How Close Are We To Getting a COVID-19 Vaccine?
Pharmaceutical companies and universities around the world are working towards finding a COVID-19 vaccine — as fast as possible. In the past few months, we’ve seen bold claims from Pfizer saying they could produce a vaccine by October this year and others claiming we’d have a vaccine by early January.
“Having a vaccine is one thing but you need to produce it at scale (…) it is not an easy thing to do,” said the Chief Executive Officer of AstraZeneca.
It is important to note that vaccines usually take years to develop, so to have an effective and safe vaccine by 2021 would be an incredible feat. There are several phases of the clinical trial process: the first step is the pre-clinical stage which involves testing the vaccine on an animal (usually a mouse model).
After the pre-clinical stage, vaccine testing must go through the following three phases:
Phase I involves testing the vaccine on a small number of volunteers to see if the vaccine is safe, effective, and to study the body’s immune response.
Phase II repeats the experiment on a larger sample — hundreds of individuals — to further test the efficacy of the vaccine and to observe any potential side effects.
Phase III involves a testing an even larger sample size (in the 1000’s) and is designed to look at and document any rare adverse events.
The UK has made deals with pharmaceutical companies including Pfizer/BioNTech and AstraZeneca to secure 90 million doses of the vaccine. The deal is to ensure that as soon as the vaccine is ready, the UK will have immediate access to vaccinate the most vulnerable individuals (i.e. immunocompromised individuals, the elderly, healthcare staff).
So, how close are we to getting a COVID-19 vaccine?
There are over 100 potential vaccines already in the pre-clinical phase, as reported by the World Health Organization (WHO), which is tracking the types of vaccines currently in development, their respective developers, and the stages of development they are in.
At each stage, fewer vaccines are reported. This is because many fail to pass the previous stage, likely due to documented side-effects too serious for widespread use or poor immune response.
No vaccines have yet been approved for use against COVID-19.
However, the bold claims made by pharmaceutical companies may show some promise in propelling scientists to develop a COVID-19 vaccine and speed up the clinical trial process.
Results from a Phase I/II single-blind randomized controlled trial was published in the Lancelet from Oxford University yesterday. The study involved individuals aged 18–55 years old without any COVID-19 symptoms or signs of the virus. These healthy adults were either injected with a chimpanzee adenovirus vaccine or a control vaccine.
The results were promising: There was a strong immune response from healthy individuals who received the chimpanzee adenovirus vaccine as compared to the control, suggesting that this vaccine may show signs of effectiveness. Moreover, no serious adverse side-effects were reported, alluding to the vaccine being safe for use — encouraging findings for researchers as they move to the next phase of the clinical trial.
Another study by Chinese biopharmaceutical company, Sinovac, is also poised to enter Phase III of the clinical trial for their vaccine. Results from Phase II testing indicated that roughly 90% of individuals showed an immune response to the vaccine. The sample size was large — 600 participants were tested. Furthermore, no severe side effects were reported.
These findings, promising as they are for researchers, are all the more exciting for the general public, which not-so-patiently awaits a vaccine that might enable a quicker and safer return to normal life.
Numbers drop off at each stage of clinical testing, but the winner of the race is just over the horizon as researchers get closer and closer to successfully producing a vaccine.
The way things are progressing, it is quite possible 1 out of the 3 vaccines currently in Phase III testing might receive the green light for production by the start of 2021.
However, with the demand for the COVID-19 vaccine so high, it is also important to consider: How many people will have access to the vaccine and who will have priority?
To learn more about how vaccines work read my previous article: COVID-19: Is a Vaccine Our Only Way To Defeat This Invisible Enemy?
