News about a potential coronavirus vaccine has, predictably, prompted excitement from a lockdown-weary world.
But experts say: Not so fast.
“It’s completely understandable to have enthusiasm, but this is not going to be instantaneous,” said Alyson Kelvin, a Dalhousie University researcher who specializes in emerging diseases.
Memes circulating online fall under the same hopeful theme — that the vaccine will immediately set us free. There are videos of people and politicians dancing “after taking three shots of the Pfizer vaccine and a gin and tonic at the club,” photos of kids licking a handrail with the caption “me the very second I’ve taken my vaccine,” and tweets like the ones below.
But there’s a thread of steps involved in the process, Kelvin said, including ones that follow getting a needle in your arm.
“I’m glad people are excited about the vaccine and excited to get it,” Kelvin said. “We’ll get there, but it’s important to be balanced.”
Time and demand
The distribution of any — or multiple — vaccines will take time, said Kelvin, but so will dispensing it to people.
Prioritization strategies will steer who gets the shots first, and demand will outweigh supply for many months after the first batch is doled out.
Those barriers are enough to demonstrate that a return, outright, to pre-pandemic life isn’t within reach quite yet, said Kelvin.
She pointed to the Swiss Cheese Model, which uses slices of cheese to visualize how interventions work together. Each intervention is depicted as an imperfect barrier to virus transmission by the holes in each cheese slice. When multiple effective, but imperfect, slices are stacked together, some holes are covered and virus transmission is decreased.
It’s unlikely that the holes in every slice will line up allowing virus to slip through the layers, but it still might get through a couple of holes.
“The vaccine will be just one layer and there will still be holes in that layer,” she said.
“We’ll still have to keep the other layers of protective measures, like wearing masks and physical distancing, but there’s more of a hope we’ll be able to relax others, like opening stores again.”
Isaac Bogoch, an infectious disease specialist based out of Toronto General Hospital, agrees. He said Canada will still reap rewards from the prioritization stage of vaccinations, “even with only a fraction of the vaccinations required to achieve herd immunity completed.”
“We’re not going to see an outright return to normalcy, but we’ll start to slide towards it as these programs roll out, and more so as they become widespread.”
Vaccination stages
Despite unprecedented effectiveness results from several vaccine candidates, a dose (or two) of an approved vaccine won’t be a panacea either, experts say.
In other words, it won’t be an in-and-out situation at your doctor’s office.
As summed up by comedian Jesse Case on Twitter: “Omg what’s the first thing you’re gonna do when YOU get the vaccine shot?? You’re gonna go back home, wait a month, get your second shot, go back home, wait 14 days for antibodies, then keep wearing a mask and social distancing until community transmission reduction. That’s what.”
Kelvin agrees, but notes there may be some variation based on each candidate.
Both the Pfizer and Moderna vaccines will require two doses. Pfizer’s booster shot will be given three weeks after the first one, while Moderna’s is spaced four weeks later. AstraZeneca-Oxford also requires two doses, but its trials have found it was far more effective when the first dose was half the amount of the typical dose. The second dose was given a month later.
Then there are the antibodies. Clinical trials have evaluated vaccinated people seven to 14 days after their second dose to identify the presence of antibodies.
“Fourteen days would be a good, conservative, solid window when we expect to have any immunity gained from the vaccine,” said Kelvin. “You would be fully protected 14 days after the boost shot.”
From the time of the first dose to the second dose, to an approximate 14-day antibody waiting period, it may be a six-week process.
And there are still holes in the solution, said Kelvin.
“These trials are measuring the reduction or absence of disease, not reduction of infection,” she said. “What we don’t know is if you are still able to contract the virus and if you are still able to spread it after getting the vaccine.”
The majority of people might have great responses and be protected from COVID-19, but others — particularly older people — might not.
“Just because an older person was vaccinated doesn’t mean they will have the same response as a younger person and be as protected,” she said.
Bogoch isn’t as concerned.
“If this turned COVID-19 from a severe illness into the sniffles, it’s still a huge success and we won’t be paralyzed the way we are,” he said.
“Even if people with reduced severity of illness can transmit the infection to others, if vulnerable populations have received this vaccine, you’re still miles ahead. You’re not going to have lockdowns.”
How free will we be?
Bogoch believes there might be a nugget of truth to some of the post-vaccination memes floating around on social media.
The meme-makers — presumably young people — might actually be the closest to a semblance of normalcy once their turn for a vaccine arrives, mainly because they’d be mostly last in line.
“By the time the vaccine program rolls out to 20 and 30-year-olds, we’re doing something right,” he said.
The vaccination of vulnerable populations alone will not only reduce the strain and burden on health-care systems but make reopening parts of the economy more feasible, the experts agree.
It also brings us closer to herd immunity, they said, which requires around 60-70 per cent of the population to be vaccinated in order to develop.
“But we will still see significant benefits well before that,” Bogoch said.
It won’t be as simple as sticking out your arm, getting the shot and heading to a dinner party or revisiting a sports arena, experts agree.
It will be up to all levels of government to educate Canadians about what behaviour is expected of them pre-vaccine and post-vaccine, Bogoch added.
But “there will be some relief,” said Kelvin.
“Hold onto that enthusiasm. Just take it a bit slower and know it’s not going to happen overnight.”
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