At unprecedented times like these, the world is in desperate need of relief. Across the world scientists are working to gain a better understanding of the virus causing this COVID-19 pandemic, so that a cure can be developed. In the past few months, there have been many ‘break-through’ solutions come to light, although none have proven to be effective enough to be considered a cure or prevention.
Over a hundred vaccine programmes have been initiated across the globe, however it is likely that a large percentage of them will never progress further than the laboratory. 13 of these programmes have gone onto clinical trials, 2 of which in the UK; Oxford University and Imperial College London have both started human trials, with the aim of evaluating the immune response activated by the COVID-19 vaccine.
On the 24th of June, Imperial Professor Robin Shattock and his colleagues commenced the human trials for their ‘Imperial COVID-19 Vaccine’. This is following previous tests carried out in animals that showed that the vaccine triggered an effective immune response, whilst being safe to use. Upon successful completion of the trial, they intend to distribute this vaccine in the UK and overseas. Currently this phase of the trial involves 300 healthy volunteers being injected with the novel vaccine, over the next few weeks. They hope to increase the number of volunteers to 6000 in October as they move onto the next phase of the trial.
Imperial have referred to their process of developing this vaccine as a ‘new approach’. Vaccines are typically based on weakened or modified forms of the virus which prompt an appropriate immune response, which can then provide immunity to the individual from the actual virus in the future, if ever encountered. According to WHO, Vaccines are one of the most effective ways to prevent diseases. Imperial’s new approach focuses on using part of the SARS-CoV-2 genetic code, rather than part of it. They were able to use this thanks to scientists in China, who sequenced the genetic code after acquiring isolated samples of SARS-CoV-2 from COVID-19 patients.
This genetic code, or self-amplifying RNA, will mimic the virus which will train the immune system to recognise and respond appropriately to COVID-19 without having to actually contract the virus. Fat droplets containing the RNA is injected in muscle (arm or leg), where it will enter the body’s cell and start replicating. This particular piece of RNA encodes for a ‘spike protein’ (S-protein) found on the surface of the virus. This particular protein is responsible for 2 primary tasks which play a vital role in host infection. The spike protein acts as the mediator between the host cell receptors and the virus, after which the protein assists the fusion between the host cell membrane and virus membrane, facilitating the virus’ entry into the cell.
Spike proteins are produced in the cytoplasm, which means that it does not affect the cell’s own DNA (genetic material). Once produced, the body’s immune system can recognise the protein as a foreign virus and initiate a neutralising antibody response, consequently providing protection from the whole virus in the future.
The Imperial trial requires participants to receive 2 shots 4 weeks apart. A blood sample will then be taken to determine whether they have developed an immune response to the virus causing COVID-19. To evaluate the true protective effectiveness of the vaccine, Phase III of the trial will compare a large group of people injected with the vaccine against a placebo group over the course of a year. This can only be done once the safety of the vaccine is assessed and although there are no particular safety concerns, the new approach alone necessitates proceeding with caution in order to reduce safety risks. Phase I of the trial, which began last week, involves the comparison of 3 different doses of the candidate vaccine, assessing any potential safety concerns and their ability to produce an adequate immune response.
Scientists at Imperial College London are able to recreate and generate copies of the RNA sequence using just enzymes in the laboratory, eliminating the need for animal or human cells. Another advantage of this vaccine is that only a small amount of the genetic code is required for the vaccine. 1 litre of the vaccine will equate to 2 million doses. Prince William has even expressed his excitement and fascination regarding this trial, adding to the optimism and hope that this trial may bring.
At the same time, it is important that we remain cautious during these uncertain times. Although this vaccine seems promising, there are still a lot of unanswered questions regarding coronavirus and it is clear that we do not know the full extent of the disease. Gaining a better understanding of the disease and how it affects our body can subsequently give way for more tailored and effective treatments which can cater for a wider population.
Another note to mention is that not everyone responds to treatment in the same way, so a question to ask is whether one vaccine will be enough to provide immunity to an entire population? Instead of competing against each other, scientists working on different vaccines around the world have agreed that the fight is against the virus, not each other. In hindsight, having multiple effective vaccines will help cater to such a large population.
This pandemic is undoubtedly putting a strain on the endurance and resilience of us as an entire population. Nevertheless, it is essential that we stay hopeful and work together to fight through these trying times in any way we can, whether that is participating in trials to contribute to the progress or just making sure to keep our loved ones safe and well.