Vaccines: Getting Us To The Other Side
What are the real prospects for a COVID-19 Vaccination?
We hear “COVID-19” everywhere from news programs, radio, social media, (Zoom) conversations, and even in our dreams?! The roughly 100 nanometer-wide virus causing COVID-19, and its path of global destruction has been dominating our daily lives.
As I write this, the global number of reported confirmed cases has exceeded 2.7 million and the death toll is now over 187,000. Collectively, as a human population, we are feeling its wrath. So it’s easy to get lost counting the days since social distancing and faltering economies have become the new normal.
As we adjust to this apocalyptic reality, no doubt many of you are asking questions like: Why don’t we have a vaccine yet? When will we have one? What other challenges lie ahead? So I went searching to find some answers.
Here’s what I found about the real prospects of a COVID-19 vaccine and what the challenges might be in getting us to the other side of this pandemic.
Question 1: Why don’t we have a vaccine yet?
There is currently no licensed vaccine against SARS-CoV-2, the coronavirus that causes COVID-19 (which stands for Coronavirus Infectious Disease 2019), because it had not previously infected humans. Therefore, humans have not yet developed immunity against SARS-CoV-2, and this has resulted in rapid transmission across nearly every country in the world. That’s why we need travel restrictions and social distancing measures to reduce the spread and #flattenthecurve.
Understanding Coronaviruses
Coronaviruses are a family of viruses that were first identified in the mid-1960s, and infect a wide range of hosts. Of the 39 species of coronaviruses, three cause severe and potentially deadly infections in humans, resulting in epidemics: Severe Acute Respiratory Syndrome Coronavirus SARS-CoV in 2002–2003 and Middle East Respiratory Syndrome Coronavirus MERS-CoV in 2012, and now, SARS-Co-V-2 that emerged from Wuhan, Hubei province in China in 2019.
Despite years of development efforts, there is still no licensed vaccine for either SARS or MERS. The respective epidemics ended before vaccine development was complete, and there were also issues with funding allocation and efficacy.
However, previous research of SARS and MERS vaccine development has been the basis for developing a COVID-19 vaccine. And with the overall number of deaths from COVID-19 far outweighing that from SARS or MERS combined, there is definitely an immense global push to find an effective vaccine to curb this pandemic.
Why we need a vaccine
So why are we hoping for a vaccine at all, and what will it do for us?
A vaccine is a type of medicine that works by training the body’s immune system to fight a pathogen or disease-causing germ, without having to get the disease first.
A viral vaccine contains the inactivated virus that we want protection against. Specifically, the proteins on the surface of a virus, referred to as antigens, are what our immune cells can look for to say ‘hey, that’s a virus!’ So a vaccine shows these antigens to our immune cells, and they trigger production of antibodies, which are specialised for destroying that specific virus.
Think of a vaccination as a ‘wanted’ poster- the immune system is told what to look for so that if we do come across the real bad guy, it can respond quickly and get rid of them before they cause any harm.
Now, let’s consider a vaccine for COVID-19.
If it is effective, individuals who receive the vaccine will become immunised. This means that even if they were to come into contact with the real coronavirus, they would be protected and will not experience COVID-19 and its terrible symptoms.
If most people in the community are immune (this can occur by vaccination or after recovering from the disease), then even vulnerable populations without immunity can have protection against the disease. This is known as herd immunity. There has been debate and controversy on how to achieve herd immunity in the safest way.
“… the proper context of herd immunity is a desirable outcome of a vaccination program”. — Kerryn Phelps, former president of the Australian Medical Association and ex-federal MP.
Instead of simply ‘waiting it out’ so that the majority of populations are infected and only potentially recover, our best hope for widespread protection is to develop an effective vaccine within the timeframe of the pandemic.
Now you might be thinking, but what about those who already have COVID-19? That’s an important question because while vaccines help prevent disease, they do not treat it. For that, we generally need antiviral drugs. You can read more about what scientists are doing to test antiviral drugs here.
Question 2: When will we have a vaccine?
Now this might be the most burning question, considering you are probably reading this from the confines of your own home, wondering how much longer it’s going to take… As it turns out, when or if we will have a vaccine, depends on what we mean by ‘having a vaccine’.
‘If you mean one that can be used in a mass vaccination campaign, allowing us all to get on with our lives, then 12 to 18 months is probably right”. — Marian Wentworth, president and CEO of Management Sciences for Health.
This infographic based on data from the Milken Institute, helps us visualise a timeline for the three approaches for treatment and prevention of COVID-19: using existing (repurposed) drugs, antibodies, and vaccines.
If you’re thinking 12–18 months seems like forever, let’s put that into perspective.
The traditional process of developing a vaccine is a very lengthy and expensive process, often taking over 10 years. This is due to careful evaluation of effectiveness and safety at each step, as well as accounting for high failure rates.
