Experts warn that new COVID-19 data on vaccination status may not show whole picture

TORONTO -

Ontario is now releasing daily reports that disclose how many COVID-19 cases, hospitalizations and ICU admissions are among unvaccinated, partially vaccinated and fully vaccinated people, which health experts applaud while warning that context is critical.

At 10:30 a.m., the province released the first set of this new daily data. Until now, the province has released daily case numbers, hospitalizations and deaths, but without providing a breakdown of vaccination status.

“Thanks to the protection offered by vaccines, growing case counts will not have the same meaning as they did earlier in the pandemic. Hospitalization and ICU admissions will be the key indicators,” the province said in a statement.

According to the province’s data, of the 100 people hospitalized due to COVID-19, 28 people are unvaccinated, 20 are partially vaccinated and 12 are fully vaccinated. In the ICU, the province said nine people are unvaccinated, four people are partially vaccinated and three people are fully vaccinated.

The data released today appears to include discrepancies in hospitalizations and COVID-19 cases, which the province has said are due to “records with a missing or invalid health card number [that] cannot be linked.” The provincial website also reads, “data quality will continue to improve as hospitals continue to submit data.”

“I do think this is a good start,” infectious diseases specialist Dr. Sumon Chakrabarti said. “We haven’t had any of this, just the case count by itself.”

In order to understand this new data, Dr. Chakrabarti said we need to look at the full picture.

“These numbers can tell a completely opposite story if you don’t look closely,” he said.

As the proportion of the population that is vaccinated grows and the number of unvaccinated individuals shrinks, Dr. Chakrabarti said the fact that a much greater proportion of the population is vaccinated must be taken into account when we look at the breakdown of individuals who are contracting the virus.

According to the province’s Chief Medical Officer of Health Dr. Kieran Moore, 81 per cent of those 12 and older have received their first dose of a COVID-19 vaccine in Ontario and nearly 75 per cent are fully protected.

“If 99 per cent of people are vaccinated in the province, of course when people are admitted to hospital, you are going to see a lot of vaccinated people, because the number of unvaccinated people is so small,” Dr. Chakrabarti said.

Neuroscientist and science communicator Samantha Yammine echoed that sentiment.

“What’s missing from the story is there are way more vaccinated people,” she said. “So the denominators are really different.”

Yammine said it’s crucial to remember that millions of people in Ontario are fully vaccinated, which means, “as more people get vaccinated, you may see more people test positive.”

Dr. Alon Vaisman, an infectious diseases and infection control physician, also pointed out what he described as “important nuance.”

Dr. Vaisman said we need to move away from using the province’s case count as the central denominator when this new daily data is released and instead, start comparing the breakdown of hospitalizations and ICU numbers to the number of vaccinated people in the province.

That way, he said, we can show just how effective vaccines are, rather than feel alarmed when vaccinated individuals do get COVID-19.

In reality, Vaisman said, the proportion is “remarkably small.”