Episode 8 – ASF: a virus with no cure or vaccine
Harmless to humans, but deadly to pigs and wild boars, African swine fever (ASF) is a viral disease for which there are neither vaccines nor cures. In recent years it has spread across Europe and worldwide, causing serious socio-economic consequences in the affected regions. Join us for this episode of Science on the Menu, in which our expert Lina Mur explains the state of play.
Science on the menu, a podcast by the European Food Safety Authority.
Hello everybody and welcome to another episode of Science on the Menu. My name is James Ramsay and today we're going to be talking about animal health. Another animal health issue actually: You may have listened to the previous podcast we did on Avian Influenza. Today, we're going to be talking about another important animal disease, and that is African Swine Fever or ASF. And to join us for this discussion, we have one of our animal health experts here today with us. Her name is Lina Mur. A very warm welcome to you, Lina. How are you?
Very good, James. Very happy to be here with you.
Great. Well, we're happy to have you, too. Let's start, Lina. Maybe just tell us a bit about yourself, your background in dealing with African Swine Fever and then we go from there.
Perfect. So, I am a Spanish veterinarian and I started working with African Swine Fever when I was still a vet student. One of my professors said: “Ah, would you like to do some research?” I said: “Why not?” And he mentioned this disease and it sounds like “Africa… Cool, let's go there!”. At that time, nobody cared lot about the disease. So, I studied with a Ph.D. and travelled around the world seeing that it's a real problem. I got the opportunity to see Africa, Russia and different settings. And then, when I finished the Ph.D., I moved to the United States because I really wanted to try do research there because it is so different. It's totally different. And afterwards, I did some research there on vaccines, risk assessment. I came back in 2017 to Europe to work in the World Organization for Animal Health as an epidemiologist. So, I was analysing data and doing reports and so on. And in 2021, I joined EFSA. I am currently responsible for the African Swine Fever topics.
Great. Yeah. And you are a very important part of our team here for Animal Health. Maybe just to put a bit into context what we're talking about here, let's start at the beginning. What is African Swine Fever? It's got a name… obviously, you can guess that it comes maybe from a certain continent way back when, but maybe you just explain a bit of the history of the disease and what it is.
So, African Swine Fever is a viral disease that affects swine, wild and domestic pigs. So from the Phacochoerus, which is the African wild swine that you can see in the movies, to the wild boar and the pigs. But the good news is that it doesn't affect humans or other animal species, so it's a virus that affects pigs. It is called African Swine Fever because a long time ago there was another swine fever that was affecting the pigs. And the pigs were dying. But it was just in 1921, when they brought white pigs to Africa, to Kenya, when the pigs were starting to die. And they said: “What happened here?” And that's when they decided to call it African Swine Fever.
Okay. To distinguish it somehow from the classical swine fever. Okay, so it affects pigs. Importantly, it doesn't have an effect on human health. It's a serious disease, though, isn't it? And can have very, very grave consequences for pig populations. So just explain a little bit about I mean, the types of symptoms and what happens in the end if the disease is present.
Yeah, actually, it is a very nasty disease. Sometimes, it has been compared to the Ebola in animals because really, the rates of mortality of the pigs that got infected in the acute form, it can go to 97%. So, sometimes, you go to the farm and one day, they are okay and the next day, you have three pigs dead. So, you don't actually even see the fever, even if it was called fever. So, you can see sudden death, high fevers, the pigs are starting to feel bad, bleeding from the nose or with the faeces and from there, everything goes bad. Abortions and all sorts of distress that can cause the virus.
Okay. So very serious consequences ultimately leading to many cases of death. I guess, you know, from a kind of farming perspective or even if you, you know, just have smallholdings or whatever it may be, that can have a big impact on, you know, the animals that you keep because effectively it can wipe out the whole herd of animals.
Exactly. It has kind of two consequences. The first one is like if it gets there, you will lose your herd. But then it’s one of these diseases that are controlled by international organisations and in general, you know, you cannot let it spread like that. So, there are rules that say: “If you have the disease, I'm very sorry, but we will need to kill your pigs and destroy the product”. Meaning that you have been raising your pigs for, I don’t know, X months, whatever, and then you lose all of that. So, it's not only the direct effect of the virus killing the animals, but also the control policies: that you would need to kill the affected ones or the ones that have also been in contact. So, there's a lot of, yeah, a lot of losses there and the economic impact of the disease is huge. Definitely.
Yeah. And that's something that is that has affected the situation obviously in the European Union as well. I mean we read a lot about the economic impact of African Swine Fever on trade, on the farming industry. Maybe we use that just to bridge to EFSA’s role here. So, can you just explain a little bit more about the kind of work we're involved with there?