So creating vaccines is no easy feat, let alone ‘at pandemic speed’. Some steps actually need to be completed in parallel, or at the same time to accelerate the process. We’ll get to how this can be a problem later on.
Research institutes and biotechnology companies are working hard to meet the three key needs for the COVID-19 vaccine: speed, scale, and global access. Of course, this is on top of the imperatives for safety and efficacy.
According to this Nature review there are 115 vaccine candidates, and 1–5 candidates are in phase 1 or 2 clinical trials, as of April 8th. Read here if you want to learn more about what clinical trials are. And for those who want more detail on the top vaccine candidates, watch this educational video by Osmosis.
So considering all the challenges and pressures of vaccine development in a pandemic, it is truly amazing to see how much progress has already been made.
Question 3: What are the challenges ahead?
Unfortunately, vaccine development is even more complicated than just a waiting game…
Understanding the Challenges
Even with potential prospects for a COVID-19 vaccine, there are many other obstacles to face ranging from; technical difficulties of reinfection and combating potential viral mutations, to ethical dilemmas of human challenge trials and fair access.
Technical difficulties:
According to Professor Ian Frazer, who worked on the successful Human Papilloma Virus (HPV) vaccine: it has been hard to make safe vaccines for coronaviruses in the past, partly because the site of infection- the upper respiratory tract, is not well protected by our immune system.
Then there is the issue of getting an effective (and safe) vaccine out fast enough before the coronavirus itself mutates and changes shape. That would mean the vaccine is no longer effective, and we’re back to square one.
To consider how this would impact vaccines, let’s imagine playing Where’s Wally. Vaccines are trained to identify the outside of a virus like we’re trained to identify Wally’s red appearance. But if Wally disguised himself as Odlaw in black, we can’t find him. Viruses do the exact same thing by changing how their outside looks, called antigenic “drift” (small changes) or antigenic “shift” (big changes which can result in new subtypes). Antigenic drift occurs commonly in Influenza virus, and is the main reason why we need to get a flu vaccine each year as the viral strain mutates.
Although SARS-CoV-2 is in fact evolving, the changes are very small and do not seem to have resulted in new sub-types. One genetic analysis suggests that there could actually be 2 strains of the SARS-CoV-2, but it has received some criticism and has not been confirmed.
However, viral mutations can be a big problem for COVID-19 vaccine development, as it calls into question how long immunity, if any, would last from a particular vaccine and also raises the issue of reinfection.
Ethical Dilemmas:
Cutting down on time for vaccine development doesn’t come without its costs. In the normal timeline, vaccines go into human trials only after tests for safety and effectiveness in animals. But two of the top candidates, Moderna and Inovio vaccines, are in human phase I trials at the same time animal trials are happening.
Participants who are involved in these trials don’t really risk getting the virus itself but the safety of the vaccine is unknown, and it is unsure how the immune system will respond to it.
So while many of us might feel impatient for results, we also have to ask ourselves, would we risk taking a vaccine if it could potentially do us harm?
Furthermore, the controversial approach of human challenge trials, in which participants are injected with the virus (whether or not they have been vaccinated), has started gaining some traction. This highlights the importance of understanding risks involved in human trials before raising your hand to volunteer in one, and that ethics committees have a lot of work cut out for them.
Another thing to keep in mind are the massive financial costs and risks for vaccine developers. In fact, some smaller companies have had to give up or have gone bankrupt in their pursuit for a vaccine.
“Part of the challenge of financing biomedical innovation is the underlying risks that are involved with these efforts.” — MIT Sloan finance professor Andrew Lo.
Finally, with a lot of money and a lot of risk involved, it is important to keep things transparent and fair. It is up to all parties involved in vaccine production, including all of us raising our voices, to help build a system that ensures fair allocation and fair pricing, should a vaccine become available. Because whether we like it or not, we’re all in this together.
“If anyone is sick anywhere, it means all of us are threatened everywhere”. — Dr Rishi Desai, Paediatric Infectious Disease Physician
Will we make it to the other side?
After exploring some of the COVID-19 vaccination prospects, and the seemingly mammoth obstacles in their way, you might be feeling somewhat disappointed or hopeless… that there is not yet a miraculous solution and that we might be inside our homes, having online conferences and resorting to ‘social dis-dancing’, for longer than expected.
But there is certainly hope that we will get to the other side, thanks to the incredible work being done in the field of vaccine development and medical research.
“In uncertain times, we are witnessing one of the greatest moments in the history of science.”
Until we do get to the other side of this pandemic, we can only focus on what is in our control: doing our part to slow the spread, using reliable sources to filter out misinformation, and probably most importantly, looking after ourselves and one another.
Let’s hope that in the not too distant future, our playlist will end up looking like this…
Remember to always access reliable information and advice on COVID-19 from government sites (e.g. Australian Government Department of Health) and reputable agencies such as the World Health Organisation.
