REVIEW
A vaccine – is it possible? And by when? Laureate Professor Peter Doherty
A live virus is also the ‘gold standard’ for virus challenge studies in animals, a usual part of the vaccine testing regime. The animals with COVID-19 that are particularly useful for vaccine evaluation include genetically modified mice that have the ACE-2 (Angiotensin Converting Enzyme 2) molecule – the molecule with which the virus binds to get into the cell. The Walter and Eliza Hall Institute of Medical Research (WEHI) have had these mice for some time. Scientists at the Doherty Institute have had some access to the PC3 (Prostate Cancer Cell Line) level mouse facility at the WEHI for virus challenge studies, using a natural variant of the SARS-CoV-2 virus that binds ACE-2 to the mouse, and are currently developing another collaboration in Melbourne that will allow them to do more extensive animal studies with live virus.
In our 2nd October Special Online Event we heard from Laureate Professor Peter Doherty on vaccines for the Severe Acute Respiratory Syndrome Coronavirus 2 virus (SARS-CoV-2) that is responsible for COVID-19 (the coronavirus disease). Professor Doherty began by pointing the audience to his ‘Setting it Straight’ blog on the Doherty Institute website (https://www.doherty.edu.au/ news-events/setting-it-straight), where he aims to write about 800 words a week. With about 26 episodes under his belt, Peter thinks of these as his weekly sermons and as having stemmed from his Methodist upbringing and lay preacher tendencies! He then progressed to the topic of vaccines, noting that Australia got on to the research and development of vaccines ‘fast and well’.
Another animal that is particularly useful is the hamster. Australia had not previously used these desert-dwelling animals because, if released accidentally into the wild, they would multiply quickly (like rabbits) and have devastating effects on the native fauna and flora. However, a facility in the United States has now been identified for virus challenge studies in vaccinated hamsters.
The Chinese published the gene sequence of the virus in mid-January, very shortly after they had isolated the virus. Once the gene sequence was published, that was all the information needed by vaccine developers to get on with making vaccines. Australia reported its first case of COVID-19 on 24thJanuary 2020. Fortunately, the returning traveller had been very responsible and had selfreported before presenting and being admitted to the Monash Medical Clinic. Scientists at the Doherty Institute gained a sample from this patient and after isolating the virus were the first to supply the infectious virus to other scientists around the world.
The Doherty Institute now has two vaccines under development, one further ahead than the other. The Institute has also been undertaking a lot of testing to help CSL and the University of Queensland with their novel vaccine being made under the umbrella of the Coalition for Epidemic Preparedness Innovations (CEPI). CEPI was cofunded by the Bill and Melinda Gates Foundation, The Wellcome Trust and a consortium of nations, and launched formally at the World Economic Forum in 2017. The Chair of CEPI is Jane Halton, National COVID-19 Coordination Commissioner and, previously, Secretary of the Australian government’s Health and Finance departments. CEPI endeavours to develop vaccine platforms that can be deployed in global emergencies. Gavi, the Vaccine Alliance, and the World Health
This was a very important first step for vaccine development for a number of reasons. Firstly, scientists need the infectious virus to do virus neutralisation tests that detect the presence in the blood of antibodies that prevent the infectivity of the virus. These virus neutralisation tests are the ‘gold standard’ of measuring antibodies in a virus infection. (Various molecular surrogate tests have been developed since.)
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