EFSA has played a crucial role, I think, since African Swine Fever got into the European Union in 2014 because there were so many things that we didn't know about the virus that the Commission needed to regulate, and they didn't know what to do. So, what EFSA has been doing since then is to help support the European Commission providing scientific and technical advice on this topic. During the past years, there were tons of reports and opinions saying: “Which is the role of the wild boar? What can we do to prevent it?” And so on. Now, currently, our job or how we are supporting the Commission is mainly by two different types of outcomes. We are producing annual reports where we evaluate how everything is going, if a country is doing better or worse, the situations we have a specific cluster of or a point where we need to pay attention. And then, we have every two years this risk factor analysis where we have a deeper insight in certain areas. So, we are now trying to select a region and say: “Okay, which is the role of the density of the wild boar in this region? How can we then take some conclusion that can help the European Commission to provide guidelines or legislate?” So that's what we are doing currently.
Okay. So, it's a kind of monitoring role in many senses. We're trying to keep track of what's happening, the epidemiology of the disease, the way it's evolving. So, we base that on data we are provided by the Member States, I presume.
Exactly. Part of our mandate is to collect information that the countries have on African Swine Fever. So, we are collecting from them the information from the laboratory directly. And it’s not only Member States, interestingly, also the neighbouring countries are providing us with data because they want to contribute and to provide that information to us. So, they support us with the laboratory data, with the peak population data and that's what helps us to evaluate how the disease is going and what we can recommend to the Commission, etc.
So, can you talk a little bit now, Lina, about how we are, where we are with ASF in the EU, because it's only relatively recently that we we've been talking about this or it's risen up the, you know, scientific political agenda.
It’s quite recent. Until 2007, yes, it was mostly located in African and on the island of Sardinia. That is an Italian island. But in 2007, it was discovered in Georgia, presumably brought by some products infected from Africa. And from there, gradually, it had continued spreading in neighbouring countries Armenia, Serbia, Russia, mostly through the wild boar. So, from 2007 until 2014, the disease was only in those non-European Union countries. But 2014 was when it first got detected in the Baltics. And from there, unfortunately, it has spread to Poland, the Eastern part of Germany, the Czech Republic. We also have Bulgaria, Hungary, Slovakia and the North of Greece infected. And I think one big point is that in 2018, the disease moved to other continents. So, it was when it entered into China. And from there, a lot of Asian countries have been affected. We have the Philippines, Vietnam, Korea, and they are dealing with similar problems with pigs and wild boars infected. No control. We don't have a vaccine right now. And finally, it was in 2021, when the disease got introduced into the Americas. It is in the Dominican Republic and Haiti and of course, that posed a huge risk for the neighbouring countries. So, we can say that nowadays, it is a worldwide problem and the whole veterinarian community is very aware of that. But if we talk about ten years ago, before it got into the European Union, nobody knew.
Different story. Yeah. So, you talk about the importance of awareness raising there, Lina, and maybe that allows us to bridge to the campaign that we're running at the moment, which you're obviously involved with as well. The campaign is called Stop ASF, so Stop African Swine Fever. It's something we launched four years ago now, and this is an information campaign aimed at specific target audiences, particularly vets, farmers, and hunters. And the aim there really is to raise awareness about the disease. And we talk in terms of three key areas. So, detect, prevent, and report. Do you want to tell us a little bit more about the campaign and what we're trying to achieve with that?
Definitely. So, I think it's a great campaign. To be honest, I was very happy when I joined EFSA, and I learned about what you were doing in terms of communication because I think you are really trying to change the behaviour of the people. So, you are sending clear messages, or we are sending a clear message: detect the disease. So, we have provided some pictures and some examples and say: “If you're a farmer and your pigs dying, or with this sort of lesions, this could be ASF”. That’s the first message. If you see a dead wild boar, that could be ASF. And for the veterinarians, we kind of refresh their minds because you are meant to study that at vet school. The second message is: report. So, what we want is to try make an early detection so the measures can be taken as soon as possible. The message there is, as soon as you see something that can be ASF, call your official vet or go to the hunters association, go to the official representatives that are meant to control the disease. And the third message is: try to help us prevent the spread of the disease. So, if you're a farmer, you always need to disinfect yourself, the boots, leave your clothes outside, do not visit other farms. If you bring out another animal, put it isolated. Try to always avoid wild boars around your farm, have a good fence. And a bit similar with the wild boars are hunters. If you have been hunting wild boars, please be aware and do not go into a pig farm afterwards. Do not move the falls. Do not move the products until the official vet has come and said their good to go.
