why I’m getting the vaccine

This week has been an exciting one indeed, with the first shipments of the vaccine arriving in Canada and the unprecedented in the history of science and medicine materializing before our eyes: a vaccine developed in just 18 months.

But with all the hubbub and flurry of information being disseminated through every news channel, it is definitely overwhelming trying to sift through all the jargon and scientific literature while discerning which sources of information to trust or not trust.

My friends have asked me, “So, is this vaccine safe? How does it work? Wait, it uses nanoparticles?!”

This last question did in fact excite me, since nanotechnology is not always at the forefront of public health interventions, but now I finally have an excuse to talk a bit about my research on this blog 😄

Disclaimer: I am in no way an expert in vaccines, but what I offer is my opinion from sifting through various news and scientific articles of what we know, as well as what we don’t yet know and how I have decided to take the vaccine based on all of the above.

I’ll try to make this as simple and straightforward as I can, but also provide a bunch of resources at the end that I found especially helpful during this deep dive into the world of vaccines.

So with that disclaimer, welcome to the very first science communication article of this blog:

What we know

How the vaccines work

Humans have been doing vaccines for a long time. As a baby, you’re vaccinated against measles, tetanus, polio and a bunch of other things.

The vaccines we normally think of are dead or weak viruses, not strong enough to harm you but their presence in your body alerts your immune system (your body’s natural defence) to fight against these invaders. Your body gets good at recognizing these invaders and fighting them off, and it’s prepared the next time the real thing comes.

What is cool about the COVID vaccines is that though there are companies that going this tried-and-true method (the Chinese company, Sinovac, for example), a large majority of companies are taking different routes. In fact, the 3 front-runners: Pfizer/BioNTech, Moderna and Oxford/Astrazeneca don’t use dead and inactivated viruses at all.

The thinking is – instead of use the whole virus (which takes a while to grow, and of course, there is always the danger that we forget to inactivate it like what happened with the polio virus), why not find a part of the virus that could still train your immune system to recognize it?

Turns out, the COVID virus has a unique identifier on it surface called a spike protein. You know, those scary-looking spikes we’ve seen on many public health posters encouraging us to social distance. These spikes are what the virus uses to attack our cells .

Now, we could just inject the protein, but Moderna and Pfizer/BioNTech decided to use a piece of genetic code (messenger RNA) that tells a cell to produce the protein instead. The idea being that it’s much faster to produce mRNA than growing protein or whole viruses (weeks instead of months), and if we’re going to be churning out billions of vaccines for the whole world, we want speedy.

The problem is that if you just inject genetic code in your body, it would get chopped up by all the enzymes in your body, so that’s where nanotechnology comes in!

Both Moderna and Pfizer/BioNTech put the mRNA in a tiny delivery vehicle made of the same stuff of your cell membrane (lipids), so that when these nanoparticles bump into your cells, they fuse with your cell membrane and release its contents (the code) into your cell (see figure below).

Your cell then uses this code to produce the spike protein that your body needs to develop immunity to the virus. Pretty cool huh.

The Oxford/Astrazeneca vaccine operates based on the same concept but they use DNA instead (if you want to be nerdy, you could read up on the differences between DNA and mRNA :P) and instead of a lipid nanoparticle, they use a chimpanzee cold virus. But before you freak out, don’t worry, the cold virus only infects chimpanzees not humans, so we’re safe.

How do the different kinds of vaccines compare to each other?

I made a diagram below that compares the pros and cons of the various vaccine types. They all have various benefits, so we’re hoping that the more vaccines are approved, the better because they could be used for different purposes.

For example, the Oxford/Astrazeneca vaccine doesn’t need the -70 degree C freezers that the Pfizer/BioNTech one does (just a regular fridge), so scientists think it could be distributed to low-income countries where it’s hard to have a ton of low-temperature freezers.

Also the Oxford vaccine’s going to be a lot cheaper ($3-4/shot) compared to $20 for the Pfizer shot and $25 for Moderna.

How effective are these vaccines?

We also know that these 3 vaccines performed pretty marvellously in clinical trials. Well the Oxford results were a bit more puzzling, but we’ll talk about that in a bit.

The Pfizer vaccine  was tested on 43, 448 people with only 8 of vaccine recipients falling sick from COVID compared to 162 from those who didn’t get the vaccine. That gives you a 95% efficacy.

To give you some context, the flu vaccine is 50% effective (and we still take it), while the most effective vaccine ever developed is the measles vaccine with a 97% efficacy. So 95% is pretty crazy.

Now, the Oxford vaccine story is a bit more complicated. They reported a 70% efficacy but it turns out this number was combined from two different trials. One reported a 62% efficacy and the other that had a lower initial dose had a 90% efficacy.

Apparently, the lower initial dose was a mistake which led unexpectedly to an improvement, which is how many of the best discoveries are made in my opinion.

Scientists are still puzzled by why the lower dosing regimen worked better. And it’s okay to admit that we don’t know just yet.

You being updated real-time on this unfolding story is giving you an inside look into how the scientific process works and I think this will hopefully make for a more authentic and transparent relationship between the scientific community and the general public.

How was the vaccine developed in such record time?

I think we’re in a really cool era in science/research, where there is a huge push towards open science (making data available to the public so there is more accountability) and international collaboration.

This vaccine development is proof of what can happen when this trend in research collides with the willpower of powerful humans around the world who want to make this happen.

The open science part started with China releasing the viral genetic code so scientists all over the world could immediately start working and continues with pharmaceutical companies posting their clinical trial protocol publicly so other experts can review it.

