This article is an edited transcipt from ABC Radio with perspectives on vaccines and COVID-19 rarely discussed. How are vaccines actually produced? Can they be contract manufactured in Australia? What new facilities are needed? Are vaccines like drugs, made from mixing chemicals?
The source is ABC RN’s Saturday Extra programme, hosted by Geraldine Doogue (GD). She interviewed two of the world's top virologists on 22 August 2020. Professor Emeritus Ian Gust (IG) is from the Faculty of Medicine at the University of Melbourne and a former Head of Research at CSL. He developed the vaccine for hepatitis A. Dr Jerome Kim (JK) is Director General at the International Vaccine Institute. It has the mission to discover vaccines and deliver them to developing countries.
GD: Ian, let's just for the sake of simplicity, assume that Oxford University has cracked the code and has found a vaccine. And it's on to stage three trials so let's assume that they're successful. What happens next?
IG: Well, what's happening at the moment is unprecedented. What would happen in a normal situation is that as you proceed through phase one-phase two-phase three studies, and you get greater confidence that you've got a product that is likely to be successful, you then try to develop the manufacturing capability to produce the vaccine at scale. Which means designing, building and validating a new production facility. But because of the urgency with COVID and because the financial risks that companies normally take are replaced by governments and philanthropic organisations, these things are happening in parallel. So we've got a very truncated process.
GD: Why do need new facilities?
IG: You’ve got to build a factory to produce the vaccine in very large quantities. And you've got to be able to demonstrate that you can produce it reliably every time.
GD: Jerome, one of the things I have come to understand is that you need specialised vaccine production labs or facilities. They're not just drug company facilities, there's a difference, isn't there?
JK: Vaccines are a little different from drugs. A drug is a chemical, a vaccine as a biological product, which means that the systems that they come from are living organisms, at least in the beginning. Or they come from living organisms. Some of the hepatitis vaccines are now made from cells but they start with a biological product which is inherently more complex. It requires a degree of attention to quality and attention to the final configuration of the product that is a little bit different from manufacturing a drug and showing that it has the right chemical formula.
In this case, you're actually making something from a living product, and then purifying it and subjecting it to all the kinds of quality controls that are necessary before you put a biological product into human being. So it is a much more complicated process, and that's in part why it takes five to 10 years under normal circumstances to get from start to finish.
GD: So all vaccines are effectively living products as opposed to just a collection of drugs.
JK: There is one exception now, and that is the RNA vaccines similar to the one being made by Moderna and one by Pfizer. RNA vaccines can be made chemically but it's complex, it's never really been done before at scale. And we don't have a good idea, at least I don't, of the final cost.
So we could chemically create this long molecule called RNA, then you have to pay for every step, you have to pay for all the chemicals. Some people would argue it's easier for us to characterise a chemical compound than it is a biological compound. Others would say it's easier and cheaper and faster for us to just make it biologically and purify it. Right now, we don't know which process is quicker, faster, cheaper, and safer.
GD: Can I check this with both of you. Basically, there are two types of vaccines. One confers sterilising immunity. This means the immune system is able to stop a pathogen, including viruses, from replicating, like measles is a classic example. And the other reduces its seriousness but not eradicating it. Is that it?
IG: The essential issue that could play a big factor with the COVID vaccine is that we have some extremely effective vaccines against organisms that circulate in the blood. Neutralising antibodies will completely prevent disease occurring. But we have other diseases where the infection occurs at the mucosal surfaces in the respiratory tract and in the gut. And there the vaccines that we've developed are much less effective. Think of typhoid and cholera and even rotavirus and flu. They give between 30% and 70% protective efficacy whereas with measles, mumps, rubella, tetanus, diphtheria and so forth are 95% and upwards effective.
COVID is a pathogen which affects mucosal surfaces. So the thinking is that this vaccine is more likely to have the protective efficacy of say a flu vaccine than for example the polio vaccine. The regulatory agencies, especially the FDA, have said that provided a vaccine will protect 50% of people who receive it from getting the disease, they are prepared to license it for widespread use.
GD: Could you explain about the mechanics, Jerome, of producing this. The idea that you can just scale up suddenly is something that I don't think has been fully discussed.
JK: Different organisations have different capacities. There are some companies that specialise in manufacturing vaccines for other people. We call them contract manufacturers. And so, the United States government has made deals, as part of Operation Warpspeed, with three different contract manufacturers. These are companies that specialise in making things for other people.
For instance, Emergent Biosolutions has the ability to rapidly switch equipment. They use disposable equipment rather than these giant stainless steel vats and stainless steel pipes. They try to do everything disposably which gives them a lot more flexibility to reconfigure rooms to meet the required standards for manufacturing and production. Their turnaround times are a lot faster and they can switch from one vaccine to the next vaccine. Not all companies have that capability. Some companies may make a polio vaccine under a certain level of biosafety. You could potentially with small modifications design the factory to make one of the Chinese vaccines which is a 'whole inactivated vaccine' that’s an old form of vaccine. If you have the right kind of facility, you can quickly manufacturer huge numbers of doses. Hundreds of millions of doses.
In this case, a whole inactivated vaccine presents the entire virus to your body's defense or immune system that allows you to make responses against not only the little spikes that people see on the models with the coronavirus spike, but also the other proteins in the other parts of the virus particle that may actually give you a better type of protection. The one complication for COVID-19 is that the vaccine has to be made under what we call ‘BSL3 conditions’, it's a very high level of biosafety in case the virus were to escape.
Not all countries have a BSL3 factory that's available, and it would take special construction and special permits and the process of proving that the factory can in fact do this safely is more extensive. If you don't have the preexisting capacity, it's much more difficult.
GD: Okay, the final word to Ian Gust. So where is CSL, what sort of vaccine would it be happy to produce, do you know the answer?
IG: No, there's a kind of a misconception that just because you've got a plant in the country which makes vaccines, you can make any vaccine. That’s not true because for most vaccines, the manufacturing process is unique for that particular project, and that particular product. CSL is a very large producer of influenza vaccines. It produces those mainly in eggs and in cell culture, but many of the vaccines that are candidate vaccines for the coronavirus infection are produced by other technologies, so it would mean CSL basically starting the whole thing from scratch again.
What seems to me more likely, at least in the short term, is that if an overseas manufacturer entered into a relationship with CSL, the overseas company would produce it in bulk in their production plant, ship the bulk to CSL who would then finish it and distribute it locally.
The full 14-minute version from ABC's Radio National can be found here. This article is general information only.