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‘It’s just a race against time’: Developing a COVID-19 vaccine


Evelyn Lewin


1/05/2020 12:27:36 PM

Examining the challenges of finding a vaccine, timeframes for development, and the progress of clinical trials around the world.

Researcher looking at vials
Experts at the University of Oxford are working to develop a vaccine. (Image: AAP)

‘It is not imminent.’
 
That is Dr Charmaine Gittleson, the Chief Medical Officer at CSL, talking to newsGP about when she believes a vaccine for COVID-19 will be available for use in Australia.
 
‘I would be very surprised if there was a vaccine available, particularly for Australia – and this is my personal belief – until 2021,’ she said.
 
Dr Gittleson said there are numerous challenges in the race to find a vaccine for SARS-CoV-2, the virus responsible for COVID-19.
 
The first relates to how SARS-CoV-2 gains entry into cells, which occurs via the angiotensin converting enzyme (ACE)-2 receptor.
 
This has been a problem when it comes to animal testing, because the two animals usually involved in the trial process – rats and mice – lack ACE-2 receptors.
 
Dr Gittleson said animals that do possess ACE-2 receptors include cats and Rhesus macaque monkeys.
 
‘The regulators are very specific on which animals [can be used] and you have to find an animal model that you can test for the disease,’ she said.
 
‘And so you either have to create transgenic animals, where they [genetically modify] an animal that has that receptor, or you have to go to the Rhesus macaque monkeys.
 
‘Both of those [options] are quite difficult.
 
‘It’s hard to get those monkeys – there are a lot of ethical issues there as well – and it’s quite hard to create transgenic mice.
 
‘So the preclinical work has been quite challenging for the COVID-19 vaccine.’
 
Further challenges in the process of developing any vaccine include determining the acceptable number of patients who will seroconvert in response to being vaccinated.
 
Dr Gittleson said that figure has not yet been determined for COVID-19.
 
Another challenge of vaccine development in general lies in identifying a standardised neutralising antibody titre.
 
That is designed to test whether being vaccinated against an infection will neutralise exogenous exposure to the virus, and thus offer seroprotection.
 
Throughout vaccine development, Dr Gittleson said, it is imperative to ensure no genetic changes have happened to the virus, particularly the part where the antibody binds.
 
Dr Gittleson said there have been changes in the genetic make-up of SARS-CoV-2 during the process of vaccine development to this point, but these changes have not been in the area related to antibody binding, and therefore have not affected vaccine development.
 
What is the world’s progress in vaccine development?
SARS-CoV-2 has been identified, its structure and antigen-binding site is understood, and individual laboratories have been able to develop the neutralising antibody test.
 
‘This is where science is at the moment with COVID-19,’ Dr Gittleson said.
 
Various companies, universities and laboratories around the world are now at different stages of vaccine development.
 
‘The most advanced is from a company called Moderna in the US,’ Dr Gittleson said.
 
‘They have an RNA virus and they have completed their phase one dosing, and they’ve submitted their phase two protocol to the FDA [Food and Drug Administration] and they’re hoping to be doing their phase two studies in July or August.’
 
Meanwhile, researchers at Oxford University in the UK are looking to start dosing of phase one in May.
 
‘Everybody else is at phase one,’ Dr Gittleson said.
 
‘In Australia, there’s the University of Queensland working with the CSIRO and they are also looking to move to phase 1 dosing in June.’
 
Dr Gittleson said other companies such as Johnson & Johnson, Pfizer and GSK (GlaxoSmithKline) are discussing starting phase one trails in September.
 
What is an approximate time frame for vaccine development?
That depends on the number of patients recruited for each phase of trials; however, phase one study can usually be done in around 3–4 months, Dr Gittleson said.
 
Phase two requires vaccinating more healthy volunteers and then waiting at least 28 days to monitor the antibody response, followed by up to 90 days for safety.
 
‘Then you have to clean the data, analyse the data, write the data up. You’re looking at another, at least, 3–4 months,’ Dr Gittleson explained.
 
‘So if you did a phase two in six months, you’re going fast.’
 
The fact phase three trials often involve around 6000–7000 people means it takes even longer to analyse and report on that data.
 
‘So you can be a year doing your phase three,’ Dr Gittleson said.
 
After all of the data is submitted to the regulator, Dr Gittleson said a ‘fast priority review’ takes around six months.
 
‘Maybe they will shortcut steps in some way and do this faster,’ she said.
 
‘But it’s usually six months for a priority review.’
 
