When can we expect a COVID-19 vaccine?

The global COVID-19 pandemic is changing how vaccines science is undertaken and will serve to teach us a great deal about what can be achieved in terms of the application of emerging vaccines technology, collaboration and speed. As this is a new virus, identified only at the beginning of 2020, we are still very much at the learning stage in terms of how it behaves in populations and over time. However, a vast amount of scientific and clinical experience is already being applied to this challenge, including the knowledge of other complex viruses, and indeed other coronaviruses such as SARS and MERS, and also flu, which remains a major global health threat annually.

In non-pandemic periods, a new vaccine can take up to ten years to develop and get approved. This is not because of any lack of urgency on the part of the scientists and manufacturers—far from it—this is largely due to the need to establish the efficacy and safety of a vaccine through large-scale, long-term clinical trials, regulatory processes which differ across geographies, and the high level of complexity involved in manufacturing any new vaccine.

In this pandemic situation, all of those things, while no less challenging, are being compressed into an unprecedented timescale in order to address the human tragedy which is unfolding around the world. We are all moving at a pace which has never been seen before in the development of vaccines. While I am personally encouraged by the degree of scientific collaboration that is in play and remain positive on our hopes for success, it is too early to know for sure if these endeavours will result in an effective vaccine against COVID-19. The signs however are very encouraging.

A range of approaches in vaccine development are being employed by multiple research teams globally, some of which are more tried and tested, others which represent the more experimental sphere of vaccine science. This variety in the application of vaccine science could be the key to beating this virus. It is also in part why we are seeing the variation in progress being announced for the development of different COVID-19 vaccines.

New approaches including mRNA vaccine candidates, for example, can move through the earliest stages of development and testing more quickly and generate early data faster than some more established approaches. But all of these candidate vaccines, if they progress beyond the lab, need to enter into clinical trials in healthy human populations. Initially, these are small scale and then progress into much larger safety and efficacy trials, which must be robust enough—conducted in a sufficiently large enough group of people, and in an environment in which the virus itself is in circulation to generate meaningful results.

We must remember that trials for vaccines are different and, in many ways, more challenging than for those for a new medicine. With a new medicine, we look to identify sick patients and construct trials to assess the outcomes of those patients using a newer treatment in comparison to those using other treatments or a placebo. With a vaccine study, we need to administer the new vaccine to healthy people who may never actually have got sick from the disease we are investigating and monitor how many people are prevented from becoming ill in a population. This can be a more difficult assessment to make.

Our best estimate at GSK, at the outset of the pandemic, was that a successful vaccine against this novel virus would take from a year to eighteen months to become widely available. We also recognised that the world was likely to need more than one vaccine, and so our approach has been to make our specialised and proven vaccine adjuvant technology available to multiple research teams around the world, in the hope of at least one of these projects resulting in a new vaccine.

Factoring in all of the stages mentioned above, and working with collaborators including Sanofi, another global scale vaccine specialist company, we continue to estimate that we will be looking at the second half of 2021 before a successful vaccine from one of our collaborations could be mobilised. It is certainly the case that others are proposing a shorter timescale, and given the global need, as a scientist, I can only hope that a safe and effective vaccine for COVID-19 is available as soon as possible and we are doing everything we can to make that happen.

I know that the collaborations that GSK is involved in will only move towards the approval phase of development and widespread use beyond clinical trials once we are assured that the appropriate safety and efficacy testing has been completed, and this is factored into our timeline. Speed is not the only or even the primary criteria—but it is clearly a huge motivator to all teams involved.

The next phase of the global scientific programme to address this pandemic will be one of scrutinising the data we start to see emerging from these clinical trials. This is beginning to happen already, and we have to be thorough in our evaluation of these data, because only this information from the use of candidate vaccines in people exposed to the virus can really show us if we are achieving what we hope to achieve. As a vaccines’ scientist, in the world’s leading vaccines developer, I am excited and hopeful that what we will see tells us what we are all waiting to hear—that this global scientific endeavour has delivered safe and effective vaccines that can be manufactured at scale and mobilised globally to prevent COVID-19.

I also hope that what we learn from this process means that in the future, we face infectious diseases, including any future pandemic, better equipped with vaccines technology, better prepared global mechanisms and a collaborative mindset that further advances immunisation as one of the most powerful human health interventions we have available to us.