But of course, as we know, money is often a major bottleneck in getting clinical trials running so the federal governments and the Gates Foundation injecting billions of dollars to push for the vaccine was a major factor in its “warp speed” development. This allowed trials to be run in parallel instead of one after another.

Then, there was the emergency use authorization by the FDA that allows use of an unapproved vaccine while trials are still ongoing as long as the vaccine meets certain criteria and no current alternatives exist.

The criteria in this case was an efficacy of at least 50% (the vaccine candidates far surpassed this baseline!) and safety data for at least 2 months after vaccination.

What we don’t know (yet)

But, Vivienne, you stop me in my excited rant, doesn’t this “warp speed” development also mean there is potential for mistakes and there is just so much we don’t know?

Sure, here are some major questions we still don’t have answers for yet:

We still don’t know if the vaccines can prevent transmission. As in, you could have the vaccine and not have any symptoms of the disease (which is what the clinical trials were monitoring for), but still be an asymptomatic carrier who could transmit the virus to someone who doesn’t have the vaccine.

We don’t know how long the immunity will last. It just has been too short of time to track long-term immunity. Because we lack this long-term data, we also don’t know if the virus could evolve to evade immunity or if there are long-term safety concerns.

Now the question of long-term safety concerns is a tricky one because say someone who got the vaccine develops a serious condition 10 years later, how would you know it was traced to the vaccine?

You would need enough (by this I mean statistically significant number) people in the population who got the vaccine to develop that condition compared to those who don’t have the vaccine.

But the ethical conundrum is this: how can you stop someone from getting the vaccine just so you can run a scientific experiment?

Even now, scientists are running into this question in their clinical trial where those in the placebo group are now requesting to have the vaccine (and I don’t blame them), but in this case, you can’t really monitor for long-term safety concerns.

We also don’t know a ton about how the vaccine works with different populations. We don’t have any data yet on children and pregnant women, which is why they’re going to be the last group to vaccinated.

But you see, it’s a bit of a chicken and egg problem, because you’re not going to know all this information until you actually start vaccinating people and let the scientists do their work.

Which leads me to my next point –

Why I will take the vaccine (as soon as I’m allowed to).

As you can probably tell by now, we’re all in the middle of a big, grand, world-wide science experiment.

We know enough – that the regulatory boards have deemed the vaccine safe and effective enough to be distributed across the world – and that is the only option we have of ending this pandemic.

Now, if we had all the time in the world, and thousands of people weren’t dying everyday because of COVID, the ideal would be to be running these long trials with tons of people to account for diverse populations and long-term effects.

The fact is: we just don’t have enough time and this is the best we have right now.

The scientists have worked long and hard hours in the lab (trust me, it’s hard work!) to produce this vaccine in crazy record time, but all the work is for nothing unless we actually take it.

“No matter how good of a vaccine we have, it’s only as good as it can be taken up. So if we don’t immunize enough of the population, COVID-19 … will be in the population long-term,” Dr. Cora Constantinescu, a pediatric infectious disease specialist with the University of Calgary says.

The thing is – for the vaccine to be truly effective, enough people need to be vaccinated for us to develop herd immunity.

What that number is, no one really knows, although Dr. Fauci estimates that it’s more than 2/3 of the population (about 75 – 85%).

Which is concerning, because surveys are showing the percentage of people willing to take the vaccine is still trailing behind that number (58% exactly in the U.S. according to a Gallup poll from Oct/Nov).

This means for this to work, we need to be willing to take the vaccine when it comes out (as well as tell your friends/family, because research shows that our behavior is more influenced by the people we trust in our network).

OK, now that I’ve made my pitch for the grand cause of science, let me just make a small comment about risk.

We are taking risk all the time.

I’m taking a risk by being on an airplane as I write to you (not just because of COVID, but just the simple act of being in the air protected by a thin piece of metal is a huge risk).

But, we need to think about risk in terms of a. population-wide probabilities, and b. whether the risk is outweighed by the benefit

Often, our concept of risk can be skewed by an anecdotal story we heard once from a friend.

I think about the time my mom read an article about a girl who died sledding because she rammed into a tree and was nervous about us going sledding.

Well, how did I think about that risk?

A. If we take all the children who have ever gone sledding, how many have died before? I don’t have the data on that, but I bet it’s a very small number.

B. I thought about the benefit of whizzing down the hill, my hair flying in the wind, and that benefit definitely outweighed the infinitesimally small risk of getting killed.

So I sledded down the hill (and I’m still alive to tell the story!)

Ok, so that’s a bit of a silly comparison, but we can think about the vaccine in the same way.

Is the vaccine completely harmless? Could it potentially have a long-term effect 20 years from now?

Maybe. But the probability is so small, that experts say you’re at more risk of death crossing the road than taking the vaccine.

And then if you think about the benefit – that if enough people take the vaccine, we could have normal life back by summer of next year (this is my optimism speaking here), I think the choice is obvious.

Of course, there’s risk mitigation – so if you’re pregnant or have had a serious allergic condition, maybe don’t jump at the chance to take the vaccine.

But if you’re healthy and eager to return to normal life, I hope this post helped you feel more educated, assuaged some of your fears and as the year comes to an end, made you a bit more hopeful for the year that is to come.

Merry Christmas and happy holidays, friends!

Resources

Scientific articles

Science of the various vaccine technologies

Commentaries on remaining scientific questions

News articles

Medium: Every COVID-19 vaccine question you’ll ever have answered

Sciline: COVID expert quotes on vaccine development

New York Times: How the Pfizer/BioNTech vaccine works

CBC: Pfizer/BioNTech vaccine FAQ

CTV: Scientists raise alarm over signs of vaccine hesitancy

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