Adrian Hill, PhD, is co-founder of Oxford University of spin-off Vaccitech, director of the Jenner Institute at Oxford University, and co-author on a recent preclinical study into two-dose cancer vaccines. Vaccitech is using the viral vector technology behind the Oxford AstraZeneca COVID-19 vaccine. Here, he talks to GEN about manufacturing challenges and the triumph of vaccine hype.

GEN: You’re currently in a Phase II trial of a prostate cancer vaccine. What do you see as the major manufacturing challenges of this new class of therapeutics?

You could argue that bioprocessing is the least of our problems in making cancer vaccines because we can manufacture them already. There’s nothing different about how we manufacture viral vectors for cancer compared to how we do it for COVID-19—except that you don’t need as many doses.

We’re producing billions of doses of the ChAdOx1 vector for COVID-19 this year, and the challenge is different. You need to produce vast amounts and inexpensively, so you can use it in the poorest countries in the world. Whereas, for cancer, you’re going to be doing maybe tens of thousands of patients each year post licensure, so, you don’t need so much product, and you can charge, at least $1,000 a dose.

Adrian Hill, PhD

GEN: We’ve spoken recently to people who’ve talked about personalized mRNA vaccines for cancer. Do you see these as likely to go into production soon?

I thought that the hype about personalized cancer vaccines died down a bit, but clearly not. There are two big problems. One is that we have no proof-of-concept of it working, despite huge investment by all sorts of groups, including BioNTech. And, even if they did work, the business case would be difficult—you’d have to make a vaccine in weeks, which we can do, but the cost of making an individual vaccine for an individual patient is going to be many tens of thousands of dollars, if not more.

GEN: When do you expect viral vector cancer vaccines to reach the market?

In the best-case scenario, in the next three to five years. One problem is the cost of checkpoint inhibitors, to the extent that academics, like me, are impeded from doing cancer vaccine trials. That’s slowing down progress because you need checkpoint inhibitors for most vaccines to work in cancer—because of immunosuppressive tumors. So, if I could have one wish in cancer manufacturing, it would be making $10 to $100 per dose checkpoint inhibitors.