The Delta curve ball: How worried should Canada be about the COVID variant?

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Five weeks ago, Rodney Russell gave a talk he titled, “Will vaccines end the pandemic?”

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Five weeks ago, the answer was yes, “because, when I looked at the data, the epidemiology in Israel, the U.K., the U.S., I said the countries that have vaccinated the most aggressively have seen the fastest declines in cases per day, and they were staying down,” said Russell, a professor of immunology and virology at Memorial University and editor-in-chief of the journal Viral Immunology.

Today, all three of those “three big vaccinators” are seeing an upturn in COVID driven by the Delta variant that first surfaced in India in October 2020. It’s now the globe’s most dominant strain, and an exquisitely contagious one.

The experience in other countries offers Canada a cautionary tale on vaccinations, especially second doses. Without “really, really high immunity,” Russell said, “there’s going to be a tonne of virus in the population.”

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Polls suggest 10 per cent of Canadians are immovably opposed to vaccines, while 10 per cent are hesitant, or simply not in a rush. “But this virus spreads so fast, and is so contagious that, if 20 per cent of the population is not vaccinated, that will be more than enough to keep this thing going, and give it the opportunity to keep mutating,” Russell said.

Some vaccinated people have also been infected, though breakthrough infections are not surprising and, according to experts, are not occurring at an alarming rate. The vaccines don’t offer 100 per cent protection against SARS-CoV-2 and not everyone inoculated mounts a strong response. But COVID is generally less severe in the doubly vaccinated and is not killing people at the rate it once was. “In this vaccinated group, we’re seeing much milder disease. And this is going to be very much the norm for the new few months, or possibly years,” King’s College London epidemiologist Tim Spector, head of a massive COVID symptom study, said in a video update this week.

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Still, confirmed cases per million in Britain, where two-thirds of adults have received two doses of a vaccine, are “pretty high up compared to those around us,” Spector said. With the July 19 so-called “Freedom Day” — and the lifting of virtually all public health restrictions — mere days away, the U.K.’s rolling seven-day average this week was more than four times higher than it was a month ago. Britain reported 48,553 new cases on Thursday, while the number of people in hospital rose 42.8 per cent in a week, Bloomberg reports.

Spain, Portugal, Greece and the Netherlands are all experiencing rebounds for reasons that, Spector said, can be attributed to “the very special properties of the Delta virus” — it has an uncanny ability to glob on to human cells more tightly — “and a slight relaxation of restrictions in most countries.”

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Israel has reinstated its indoor mask rule. In the U.S., confirmed COVID cases are up 70 per cent over the previous weeks and deaths 26 per cent, with outbreaks in parts of the country with meager vaccine uptake. The U.S. seven-day average now more than 26,000 daily cases, more than double its June low of around 11,000 cases. According to public health experts, 99 per cent of Americans now hospitalized with COVID haven’t been vaccinated.

In severe cases, COVID from Delta doesn’t look much different from severe illness caused by older iterations of the virus. People can end up on life support, with multiple organs failing. “What is very different about those patients is that, for the most part, they have been young people, and almost all of them, in our experience in Saskatchewan, have been unvaccinated folks,” said Dr. Hassan Masri, a critical care and ICU specialist in Saskatoon. “We have not seen a single patient land in the ICU who is double-dose vaccinated.”

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The young and not inoculated are largely driving Delta’s spread in other parts of the globe and, in Canada, young people seem less eager to be vaccinated. Also concerning: the rate of increase for the first dose has slowed and less than half of Canadians are fully vaccinated. Masri predicts that by the end of September or early October, as people move back inside and schools and campuses reopen, Canada will see a small but consistent increase in spread, as public health measures are, appropriately so, relaxed.

An initially silent, asymptomatic spread will likely continue for four to eight weeks, he said, followed by a not-so-silent spread, “and we will have the nucleus of the fourth wave. I think we do need to understand that’s going to happen, we need to make sure that we continue to be cautious.”

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An uptick in cases doesn’t necessarily translate into a proportionate increase in hospitalizations or deaths, he said. But the proportion of Canadians with only one dose — or none — remains high.

“This fall is not a reason to double down on public health measures — certainly, I think most relaxations of public health measures are appropriate,” Masri said. “This is more of a warning to double down on the efforts to vaccinate.” We must go harder, he said.

Spector, of King’s College, believes it’s also important people recognize that the symptoms of COVID are different in breakthrough infections. COVID after vaccination very much resembles a bad cold — runny nose, headaches, sneezing, and sore throat, perhaps a possible loss of smell. “But don’t wait for coughs and fever,” he said in his video. “They may never happen. Assume you’ve got COVID, get a test.”

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Delta is hyper-contagious, and the unvaccinated are clearly more at risk of getting infected and getting sick. “This is becoming a pandemic of the unvaccinated,” U.S. Centers for Disease Control and Prevention Director Dr. Rochelle Walensky said during a press briefing this week. Recent research from France bolsters the case for a second dose: blood samples from people given one dose of Pfizer or AstraZeneca “barely inhibited” Delta. Two doses generated a neutralizing response in 95 per cent of people.

One of the most pragmatic questions now, said Russell of Memorial, is, “What does it mean, on an individual basis, if you’ve been vaccinated and we’ve got Delta around?”

Even if infected, even if the antibody response is low, “you still shouldn’t get as sick as if you had no vaccine, so there’s no doubt it’s better to get vaccinated,” he said.

“You might not have a high viral load in your nose, and you might not spread … but nobody knows their nasal viral load. Which is why I’m telling people, ‘Wear your mask for another few months, until we see what happens here.’”

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