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Dr. Srinivas Murthy is a clinical associate professor in the UBC department of pediatrics, an infectious disease specialist and investigator at BC Children’s Hospital, and Health Research Foundation of Innovative Medicines Canada Chair in Pandemic Preparedness Research. As part of a vaccine education project to reach newcomer and immigrant communities in partnership with Here Magazine, Masjid Al-Iman and the Victoria Foundation, Dr. Murthy spoke with Managing Editor Fiona Bramble about COVID-19 and COVID-19 vaccines in late April 2021.

I’m very sorry to hear about the recent loss [due to COVID-19] of such a young patient at BC Children’s Hospital. What kind of impact has that had on you? Any death is hard, and especially the death of a child is hard in general. It speaks to how nasty this virus is and how much we need to do to make everyone safe.

Do you think it’s had an impact on the wider community in terms of their behaviour? I’ve gotten a lot of questions since it was announced, both from my friends and family, and from the media. Yes, it has affected people. It was a young patient. We always presumed that this is a disease affecting older people. Not that that should change how we perceive the disease. However, it definitely hits us in a different way when we start to think that children are susceptible. How it affects people’s behaviour is difficult to say. Individual motivation is a tricky thing to predict and understand. We all have our own drivers.

What led you to this field of work? I have always been interested in emerging infections—things that come out of nowhere, and trying to figure out how to learn about them quickly, especially how to manage major outbreaks better. That’s always been my “thing,” both research and operational: Ebola, hemorrhagic fevers, and diphtheria—all these diseases that pop up in different countries. I would go with the WHO (World Health Organization) or MSF (Médecins Sans Frontières) so I could do research or clinically manage patients. 

More generally in your COVID-related work, what kind of questions are people struggling with? Usually, it’s a “should I in this X, Y, Z situation get this vaccine?”  A lot of “Can I do this? (which public health seems like it doesn’t want me to do) But can I do it anyway?” I get that question quite frequently. Like, “Can I go camping?” or “Can I go to the mall?” or have a birthday party or whatever. Day-to-day stuff, those are the common questions that emerge that relate to the public more broadly. Obviously, clinical questions and disease-based questions are part of my workday, but when I’m talking to friends or family what have you, it’s pretty much: “can I do this?” and “vaccine this?”

Many newcomers to Canada still rely on medical advice from their family physicians back in their countries of origin, and sometimes that advice challenges or contradicts medical or public health guidance here in Canada. How do you navigate this? Obviously it’s complex. Different people have different perspectives, so it’s nice to pick up a phone and have a conversation to assuage any concerns or questions that come up. I never want to say we know best in Canada and they don’t know anything over there, wherever there is, because that would be ridiculous. But it’s important to work through the process and find out where people are coming from.

It is being repeated that “any vaccine is better than no vaccine.” Is that absolutely true, always and in every case? Yes, it is, but everything depends on something. If there is disease transmission in your community, then any vaccine is better than no vaccine. If there are very very low rates of transmission, like, for example, in New Zealand right now, they are not in any hurry to vaccinate. They are taking their time. They have only Pfizer and are doing that across their population at a leisurely pace. They’re not saying any vaccine is better than no vaccine. They are saying we have one vaccine and will we vaccinate over a period of six months. We are nowhere near that [low rate of transmission]. We in BC are saying that, based on disease transmission risk, any vaccine is better than no vaccine. Newfoundland and PEI could perhaps consider it from a New Zealand perspective as well. They have that flexibility and opportunity. We don’t.

Our community has many specific questions about vaccines, such as: are the vaccines safe for pregnant women and their unborn children, as well as for nursing mothers? As far as we know—and we have had 10s of 1000s of people vaccinated who are pregnant—they have no higher rate of adverse effects. We are saying, most societies are saying, even though Health Canada and the regulators can’t say it formally yet, it is an individual-risk decision. My recommendation is that it is safer to get the vaccine than not. 

Does a vaccinated mother transfer COVID-19 immunity to her nursing infant? We’ve seen a few studies looking at that and it actually seems that the infant does have antibodies. Remember also that some types of antibodies pass from [a pregnant] mother, through the placenta, to the baby. If mom has enough antibodies, they will protect the baby. Not that babies are at high risk of getting the disease, but it’s nice to get that protection.

 And that is also true if the mother had had COVID, correct? Yes, but it’s a different risk profile. Pregnant women with COVID-19 tend to do poorly. On the balance of risk, getting the vaccine is much much better than getting the disease if you want your neonates to be immune.

Babies are at low risk. Is that connected to why there doesn’t seem to be any urgency to ensure the current vaccines are safe for youth under 18? There will be vaccines available for children, young children. It’s just not a priority for anybody right now; everyone is focused on making sure the people most vulnerable from getting the disease and getting severe disease are protected. We won’t be able to get to “herd immunity” until we vaccinate children, but before we get there, we still have to protect people and prioritizing adults is totally rational.

That is because younger people’s outcomes are better when they contract COVID? Yes, there are very low rates of severe disease [in younger people].

 What vaccines are available in BC right now? Pfizer, Moderna, and AstraZeneca. Johnson & Johnson has not been rolled out here yet, but should be here shortly.