After that, manufacturing processes are inspected and, once production commences, millions of doses will need to be made. 
 
‘That takes time,’ she said.
 
‘The industry quotes are saying, realistically, 18–24 months.’
 
Dr Gittleson said a report from the Oxford group said they could have three million doses of vaccine available by the end of the year.
 
‘And if they can, well done to them,’ she said.
 
‘But three million doses will go nowhere in a population of 60 million in the UK.’

Dr-Charmaine-Gittleson-article.jpg
Dr Charmaine Gittleson says she would be ‘very surprised’ if there was a vaccine available in Australia for COVID-19 before 2021.

Does the lack of other coronavirus vaccines mean development of one for COVID-19 may not be possible?
Naysayers are pointing to the fact there is no vaccine against the common cold to question whether one will be developed for COVID-19.
 
Dr Gittleson said there is a good reason no vaccine has been developed against infections such as rhinoviruses.
 
‘There’s no real value there in spending an immense amount of time and money on making those vaccines when the burden on society [of having a cold] is not huge,’ she said.
 
Conversely, she said a vaccine was developed for influenza because of its high mortality rate and burden of disease.
 
Furthermore, Dr Gittleson said a vaccine was ‘worked on’ during both SARS and MERS.
 
‘Why it didn’t go through for SARS and MERS is more related to the fact those diseases became self-limiting because the disease killed off the host very quickly and it wasn’t spreading, it wasn’t very infectious,’ she said.
 
COVID-19 has, however, a different course.
 
‘It’s highly infectious and it spreads before it has the opportunity to kill its host, and the majority of the hosts are not dying so they’re spreading the virus,’ Dr Gittleson said.
 
‘So this is quite different in terms of the epidemiology.’
 
Dr Gittleson is optimistic a COVID-19 vaccine will be developed.
 
‘There’s a number of different approaches, so you have to hope that out of those at least one will work and there are a number of organisations trying to do this,’ she said.
 
‘There’s a general hope that a vaccine will be developed.
 
‘It’s just a race against time.’
 
Takeaway message for GPs
Dr Gittleson said the ‘most important’ message for GPs at this stage is to continue encouraging patients to have their influenza vaccine.
 
She said the rate of flu vaccination in Australia has decreased because people are self-isolating.
 
‘But they’ve got to come forward for their flu vaccine for two reasons,’ she said.
 
Firstly, it is imperative not to overload the healthcare system with influenza admissions down the track, as such systems may already be overwhelmed in dealing with coronavirus admissions at that time.
 
The other main reason relates to burden of disease.
 
‘If there’s a second surge of the coronavirus during the winter once our restrictions are eased, people – particularly the elderly and kids – do not want to have two respiratory viruses, or [have them] back-to-back,’ Dr Gittleson said.
 
‘That would be an absolute disaster.’
 
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Dr Ramzan Bin Abd-Azis   2/05/2020 9:08:35 AM

It is a common sense to us that influenza vaccine imperative to lessen the hospital burden in the lights of CO VID -19 pandemic but as a Practitioner we are facing challenges to convince those antivaxers and some sceptics in the population mostly younger generation to vaccinate. Why don’t from now on the authority sponsors free fluvax for all at least until we developed COVID vaccine. If the excuse is not enough funding, just reduce the job seekers/ newstart allowance ( apparently now doubled) and introduce no jab no allowance policy.


Dr David Alan Wallace   2/05/2020 4:24:55 PM

Interesting that Dr Gittleson says that the rate of influenza vaccination is going down. In my practice it would be at least double what it has ever been before, and each new shipment has vanished long before the next one arrives.


Dr Helena Spencer   2/05/2020 8:00:04 PM

My practice is also doing a lot of vaccination for influenza . We have had alot of patients in their 70's and even 2 people aged 86 who had never had a flu shot before who were now prepared to be vaccinated.


Dr Ian Mark Light   3/05/2020 1:16:15 PM

Meanwhile we ought be producing Hazmat Suits or helping other lands produce them so we can see people as the chronic diseases are being less attended to .
Australia is strong in PCR testing and research re PCR to increase test specificity and turnaround times for results some claim 4 hour turn over .
Outside infrastructure projects with physical distancing are being planned to lessen unemployment.


Dr Dannielle Maria Kolos   7/05/2020 11:31:50 PM

I heard on USA TV FOX, that the COVID 19 viral protein has been grown on tobacco leaves, has beein froed in animal studies and may be ready for human use by the end of June?