Examination Room: Andrew Waller

Andrew Waller has devoted many years to the study of Streptococcus equi and he’s at the forefront of work behind an exciting new vaccine for strangles. The former head of bacteriology at the AHT and current chief scientific officer at Intervacc stepped into the Examination Room to tell us more…
Q
How long have you worked for Intervacc and what is your background?

AI’ve worked at Intervacc for almost two years now, although I’ve been collaborating with the team in Sweden for almost 19 years. I’ve always had a massive interest in the mechanisms that underpin disease, and I’m passionate about using science to improve the health of humans and animals.

I completed a PhD, rather a long time ago now, examining some of the molecular mechanisms that influence the development and treatment of prostate cancer, which affects around one in eight men. I thoroughly enjoyed learning more about how therapeutic drugs could be used to kill cancer cells and help affected patients, so I moved into the pharmaceutical industry, where I applied the techniques I’d learned to develop new drugs against inflammatory disease, HIV, obesity and antibiotic-resistant infections.

It was this latter area that really caught my interest, and I wanted to do more to reduce the impact of antibiotic resistance by helping to stop people and animals from becoming infected by dangerous bacteria in the first place. So, I joined a research charity, the AHT, as head of bacteriology in 2003, to learn more about how bacteria cause disease in animals and how we might prevent the spread of infection from one animal to another.

Throughout my work studying infectious disease of animals, I’ve been extremely fortunate to work and collaborate with an army of incredibly dedicated people from across the world, and to apply the very latest techniques to analyse bacteria and learn more about how they interact with the animals they infect.

I’ve particularly enjoyed working on Streptococcus equi, which is the cause of strangles in horses. The name strangles was coined because the infection can lead to the formation of abscesses in the lymph nodes of the horse’s neck that are so large they restrict the airway. Despite the often horrific clinical signs of strangles, the mechanisms used by S equi to cause disease are incredibly interesting.

For example, we identified an iron-acquisition system that is shared with Yersinia pestis, the bacteria that causes bubonic plague (Black Death), a disease of the buboes (lymph nodes) in humans. We showed that this system was essential for S equi to cause strangles in horses. Then we developed a diagnostic PCR test that targeted this region of S equi’s DNA, which we transferred to laboratories throughout the world to help identify infected horses so they can be isolated before they pass on the infection to others. We also studied the immune responses of horses as they fought off S equi. We used this information to develop a blood test that identifies horses that have been exposed to S equi and new vaccines to prepare the horse’s immune response. The blood test has similarly been transferred to laboratories throughout the world and its use as a pre-import screen has been attributed to the absence of strangles outbreaks in the United Arab Emirates over the past four years.

Our vaccine work has been even more exciting, and has huge potential to reduce the suffering of horses throughout the world by preventing infection when they are transported or attend competitions and sales.

Q

What does your role at Intervacc entail?

A

I’m chief scientific officer at Intervacc, so I work with scientists and veterinarians throughout the world to learn more about how bacteria cause disease in animals, and how we can develop new vaccines that break the chain of infection.

We decipher some of the key mechanisms that are used by bacteria to cause disease. Then, we use fragments of the bacterial proteins involved to generate immune responses that block the function of these proteins, and efficiently target and kill the invading bacteria.

I’m not only working to prevent strangles in horses: our vaccines against Streptococcus suis, which causes sepsis, meningitis and arthritis in pigs, and Staphylococcus aureus – a major cause of mastitis in dairy cows – are also making good progress. It has been fascinating to learn more about the diseases that these, and other bacteria, cause, and to design new studies to measure the protection provided by our new vaccines.

Q

It’s an exciting time for you – why’s that?

A

Bacterial pathogens are really complex and the development of effective vaccines has provided a monumental challenge for scientists around the world. However, the ability to fuse fragments of important proteins from these bacteria together, and use them in vaccines that generate a broad immune response, has massive potential to improve animal health.

Strangvac, our vaccine against strangles in horses, uses eight different proteins from S equi, which are fused together to make three proteins in the final vaccine. This makes the proteins easier to produce, while generating a broad-acting immune response. In one of our studies where we trialled Strangvac, which was published in the scientific journal Vaccine in 2020, we showed that three doses of vaccine protected 94 per cent of ponies from a dose of S equi that caused disease in all of the control ponies. I’ve studied S equi for 19 years and we’d thought that this level of protection would be impossible to achieve, so it was incredible to see the difference the vaccine made. I’m thrilled that Strangvac is now approved and ready to be used in horses throughout Europe.

It’s also extremely exciting that this approach, to fuse several important bacterial proteins together within vaccines, may also soon benefit the health of pigs, cows and other animals, too.

Q

Tell us about a typical working day?

A

I am so lucky to work with so many amazing people throughout the world. Each day, I am able to discuss outbreaks of disease with veterinarians to learn more about the challenges they face.

I review new scientific advances and discuss these with our brilliant teams at the Swedish University of Agricultural Sciences in Uppsala, and the Karolinska Institute in Stockholm. I design new studies and work with our collaborators to get the maximum amount of information from these, while ensuring the welfare of animals remains our top priority. I then analyse new data as it comes in, so we can design the next wave of studies, or I write up our results for publication in scientific journals and patents.

I’m also very lucky to work with our talented development, regulatory and sales teams, which produce our new vaccines and optimise how they can be used in the real world to prevent disease.

Q

What do you enjoy most about your job?

Maybe this is a bit geeky, but the absolute best feeling comes from analysing new data, seeing that a vaccine has had a protective effect and then communicating this to everyone.

I am incredibly privileged to be able to see the whole process, from identifying a clinical problem through to launching a new vaccine, and it is fantastic that the work that we are doing could improve the health of animals right across the world.

Q

What advice would you give to people interested in a career in research and development?

A

Go for it. There’s never been a better time to have a career in research and development. The new technologies are game changers and enable the identification of important targets in weeks, which would previously have required many years. The benefits of these approaches to society have never been more clear. For example, the use of vaccines against COVID-19 was estimated to have saved more than half a million lives in Europe by the end of last year.

There are so many other diseases for which vaccines are needed urgently, not least to ensure the security of food production and combat the development of antibiotic resistance.

It is incredible that scientific studies conducted in Sweden and at the AHT in the UK will help to improve the health of horses across the world, and I think this is a brilliant example of the type of far-reaching impact that a career in research and development can have.

Q

If you could give your younger self a piece of advice, what would it be?

A

Try not to work pasture bedtime!