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Professor Rod Dunbar, a leading expert in human cellular immunology, talks to Phil Taylor about work being done in record time to develop a Covid-19 vaccine, what Kiwi scientists are contributing, and the damage done by the anti-science movement.
While revolutionary bio-technologies are spurring the global effort to produce a vaccine, progress has been undermined by "campaigns with an anti-science feel", says Dunbar, director of the University of Auckland-based Maurice Wilkins Centre, which focuses on discovering new medicines and vaccines. "There has been a decimation of trust in expertise, in science."
There are already more than 50 vaccine candidates, with Johnson & Johnson aiming to start human trials in September.
"At the moment we have an unprecedented array of different formats of Covid-19 vaccine, from traditional to very innovative platforms using new technologies," Dunbar says.
"The positive thing for humanity is that we have never been in a better position to fight this at speed, so there is tremendous optimism that one or other of these platforms will eventually come through."
Are New Zealand scientists working on a vaccine?
"Several groups are helping out through international collaborations, supplying not just ideas but actual vaccine components.
"Could New Zealand develop its own vaccine and scale it fast enough? The honest answer is no. But our scientists can be involved in that deeper understanding to help the vaccine effort; the actual biology of the virus, what kind of immunity is most effective and what the components are of a good vaccine.
"We are asking colleagues overseas whether any of the components we have in our various labs around the country are of use, and the answer is probably yes."
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How quickly have scientists reacted?
"One thing that's moved incredibly quickly is identification of the likely targets for immunity – the bits of coronavirus, effectively – that you want to put into your vaccine.
"That's due to the rapid release by the Chinese of the virus sequence and also previous work done, particularly with the Sars [Severe Acute Respiratory Syndrome, 2002-2004], which is very similar."
Crucially, work on Sars found molecular targets on the outside of the virus, particularly the spike or S protein. When high-quality antibodies are applied to the spike, the virus is neutralised.
"It's good data as Sars-CoV-2, the coronavirus that causes Covid-19, shares 80 per cent to 90 per cent of its genetic material with Sars - hence its name. So scientists knew what looked like a really good target on this virus."
How does the vaccine protect against a virus like Covid-19?
Dunbar likens it to putting a snug, sticky coat over the spike protein on the virus, which is shaped like a spiky mace. Our bodies' B-cells, which make antibodies, have sticky molecules. "What we are trying to do is make a molecule that has a lump of - let's call it Blu-Tack - on the end of it that fits perfectly around the particular [Covid] spike protein so it can't be used to enter the cell."
All viruses in the body use these kinds of spikes to attach to receptors on the surface of cells, allowing the virus to penetrate. Once inside, the virus takes over the cell's reproductive machinery to produce more copies of itself, before breaking out again, killing the cell in the process.
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While each spike is slightly different, the exact shape of the target Covid-19 spike protein is known because it's been studied in record time. "We know its molecular structure right down to angstrom level, down to the atoms."
That spike is called an antigen, because the body recognises it as foreign and prompts our B-cells to produce antibodies.
Each B-Cell has a slightly different shape of Blu-Tack on the end of it. "The body puts that spike protein up against millions of different B-cells, and the one that fits the spike the best suddenly starts to grow and pump out antibodies, [which] all have this Blu-Tack on the end that can stick to that spike.
"You want to generate bits of Blu-Tack that not only stick to the spike but also stop the spike from sticking to the cells they are trying to infect. That's called a neutralising antibody.
"That's what vaccines do for childhood diseases – measles, to use a current example. For most of your life, you will have very high levels of molecules with Blu-Tack that latch on to the measles virus and coat it, and stop it getting into your cells."
If the shape of the spike protein is not manufactured exactingly, antibodies may not stop the virus infecting the cell and the vaccine will fail.
"That won't be known until the clinical trial is done."
Have trials begun?
Trials of potential vaccines started in March using new messenger RNA vaccine technology that is unproven.
"The steps are to prove the particular vaccine design can make antibodies in an animal, then test to see whether those antibodies can neutralise the virus.
