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No vaccine for SARS, so why do we need one now? Your COVID-19 questions answered

We're answering your questions about the pandemic. Send yours to COVID@cbc.ca and we’ll answer as many as we can. We’ll publish a selection of answers every weekday online, and also put some questions to the experts during The National and on CBC News Network.

From vaccines to vulnerable populations, here's what you’re asking us today

Scientists were able to contain SARS by isolating cases, but the novel coronavirus is too contagious to use the same methods. (Dado Ruvic/Reuters)

We're answering your questions about the pandemic. Send yours to COVID@cbc.ca and we'll answer as many as we can. We'll publish a selection of answers every weekday online, and also put some questions to the experts during The National and on CBC News Network. 

Why do we need a vaccine for COVID-19 when we didn't have one for SARS? 

As people around the world await a vaccine, some Canadians have been wondering how we were able to get rid of SARS without one, including Jennifer C.

We took this question to Dr. Matthew Miller, associate professor in the Michael G. DeGroote Institute for Infectious Disease Research at McMaster University in Hamilton.

He explains that SARS wasn't as contagious as the novel coronavirus and that isolating cases back then was effective enough to contain the virus from spreading to the same degree.

"We were able to essentially identify and isolate individuals who were sick with SARS and that alone was enough to prevent it from spreading because it wasn't good at spreading to begin with," said Miller, who is also an expert in viral pandemics and vaccines. 

But this coronavirus has behaved differently.

"It's actually very difficult for an animal virus to infect humans," Miller explains, "but this coronavirus has been unusually successful."

It's the reason behind the pandemic, and it's also the reason the same isolation measures used in SARS aren't as effective. 

"Lots of people seem to transmit the virus before they have symptoms," Miller said, which explains why isolation measures can be hard if someone doesn't realize they are sick. "If they don't have symptoms, you can't know that they're infected and isolate them."

top U.S. expert says an experimental vaccine could be ready in 12-18 months, but some provinces are already loosening their stay-at-home restrictions. 

Do seniors and vulnerable populations need to stay inside until there is a vaccine?

Some provinces have started to loosen restrictions on stay-at-home orders. But what does that mean for seniors and vulnerable populations? R. Adelman is wondering how they should approach the reopenings. 

"It's all about balancing the risks," said Dr. Michael Curry, a University of B.C. professor and emergency room doctor at Delta Hospital.

While mitigating that exposure for vulnerable populations is important, Curry says people are still going to need to go about their daily activities, like grocery runs, and that will come at a social cost.

"There is going to be a need for some degree of social interaction," he said, "so the older and sicker you are, the more vulnerable you are, then probably the more precautions you want to take."

What do those precautions look like?

Curry suggests limiting the amount of times you go outside for now and practising good hygiene (physically distancing, washing your hands frequently and avoid touching your face) to "keep the risk down to a low level."

If you have a serious underlying medical issue, you may want to consult your health-care provider to help you make a decision about what's best for you. 

Doctors answer your questions about COVID-19, including whether people over the age of 70 should self-isolate at home until there is a treatment or vaccine. 4:17

Is the virus airborne? 

Steve W. wants to know whether there's any truth to reports the virus is airborne. For the answer we turned to the experts at Second Opinion who tackled this topic in the latest edition of their CBC News health newsletter.

According to the World Health Organization (WHO), the coronavirus spreads primarily through tiny droplets expelled when a person infected with it sneezes, coughs, exhales or spits while talking. They can infect another person who:

  • Comes into contact with those droplets through their eyes, nose or mouth (droplet transmission).
  • Touches objects or surfaces on which droplets have landed and then touches their eyes, nose or mouth (contact transmission).

The WHO says it's important to stay "more than one metre away" from a person who is sick. But the Public Health Agency of Canada (PHAC) recommends at least two metres or two arms' lengths away, not just from people who are sick but from anyone you don't live with.

A pair of recent studies raised the notion of airborne transmission, but Mark Loeb, a professor at McMaster who specializes in infectious disease research, cautions against putting too much stock in them. 

Researchers found traces of RNA from the coronavirus in washrooms and some high-traffic areas in hospitals in Wuhan, China, and in Nebraska, and suggested it got into those areas through the air, though there was no evidence the particles were still infectious. 

Loeb said that's just a "signal" that part of the virus was there. 

"Does it mean that COVID-19 is spreading from person to person through aerosols? I would say definitively not," Loeb said. 

If the virus were airborne, we'd know by now, said Dr. Allison McGeer, an infectious disease specialist with Sinai Health in Toronto who is leading a national research team studying how COVID-19 is transmitted.

"The reason we know that is because all around the world we have hundreds of health-care workers who are taking care of patients wearing regular masks," she said. "If this were airborne — if this were usually in those small [aerosol] particles — all those health-care workers would be getting sick."

The fact that they're not is a contrast to what would happen if the virus remained infectious in the air for hours even after an infected person left the room — which is part of what makes diseases like measles so contagious.

Can the coronavirus lurk under rings, watches and jewelry?

Dana N. wants to know if she needs to worry about the virus lurking under her ring or watch. Experts agree that washing your hands correctly is the best way to stop the spread of infections, and that means washing frequently and thoroughly, with soap and water for at least 20 seconds.

Effective hand hygiene can be prevented by the presence of bracelets and wrist watches, according to PHAC. "Skin underneath rings has been reported to be more heavily colonized than comparable areas of skin on fingers without rings," according to this hand hygiene guide posted on the PHAC website.

We asked cardiac surgeon Dr. Samantha Hill how she washes her hands, and she agreed that jewelry can create "a little pool where the viruses and the bacteria can [hang out.]"

Watch Hill's demonstration on how to wash your hands like a surgeon.

We're also answering your questions every night on The National. Last night, an infectious diseases specialist was asked if there will be a second lockdown. Watch below:

An infectious disease specialist answers your questions about the COVID-19 pandemic including whether there will be a second lockdown. 2:37

Monday we answered questions about reopening schools and attending summer camp. 

Keep your questions coming by emailing us at COVID@cbc.ca.

With files from Cheryl Brown

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