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May 22, 2020 • read
What Canadians should know about a second wave of COVID-19
We’re not going back to normal anytime soon. It looks like we’re stuck with COVID-19 until we can develop a working vaccine (and get it out to everyone). No one wants to stay inside forever, but the possibility of a second wave of infections will probably keep many of us home for a while to come. So if opening up the economy means a higher risk of getting sick, is there anything we can do to prevent a surge in the number of cases? Here’s everything you need to know about what a second wave means and how we can do our best to prevent it.
What is a second wave?
Canadians have been successful at “flattening the curve” so far. But staying home was never about stamping out the virus. The goal was instead to spread out the number of people getting COVID-19 over a longer time frame to keep our hospitals from being overwhelmed. Once we start relaxing isolation measures, more people will likely get sick. More people out and about means more opportunities for COVID-19 to spread. But there’s a difference between a few additional cases and a large number of new infections. A second wave is when the number of infections begins increasing again after it’s been declining. While there’s no guarantee that every place will see a second wave, it’s also possible for countries (and smaller regions) to have successive waves — even three or more.
If all sick people stay home can we avoid a second wave?
Anyone with any symptoms of illness should already be self-isolating at home — even if you only have a headache or a sore throat. That’s because we know that some people with COVID-19 have very low-grade or atypical symptoms. But even if everyone with symptoms stays home, COVID-19 cases would likely continue to spread. That’s because you can have COVID-19 and be completely asymptomatic. That means that people can spread the virus without ever knowing they’re infected.
In theory, if we could lock down every person in the world for long enough, the virus would run out of hosts and disappear. But that’s not a realistic solution. People need to be able to buy food, healthcare workers need to be able to care for patients and the garbage needs to be picked up. Not to mention all the other essential workers who go out every day to keep our society running, or all the people who don’t have anywhere to properly self-isolate.
How can we prevent a second wave?
The best thing we can do as individuals is to continue to wash our hands frequently and to keep two metres away from others. In places where you can’t keep your distance, the second best thing you can do is to wear a mask, avoid touching your face, and wash your hands a lot. Because we don’t have an effective treatment or a vaccine for COVID-19 yet, physical distancing, contact tracing and testing for the disease are the most effective tools we have to prevent its spread and a major second wave of COVID-19 infections.
I think I’ve already had COVID-19, does that mean I’m immune?
While people who’ve had COVID-19 before may be immune from getting it again, there’s still a lot about immunity that we don’t know. For example, we don’t know if people who get COVID-19 but have no symptoms produce as many antibodies as people who get really sick from it. And if someone has enough antibodies that they are immune, we don’t know how long they’ll stay that way. In other words, we don’t know who will be immune or for how long.
Looking at illnesses caused by other coronaviruses (like SARS and MERS) doesn’t make the immunity picture any clearer. In one study, only about 55 percent of people who developed SARS still had antibodies to it after three years. Another study indicated that MERS left survivors immune for at least 18 months as long as they had had a severe case of pneumonia. But people with milder symptoms had more variability in their length of immunity. So we still have a lot to learn about individual immunity.
Can herd immunity stop a second wave of COVID-19 infections?
Herd immunity relies on enough people being immune to something that it can’t spread as effectively as it could in a population without immunity. This offers those who aren’t immune some indirect protection from infection. While it does look like people who’ve had COVID-19 may be immune from getting it again, there are a number of problems with the idea of herd immunity. For starters, we’ve successfully kept so many people from getting COVID-19 in Canada that we don’t have many people who are likely to be immune to it. This means that a huge number of Canadians still have to get sick with COVID-19 in order for us to get to the point of herd immunity. Not only would a number of people end up dying for us to achieve that, but it would most likely cause our hospitals to become overwhelmed.
Canadians have done a great job of beating COVID-19 back so far. But if restrictions lift too quickly, a second wave of COVID-19 infections could be worse than the first one. Until there is a vaccine, we will likely continue to see outbreaks of the novel coronavirus throughout the world. But how severe a second wave ends up being depends on the actions of each one of us.