"Then you have to prove to regulators that your vaccine is likely to be safe in humans."
The first phase of that involves a small group of healthy volunteers who are monitored for side effects, such as fever or a toxic response around the injection site.
"Even at that early phase you can see whether they are developing a good immune response, and you can then take those antibodies and put them on to the virus to see if they coat the virus and stop it infecting cells."
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On March 16, Jennifer Haller, operations manager for a Seattle tech company, became the first person outside of China to be given an experimental vaccine against the pandemic virus.
She is one of 45 people to receive a vaccine made by US biotech company Modena which, along with China's CanSino Biologic, are the first to begin Covid-19 vaccine trials.
Last week a partnership between Johnson & Johnson and the US Government agreed to spend a billion US dollars on a possible vaccine engineered from a virus that causes common colds but has been disabled so it cannot replicate. Scientists will stitch in a gene for the surface protein from Covid-19.
The company says the project is not for profit and if the vaccine is passed for use, it will be accessible to all through some global mechanism yet to be determined.
That sort of money helps, says Dunbar. "Once they have a vaccine that works in the lab, they think their phase one trial will take only six weeks, an incredibly short time."
Bigger phase two trials are required to confirm a vaccine works in practice.
New methods designed during the Ebola outbreak have shortened this stage. Vaccines are taken to an area where the epidemic is running and given to one group of people likely to be exposed to the virus, then infection rates are compared with another group given a placebo.
"At that point you know you've got a vaccine."
The third and final stage – proving the vaccine is better than existing medicine – won't apply, as there is no existing medicine for Covid-19.
Are there hidden risks?
"There is a possibility the vaccine could make the disease slightly worse. That's why we need caution around the timeframes and why we need to launch lots of ships to fight this, because not all of them are going to make it to the other side."
Won't the profit motive work against Big Pharma sharing information?
Dunbar says that although drug companies will want to win the race to produce a vaccine for the prestige, which could lead to future profits, organisations such as the Coalition for Epidemic Preparedness Innovations (CEPI) and the Global Alliance of Vaccine Initiatives (GAVI), are intensely focused on making sure everyone shares their vaccine designs.
Are you feeling confident?
"While I'm 95 per cent confident we will get there, there is always that little bit of doubt.
"Even with vaccines that seem really promising, it's not until they are given to people who are exposed to the virus that you can absolutely be sure they will be protected and that the vaccines are not going to enhance the virus. You just can't predict that."
When will a vaccine be ready?
"It's 12 to 18 months away from when work started, and that is record time and only possible because of the amazing power of new molecular biology techniques and vaccine-production techniques, which have converged.
"The positive story is the world is amazingly well-equipped now."
The volumes required may be an issue, however. Johnson & Johnson, for example, has the ability to produce hundreds of millions of vaccines in a relatively short time, but billions will be needed.
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Could the world have been better prepared?
Yes, says Dunbar. Central agencies such as CEPI and the World Health Organisation were planning for such a pandemic but were underfunded, particularly by governments. They called it "Disease X", because no one knew exactly where it would come from.
"After this event, hopefully the world is going to realise we need to take some of the enormous wodges of cash that the financial system is generating and put it into proper biological research and vaccine-production facilities so we can respond even faster next time.
"We need to have factories ready to go to produce particular platforms of vaccines … [for] each virus family. We are in a pretty good position but we could have been in a better position if people had listened to the experts."
Prominent among those experts is Balclutha-born Professor Robert Webster, a world-renowned virologist. "People like Robert have been talking about this for a long time," says Dunbar. "Every biologist knew this was a problem but the financial incentives to work on it at large scale have not been there.
"The real tragedy is vaccines being undermined by social media campaigns with an anti-science feel [that has infected] high levels of government, especially in the United States but also in the UK.
"There has been a decimation of trust in expertise, in science. This is the classic example of how [that] has been incredibly damaging to our resilience as a species.
"It is only science that gets us out of these messes."