What are the priority populations for vaccinations? They include age-based, clinically-extremely vulnerable, and Indigenous populations, as well as essential workers. If you are vulnerable for a bad outcome, you should be vaccinated. If you are vulnerable for getting the disease because you can’t appropriately protect yourself because you have to work to keep food on the table, then you should be vaccinated.

Are essential workers being vaccinated through programs at their workplace? Yes, many are being vaccinated through the workplace.

Teachers are considered essential workers? Yes.

What percentage of the population will need to get vaccinated to achieve “herd” or “population” immunity from COVID-19? Our definitions of what we need for “herd immunity” vary depending on what study you look at, how you define the herd and so on. It could range anywhere from 50-95 percent.

 What do you mean by “define the herd?” What is the population? Where are we drawing our lines? Is there a herd in the United States? A herd in Canada? A herd in British Columbia? In reality, you need a big herd. For example, we have measles “herd immunity” but we still have outbreaks and cases because people travel to places that do not have herd immunity. Vulnerable people travel back and forth and there will be outbreaks and problems. Saying that we have herd immunity in British Columbia isn’t particularly useful. 

And we don’t know yet what that “herd immunity” rate is for COVID-19? There is a range of possibilities for what proportion of the population needs to be immune for it to be protective for everybody, and it depends on a huge host of things.

Does a single vaccine dose prevent transmission of COVID-19? Primary studies did not look for whether the vaccine prevented transmission. They showed that the vaccine prevented disease in the individual. Every vaccine has prevented transmission in that if you have less incidence of disease you can plausibly think that you will have less transmission along with it. Since those initial studies of these vaccines, we’ve gotten some good studies that show that onward spread is slowed by people who are vaccinated. So I feel very confident that the vaccines likely do slow transmission. Do we know it proof-positive? No, we don’t know lots of things proof-positive. If it prevents disease after a single dose, then it should prevent transmission after a single dose. The amount of protection on spread we can’t say with a number, but we have to presume that it is there.

AstraZeneca was pulled from the vaccine rollout, and then reintroduced for certain age groups. Obviously, this created some confusion and mistrust of public health messaging. Given that the adverse outcomes are so rare and mainly affect women within a certain age group, would it not make sense to have a gender-based policy? It’s a tricky risk communication process as to how we say who is at risk and who is not at risk. It seems—and we’ve accumulated a ton of data so far—that you are right, that people of a certain age tend to be at higher risk. It’s still an exceptionally low risk in that population that we don’t want to say it’s dangerous for those people and it’s safe for these people because it’s safe for those people as well. It’s a good vaccine. It has a small rate of adverse events following it, which are serious, and something we need to pay attention to and have a conversation about how we balance risks and benefits. However, on the balance of risks and benefits right now, given our situation, the benefits hugely outweigh the risks. 

You understand that different messaging about the safety of some of the vaccines is confusing to the public? I get asked that a lot. I think from a trust perspective and the hesitant folks perspective, in the long run, it’s actually going to be better that we did it this way. That we paused, the country paused, looked at the data carefully, looked at the accumulating data from around the world, and shared information. Then came up with a pretty confident number of events per million vaccinated people and said: ‘this is the risk; it’s a very low risk. This is the problem.’ and then balancing those risks to individuals. I think if we knew those things were happening—and the public knows—and we did nothing about it, then I think the outcry after a death or two in Canada directly related to the vaccine would be a big problem. These are all unknowns at this point and I’m making my best guesses how to communicate to people and it’s hard. 

Do you have any concerns about people with auto-immune conditions? No, I don’t.The rates of clots are not higher in those with auto-immune conditions than those without auto-immune conditions.

Do you predict that once the vaccine supply is stabilized and we move into a post-pandemic state, that this will become a booster shot scenario with this particular virus? It’s likely. There are all sorts of variants that are emerging, so whether we’ll need a boost for the main disease, or whether we need “upping,” so to speak, for different variants that have emerged and become the dominant strains around the world is difficult to say. It’s an unknown. The Pfizer-Modernas of the world are banking on the fact that there will be re-vaccinations happening. But we don’t know exactly what they’ll be for and why we’ll do them or how often we’ll do them, but I think it’s a high degree of probability that’s going to happen. 

If we don’t vaccinate youth, around 15% of the population, and assuming an additional hesitant 10% are not vaccinated, that’s only 75% of the population vaccinated. Do you see that as a problem? Of course, yes. Every person who doesn’t get vaccinated is a problem, and it is worth a conversation to try to figure out why. It’s well worth the time and effort.

You mention that youth will be vaccinated eventually, they are just not a priority right now. Do you think youth will be vaccinated by September? I look at the world, and I think who needs a vaccine more and I can’t say the youth of British Columbia should be high on that list. 

Does your second dose of vaccine need to be from the same manufacturer or just be the same type of vaccine? For now, we are saying same type, same manufacturer. That may change. Different places are doing different things. There might be a possibility of getting a second dose of a different vaccine as data emerges. Different places have been trying that. There’s no reason to think that it shouldn’t work.