Yeah, yeah. No, you’ve mentioned it's been a success. It really has. And I mean it is an EFSA campaign in some senses, but it relies very much on the contribution from partners in the Member States, but also in this case, given the specific distribution of the disease in Europe, we also work closely with pre-accession countries and many in fact over the period of the last four years. And it's an interesting model. It has a sort of centralised approach where we, you know, develop content and messages at the EFSA level and then work very much with our partners in the Member States, as I say, to distribute the information, reach out to stakeholders at the local level. So, yeah, if you're interested in finding out more about the Stop ASF campaign, you can find it quickly via any search engine if you just type in “Stop ASF” or from EFSA's website. So, if that's something of interest to you, do check it out. Okay, Lina. Maybe just looking forward a little bit. So, we've talked about what EFSA does, what the current situation is now. What are the next steps for, you know, public authorities, the European Commission, EFSA in dealing with this disease? I mean, presumably we're looking for, you know, a solution, if you like, a way of eradicating the disease altogether. And how close or far away are we from achieving that?
Yeah, I guess that we are in a similar situation of the first months of COVID when everybody was talking about vaccine, vaccine, vaccine, and we couldn't see it yet. So, in the case of ASF, a vaccine would be great. Of course, that's what a good vaccine and safe vaccine that can be used in the field for controlling the disease in wild boars is what we need. Unfortunately, we don't have one yet, but big improvements have been done in that area. We need to consider that African Swine Fever has been kind of a neglected disease, has been on the African continent and it came to Europe during the sixties, seventies and it was eradicated in old Europe except Sardinia, where it is still present. But it’s getting better. So, since 1995, until 2007, it was mostly an African disease. There was not much money invested, not much research put on it. While other diseases like Avian Influenza, foot and mouth disease, classical swine fever… there were big bodies pushing for that. So, they have good diagnostic tools and good vaccines. At EFSA, we are a bit late, and this is partially caused also by the complex structure of the virus. This is a huge virus. It is so big that in terms of size could be a bacterium but for the normal population that doesn't mean anything.
Do you mean that the virus, the physical size of the virus…?
The physical size of the virus is huge. And what it implies is that it has a lot of proteins. So, it's a very, very complex virus. We heard about the spike protein in COVID and the people became experts on “what protein”? African Swine Fever has more than hundred structural proteins. So, you can imagine that this is a super complex virus. So, to target that virus and to create the vaccine is very, very difficult because it's an expert at avoiding and escaping the immune system. So, I think there are two components. One, we have not invested enough money and research into it. And secondly, it's a very, very complex pathogen that we need to learn how to deal with.
But you say that there's hope for the future somehow. I mean, there is some scientific progress made on developing new ideas for vaccines or new protocols for vaccines. What’s in the pipeline?
So, we have several lines that are working pretty well and there are several approaches. We have attenuated vaccines, that means a virus that for naturally... that in the lab you make it less violent. So, you kind of kill the virus to make it less violent and put it into an animal and then when they put the real virus in, you are protected. And there are other groups working, for example, in removing, deleting specific genes that they know that are pathogenic. So, groups have been working on both lines for a long time, but now is when we are starting to see some positive results. So, there are even some countries in Asia, at the moment it's only Vietnam, but they have authorised the use of some vaccines produced by the USA in the national labs. They are doing the field work. So, we need to wait a bit in terms of how things are going. All the work in wild boar in Europe is quite promising. So, we are in kind of an exciting moment where from now to the following years, I think we'll see -or I hope that we will see- big breaks in the vaccine research.
Okay, let's, uh. Well, let's hope that becomes a reality. In the meantime, here at EFSA, obviously, we continue important work on the monitoring and the risk assessment. And with that, Lina, I think that probably brings us to an end of this conversation. Thank you very much for being with us here today.
Thanks to you, James. It has been a real pleasure.
To all our listeners, if you're interested in finding out more about this topic, please do check out our website. I mentioned the campaign already, the communications campaign we're running. It's called “Stop ASF”. You can find that too, just by going to our website. And otherwise, we look forward to seeing you on the next episode of Science on the Menu. Thank you very much and goodbye.
Host: James Ramsay, Head of COM Unit.
Guest: Lina Mur, Scientific Officer at AHAW.
James Ramsay and Lina Mur.
Disclaimer: Views expressed by interviewees do not necessarily represent the official position of the European Food Safety Authority. All content is up to date at the time of publication.