We asked Matthew Miller, associate professor, biochemistry and biomedical sciences, to answer questions from our community about COVID-19, pandemics, and infectious diseases in general. This Q and A was originally posted as an “Ask Me Anything” series on McMaster’s Instagram account.

Q: IS IT LIKELY THAT A SECOND WAVE OF COVID-19 WILL HIT CANADA, AND WILL IT BE WORSE THAN THE FIRST?
I think most experts will agree that it’s almost inevitable that we will see a second wave of the COVID-19 pandemic. The question of course is how bad will the second wave be.

Certainly there’s a lot more public awareness now around the infection control measures that can help us prevent the spread of this virus. Things like physical distancing and masking are now concepts that the public understands well and that places in the community have strict policies for. If these protective measures are well adhered to I think there’s good hope that the second wave will be less pronounced than the first although perhaps extended in terms of the duration of time that we see this uptick in cases.

However, if we don’t remain vigilant and if we aren’t careful, especially in high-density city settings like university towns with students coming back to school, it’s certainly possible that the second wave could be more severe than the first. So this is something that’s going to require a lot of public vigilance as we move into the fall and winter months, turn heat on and are forced indoors in closer proximity, which favours transmission of the virus. 

Q: HOW HAS COVID-19 AFFECTED ACADEMIC RESEARCH?
COVID-19 has certainly posed significant challenges for those of us engaged in academic research. During the early phases of the pandemic many institutions were forced to undertake temporary research shutdowns in order to decrease the density of individuals on campus in order to try and prevent the spread of the virus.

However, there’s also been some really encouraging things to come out of the COVID-19 pandemic. Individuals from across all disciplines of academic research rapidly repositioned their research programs and expertise in order to try and provide the urgent solution that this pandemic necessitated.

We’ve also seen really unprecedented cooperation between scientists not only across disciplines but across different countries in working together to try and rapidly and openly solve a lot of the major problems that this pandemic has presented us with.

Q: WILL THERE COME A TIME WHEN WE CAN AGAIN GO OUT WITHOUT A MASK?
Absolutely! Like all things, this pandemic will eventually come to an end. I anticipate that the masking mandate will end sometime after a COVID-19 vaccine has been distributed and widely uptaken because that’s what will drive high levels of population immunity.

I do want to point out though that the normalization of donning masks may actually be a really good thing because masks can help prevent the transmission and spread of lots of other respiratory viruses including things like influenza. And so going forward it may be worth giving some thought to wearing masks in particular high-risk settings, at certain very high-risk times of the year to help us decrease the burden of some other infectious diseases that plague us season after season. 

Q: WHAT DO YOU KNOW ABOUT A COVID-19 VACCINE BEING DEVELOPED
In reality there are actually many COVID-19 vaccines being developed right now in parallel, including some right here at McMaster.

The most advanced of these vaccines are now in phase 3 clinical trials. Data from early phase clinical trials that has measured the immune responses that these vaccines are able to induce have been very promising. I think it’s extremely likely that we will see several different COVID-19 vaccines receive approval, probably in early 2021. However, there will still be a significant time lag between when these vaccines are approved and when they are manufactured and distributed in great enough capacity to be available to the general public.

So, while I think that it is extremely likely that we’ll see several different COVID-19 vaccines approved, they won’t, in all likelihood, be available for the general public for quite some time.

Q: WHAT IS THE PROCESS FOR A VACCINE TO BE APPROVED FOR DISTRIBUTION?
Vaccine development starts in pre-clinical models where researchers typically test the safety, immunogenicity, and efficacy of a vaccine in a small animal system. If those tests go well the vaccine may be approved to move into human clinical trials.

Phase one and phase two clinical trials are typically small (tens to hundreds of individuals), and in these phases of clinical trials the safety and immunogenicity of the vaccine is evaluated.

If those phases go well and have promising results a vaccine can advance to phase three clinical trials. These are the largest phases of the trials and typically enroll tens of thousands of individuals. In phase three safety is tested most robustly because the population is so large and in addition, very importantly, phase three is where we measure the effectiveness or efficacy of a vaccine.

If the vaccine is deemed to be both safe and effective at the conclusion of phase three clinical trials then it can receive approval for distribution.

