In My View: Samir Dervisevic, Consultant Virologist
Consultant Virologist Samir Dervisevic has led our Specialist Virology Centre throughout the pandemic, testing patients’ samples across Norfolk and Waveney and conducting research to build our understanding of Covid-19 and help develop a vaccine. Now that a vaccine is here, he gives his views on the impact it could have.
“If you ask me as a Virologist whether I’m surprised by the warp speed at which Covid-19 vaccines have been developed, I have to say that I am not. If we look at the chain of events leading up to this moment, we can see why so much effort has been made.
“Just one year ago, in December 2019 – and now we learn it may even have been in October or November 2019 – cases of pneumonia of unknown cause occurred in the province of Hubei in China. In January 2020, a new coronavirus was identified as the aetiological agent and the genetic sequence of the virus became available. On 11 March, the World Health Organisation declared a pandemic and, since then, there have been worldwide more than 70 million cases and, sadly, 1,590,000 people have lost their lives.
“When epidemiologists were asked when there’d be a vaccine, the immediate answer was that the process of vaccine development meant that for any potential candidate vaccine we, as clinicians, scientists, governments, regulators and the public, needed scientific evidence of its efficacy and safety. Although giving any target day for the release of the vaccine would have amounted to speculation, some estimates in early spring 2020 stated that it might take at least 18 months to develop the first effective vaccines and therefore the likely date was spring 2021. However, the considerable effort made by scientists, pharmaceutical companies, governments and clinicians to develop the SARS Cov-2 vaccine resulted in an earlier than expected release of data from the clinical trials. In the autumn of 2020, the SARS CoV-2 vaccines moved into phase three clinical trials and, on 2 December, the Pfizer BioNTech vaccine was given emergency use authorisation by the UK regulator, the Medicines and Healthcare products Regulatory Agency (MHRA), making the UK first country to begin immunisation programme.
“Under normal circumstances it would take much longer than nine months since the pandemic was declared to release an effective vaccine – this process usually takes five years. However, these are not normal circumstances and several factors may explain why there is an emergency use authorisation for the Pfizer/BioNTech vaccine. We still do not have effective antiviral treatments for this disease and therefore immunisation is the only answer to this public health emergency.
“In public health emergencies, such as a pandemic, the vaccine development process may be atypical and national governments, universities, academics, clinicians and many, many others joined the race to find a vaccine and stop the disastrous impact of the pandemic. There has been unprecedented global collaboration and a huge amount of research. Fortunately, we also benefitted from the work done to find a vaccine for the SARS CoV- 1 following the pandemic in 2003, a closely-related virus to the current pathogen causing pandemic. Moreover, in the UK for instance, there has been pandemic preparedness over the last decade and different consortia such as the ISARIC have been preparing for such an event for well over six years.
“Generally, pharmaceutical companies take years to develop vaccines because funding is hard to find but, this time, a great amount of funding for the vaccine clinical trials has been released early on. Governments invested hundreds of millions of pounds, giving the vaccine companies the confidence to go ahead.
“The Pfizer/BioNTech and Moderna vaccines are messenger RNA vaccines which use fragments of the virus’s genetic code to create an immune reaction, while the Oxford University / AstraZeneca vaccine uses an adenovirus vector – a safe, engineered virus that produces an immune reaction. The mRNA type of vaccines have a completely different way of production from the classical vaccines. They are not produced in eggs or cell lines but in plasmids. They provide flexibility in the design and expression of vaccine antigens that mimic the structure and expression of the antigen during natural infection. The advantage of the mRNA manufacturing platforms is the ability to rapidly produce large quantity of vaccine doses against a new emerging pathogen such as the SARS CoV-2.
“I understand that some people might be worried about safety because of the speed of the first vaccine approval, but no corners have been cut – tens of thousands of people have taken part in clinical trials and been followed up to check whether they had any adverse reactions, and expert scientists at the regulatory agencies have interrogated and evaluated the data before making any decisions. Efforts to work on vaccine development much faster than usual to address the ongoing Covid-19 pandemic have not sacrificed scientific standards, integrity of the vaccine review process, or safety.
“The Pfizer vaccine must be stored at minus 70 degrees to prevent the RNA from disintegrating and can only be defrosted once, although work is in progress on a thermostable version. This means it has to be stored in hospitals and bigger centres, making distribution more complex. Other vaccines will be easier to store and transport. It’s likely that the government will choose to deploy all available vaccines because there won’t be enough of just one for the whole population. Whether the regulators eventually settle on small number of vaccines remains to be seen.
“Vaccines are just the start and the global outlook depends on how successful we are in tackling the outbreak. The efforts to immunise the population in one country or one group of countries will not stop the pandemic. Epidemiologists still do not know whether this virus will become a seasonal virus or subside and disappear, similar to its related SARS CoV-1 virus. The key issue is the availability of safe and effective vaccines for most or all people in the world who would like to receive it. This issue has moral, technical and scientific components.
“Data from antibody testing suggest that roughly 90% of the population are susceptible to SARS CoV-2 infection. Epidemiologist state that between 70-75% of the population would have to be immune, either because of immunisation or natural infection, to achieve the collective protection of ‘herd immunity’. This means that 5.6 billion people worldwide would need to be immune to end the pandemic. This underlines the moral obligation to be immunised, to protect others as well as yourself.
“And of course we need to look at this on a global scale, having a global response and different bodies working together. The alternative possibility is that it may take years to achieve worldwide immunisation and end the pandemic. How fast this pandemic stops depends on how well we work together – it could take years to achieve if there is no global appetite and governments focus only on their own countries. Many institutions, such as the World Health Organisation, are already collaborating to ensure the equitable distribution of the vaccine. We need to take away the politics and work together – viruses do not respect countries’ borders and if we want to stop it, we must stop it everywhere.
“It’s also encouraging that AstraZeneca stated they will produce their vaccine on a not-for-profit basis – at £3 a dose, it’s much cheaper than Pfizer’s, at £15, and Moderna’s, at £20, making it much more affordable for developing countries.
We need to co-operate
“The pandemic has taught us that we are vulnerable and we need to co-operate. There will be more pandemics but what we have learned this time has set a pattern to help us deal with the threat. We now have diagnostic equipment in our hospitals so we don’t become overwhelmed by samples we can’t process, which will help to manage the spread of any future infection. The vaccines we have developed will help us too. We know now that there are mutant variants of Covid-19 but we believe that currently approved vaccines are still effective.
“It could be that Covid-19 disappears or we may need annual immunisation – we do not yet know. Whatever the case, we need complete transparency to tackle the flood of anti-immunisation content on social media, making the compelling evidence from the clinical trials available for public scrutiny so people can make their own judgements and not be misinformed. Immunisation is currently the only way to make everyone safe from this disease and enable us to resume our normal lives, so we must all play our part to make sure that it happens, whether that’s on a personal or government scale.”