and brain fog.

University of Michigan School of Public Health biostatistics experts pulled together this data, which was published in the peer-reviewed Journal of Infectious Diseases.

"This study finds post COVID-19 condition prevalence is substantial; the health effects of COVID-19 appear to be prolonged and can exert stress on the healthcare system," they wrote.

The upshot is if nearly two-thirds of B.C. kids under 10 have shown signs of being infected and if a significant proportion end up with one or more symptoms associated with Long COVID, this will raise questions among some parents about why there is no mask mandate in public schools.

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On March 10, provincial health officer Dr. Bonnie Henry eliminated the provincial indoor mask mandate, telling reporters that she felt that B.C. was in a good place because of its high rate of vaccination. The vaccination rate among children from 5 to 11, however, remained low at that time.

Only about 56 percent of B.C. children in this age bracket had taken at least one dose and fewer than 40 percent had received two doses.

Meanwhile, TransLink has chosen not to impose a mask mandate on its buses, SkyTrain cars, SeaBuses, and West Coast Express. That stands in sharp contrast to Ontario and some jurisdictions in other parts of the world, which have retained mask mandates on public transportation.

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