Q: WHAT MAKES ONE VACCINE MORE EFFECTIVE THAN ANOTHER?
Vaccine effectiveness is largely determined by the efficiency with which the vaccine can stimulate a protective immune response in the vaccinated individual. Vaccines typically aren’t one-size-fits-all, different types of vaccines work better in different populations.

For example, a vaccine that’s highly effective in a child may be different from a vaccine that’s highly effective in elderly adults because of the way in which they need to stimulate the immune system in those different populations. 

Q: IN YOUR OPINION, HOW HAS THE VACCINE DEVELOPMENT LANDSCAPE CHANGED?
I think one of the most interesting and promising ways in which the vaccine development landscape has changed is that many of the coronavirus vaccines currently under development is really novel and innovative vaccine platforms that haven’t yet seen widespread use.

I’m hopeful that if one of these vaccines becomes approved it will ease the development and approval timeline for subsequent vaccines using these platforms because these platforms really hold a lot of promise in terms of allowing us to make better vaccines for a lot of different infectious diseases. 

Q: IS SARS-CoV-2 A VIRUS THAT WILL EVENTUALLY BE ELIMINATED?
It’s not yet clear what the fate of SARS-CoV-2 will be at the conclusion of this pandemic. However, other coronaviruses that have jumped from animals to humans have gone on to establish themselves as seasonal infections.

Whether or not SARS-CoV-2 can be eliminated will depend both on the strength and duration of immunity that humans are able to achieve after being infected or vaccinated with a SARS-CoV-2 vaccine as well as the rate at which the virus is able to mutate to escape pre-existing immunity.

Q: DOES GETTING THE FLU MAKE YOU MORE SUSCEPTIBLE TO COVID-19?
It’s not yet clear what the influence of influenza is on one’s susceptibility to getting COVID-19. However, it’s intuitive that two severe respiratory inflections back-to-back could be very problematic.

Therefore it’s extremely important this year that individuals ensure that they protect themselves from the flu by getting vaccinated. This will decrease the likelihood that they contract both diseases over a short period of time which could have very severe consequences.

Q: IS THERE DATA REGARDING WHETHER THE FLU SHOT MIGHT MAKE YOU MORE SUSCEPTIBLE TO COVID-19?
No, there isn’t. Quite to the contrary, it’s probably more important this season than ever to get your flu shot.

The reason for that is because as flu season begins to emerge in the midst of this pandemic, increased numbers of flu infections have the possibility of putting increased strains on our hospital systems, which will already be busy dealing with COVID patients. So protecting yourself against the flu is really important to ensure that our hospital capacities remain high.

In Australia, whose flu season just ended, they had the highest ever rates of vaccine uptake this year and that in combination with the physical distancing and masking measures put in place to control COVID-19 actually resulted in them having their mildest flu season in recent history.

There’s good reason to expect that if people go out and get their flu shot this year and are careful about COVID-19 infection control measures that we might actually end up having a very light flu season this year. 

Q: HOW CAN SOMEONE DIFFERENTIATE BETWEEN THE FLU AND COVID-19?
For the average person it’s likely very hard to distinguish between COVID-19 and influenza virus infections. However, one of the more common symptoms of COVID-19 infections is temporary loss of taste and smell. This seems to be much more prevalent with COVID-19 than it is with influenza and maybe one of the best ways to distinguish between the two. 

Q: WHAT CAUSES THIS LOSS OF TASTE AND SMELL?
The temporary loss of taste and smell reported by some COVID-19 patients is due to interference with olfactory nerves. These are the nerves that control our sense of taste and smell.

It’s not yet entirely clear exactly what the virus is doing to cause these nerves to malfunction. Some reports have suggested that the virus is able to infect the cells that support these nerves and this leads to temporary malfunctioning. It’s also possible that inflammation induced by the infection interferes with these nerves on a temporary basis and results in loss of taste and smell during infection. 

Q: HOW IS COVID-19 SPREAD BETWEEN CHILDREN?
The way in which COVID-19 spreads between children is almost surely the same as the way it spreads between adults; mainly by respiratory droplets and close contact. The difference with children is that they seem to be less efficient spreaders of the virus and although the reasons for this are not yet entirely clear it’s very likely that this is at least in part due to the fact that children seem to be less symptomatic during COVID-19 infections.

Symptoms that many adults experience like coughing and sneezing facilitates spread of the virus and so the absence of these symptoms in many infected children may be one of the reasons why they tend to spread viruses less efficiently both amongst each other as well as to other individuals in the community.