Are there risks in delaying the second dose beyond the recommended timeline? I think we don’t know exactly what the risks are with that—like, does our immunity wane and we’ll not be protected for a period of time or not have as robust a protection? But in the balance of things, more people getting vaccinated means more people get protected and that is in my mind an easy trade-off to make.

Both are adenovirus vector vaccines, so why is the Johnson & Johnson a single dose and the AstraZeneca not? It’s the way they studied the vaccine mostly. One of them studied it to be a single dose and one of them studied it to be a 2-dose. They are similar vaccines but slightly different and it’s a matter of how they built the immunity system within it. Once Johnson & Johnson lands, it’s going to be great.

Are there any other promising vaccines under review right now? They are all promising and exciting to see. Pfizer, Moderna, AstraZeneca, and Johnson & Johnson will be the backbone of our program here, but Novavax is probably going to roll out at some point in the near future as well, in Canada and elsewhere. They’re all great. I’m excited by the Cuban vaccine. They’ve explicitly designed it to be made for export and made with open access, so anyone can make it. They’re designing it for the developing world specifically, so I think that’s a cool way of getting their product out there. 

Side effects post-vaccinations seem varied. Some people are down with aches and fever for a couple of days, others completely normal. People who have had the same vaccine, but totally different after effects. Can this be explained? Why would one person have a stronger reaction than another? We have data from other vaccinations that show a fever day-one post-vaccine or more symptoms you have, you might have a slightly higher antibody level than those who didn’t have that level of reaction. Does it mean anything for these COVID vaccines? No one knows. There are a thousand reasons why someone might have a stronger reaction than another: genetics, exposures in the past. Our immune system is a complex beast.

Are there any lesser known side effects or reactions post-vaccination that might surprise people? Fever and muscle aches are the main ones—general malaise for a day or two and then you get back up to speed. 

Generally, how soon post-vaccination are some people feeling these effects? 24-48 hours.

Are there any other symptoms post-vaccination, besides obviously, an anaphylactic reaction, that should trigger a visit to a doctor or Emergency? The AstraZeneca symptoms could happen within two or three weeks of getting vaccinated. It’s very rare. 1-3.2 out of a million. Basically, you might have a headache, you might feel swelling, you might feel short of breath. You should get checked out.

How do the current vaccines’ effectiveness against the prevailing variants in BC seem in terms of preventing infection and mitigating serious symptoms? Good. The vaccines work. Focussing on variants and things is important for us to control them and make sure we understand them, but the strategies against them are the same. Vaccinate and stay away from others who can give you the disease.

The curve in BC is finally trending down ever so slightly since the latest restrictions. Does that give you some confidence that we are going to get ahead, buy some time to get the vaccinations rolling out? I have a marginal amount of hope that our health system won’t collapse. I’m still fairly anxious about the next few weeks and how that is going to look in our health system.

Should transmission prevention best practices be changing at different stages of the vaccine process? For example, can I relax my “bubble” if I’ve been vaccinated? We are not at a place yet—only 25-35% of the population has had one dose—where we can comfortably say those people are protected enough to roam free and do whatever they want, even with each other, and that disease in the community is not going to affect them. We’re not there yet. 

And that’s because a. even though the vaccine likely slows or prevents transmission, there aren’t enough people who have had the vaccine yet, but also b. that you can still contract COVID even though you’ve been vaccinated? Yes, the vaccine is not perfect; you can still have the disease. It doesn’t mean that we will never be able to completely open up because that’s ridiculous. But what it does mean is that while we’re having widespread community transmission, having a small number of people be lax about things because they’ve gotten one vaccine and others can’t do those things is inequitable in a way, and also the actual protection you get from that first dose is unknown.

How would you explain the difference between aerosol spread and droplet spread to a layperson and whether it’s relevant to their lives actually? It’s relevant in that droplet spread means thinking about that six-foot radius that we always talk about, if something sprays out of my mouth, it lands on the ground. “Airborne” means the virus itself can sit in the air for a prolonged period. As it sits in the air, it can travel on the current and then go somewhere in the room, in the building through the ventilation system, and so on. When you think about building design and where you are safe or not safe, droplet vs. airborne makes a substantial difference. There is also a conversation about the size of the droplet and the particles itself and what kind of mask works best to protect you. I think all of these situations are important to consider. I’m not going to say it’s airborne and we all need to wear N95s in all circumstances and every building should have its ventilation upgraded but I will say we should upgrade our ventilation.

Is there any current COVID-related research out there right now that excites you? Obviously the vaccine research. It’s coming fast and furious. Seeing how effective these vaccines are pretty much consistently in pretty much every population is obviously super-exciting to see—how quickly and effectively they were scaled up and able to do the things they have. Obviously, there is a long, long way to go to get to the place we want to be, but we have the tools to get there. 

Are you seeing any race-based data in the vaccine research you are seeing? Yes, and no. Many studies don’t do a great job of collecting race-based data and different places in the world define things in different ways. So race-based data oftentimes becomes challenging to interpret across regions and populations. We’re seeing consistent non-differential effects of the vaccine. I think that bad outcomes are more related to underlying socioeconomic factors and racism.