The full story
This is the episode's narration, word for word. Headings jump to that point in the video.
The question 0:00
You can't catch cancer. Or so most of us assume. But almost every case of cervical cancer starts with a virus you catch, and can vaccinate against. In 1991, two scientists in Brisbane and their small team made the first version of the thing that vaccine is built on: the empty shell of a virus, with nothing inside. How can an empty shell protect you from cancer? And why does one of those two scientists so often get left out?
A very common virus 0:32
The virus is the human papillomavirus, or HPV. It's a loop of DNA wrapped in a protein shell, about fifty-five millionths of a millimetre across. There are more than two hundred types, mostly harmless. About a dozen are high-risk, above all types 16 and 18. Nearly everyone who is sexually active catches HPV at some point, usually without noticing. And usually, the immune system clears it within a year or two.
How a wart virus causes cancer 1:08
So how does a wart virus cause cancer? HPV infects the bottom layer of skin-like tissue, and to copy itself, it needs that cell to keep copying its DNA. So it makes two proteins, E6 and E7, that destroy two of the cell's brakes, called p53 and Rb. If a high-risk type hangs on for years, damaged cells can turn precancerous, then cancerous. That usually takes fifteen to twenty years.
How we know 1:42
In the 1970s, an early suspect for cervical cancer was a herpes virus. The German virologist Harald zur Hausen bet on papillomavirus instead. His logic: if a virus caused the tumour, its DNA should still be inside the tumour cells, so go and look. In 1983 he found a new type, HPV 16, in cervical cancers, and in 1984, HPV 18. Together they turn up in about seventy per cent of cervical cancers worldwide. In 2008, he shared the Nobel Prize in Physiology or Medicine for it.
How a vaccine teaches 2:25
Your immune system learns the shapes on the outside of a germ, called antigens, and makes antibodies that fit them. The first time is slow, but it leaves memory cells behind, so the next response is faster and stronger. A vaccine stages that first meeting safely, with a killed, weakened or partial version of the germ.
Why HPV was a problem 2:49
For HPV, none of the usual routes worked. You can't kill or weaken a virus you can't grow, and HPV only completes its life cycle in maturing skin cells, not in ordinary lab cultures. Every HPV also carries those cancer genes, so a vaccine couldn't contain its DNA. And its shell protein, made in bacteria, came out in the wrong shape, probably unfolded, and the antibodies it raised didn't block the real virus.
The idea: an empty shell 3:21
So the goal was a decoy. A shell folded exactly like the real virus, with nothing inside. The immune system learns the outside, so it would learn the right shape. With no genes inside, there's nothing to infect you, and nothing to cause cancer. It's called a virus-like particle.
Two strangers in Cambridge 3:42
In 1989, Ian Frazer, a Scottish-born immunologist working in Brisbane, was visiting a lab in Cambridge. Next door he met Jian Zhou, a virologist from China who also worked on HPV. Both needed the same impossible thing: the virus itself, to study. In 1990, Zhou and his wife, Xiao-Yi Sun, also medically trained, joined Frazer's laboratory at the University of Queensland.
A year of failure 4:16
Their plan was to get cells to build the shell for them. They put the genes for the two shell proteins, L1 and L2, into a virus that carries genes into monkey cells. For about a year, it didn't work. In Frazer's words, they were "nearly at the point of giving up". Then, early in 1991, the electron microscopist Deborah Stenzel found them: tiny shells, forty millionths of a millimetre across. That year, Zhou, Sun, Stenzel and Frazer wrote that they "could provide a safe source of material for the development of a vaccine".
Why the shell works 4:57
The shell is 72 five-sided units, each made of five copies of a protein called L1, so 360 in all. Made inside the right kind of cell, L1 folds properly and the pieces assemble on their own. And how do we know antibodies are enough? In dogs, shells of a dog papillomavirus protected against live virus. Serum from vaccinated dogs passed that protection on, and unfolded shells didn't protect.
The race 5:32
Brisbane wasn't alone. In 1992, at the US National Cancer Institute, Reinhard Kirnbauer, Douglas Lowy and John Schiller showed that L1 alone builds the shell, and makes strong antibodies that block the virus. Teams in Rochester and Seattle made shells too, and a Georgetown team tested them in dogs. The Cancer Institute's own account says the Brisbane team found L1 alone made no shells, and calls their 1991 particles "aberrant". Frazer replies that his gene was the correct natural version, while the standard copy others first used had a mutation. Both sides have a stake.
Who was first? 6:19
Then came the patents. Queensland, the Cancer Institute, Georgetown and Rochester all claimed the original work. Frazer and Zhou had filed in Australia on the nineteenth of July 1991. In the US, the deciding case was Queensland against Georgetown. In 2005, a patent board gave priority to Georgetown, because back then Frazer had thought both proteins were needed. In 2007, an appeals court reversed that, and awarded priority to Frazer and Zhou. The US patent, granted in 2009, names them both as inventors. By then, Jian Zhou had been dead for almost ten years.
Jian Zhou 7:05
In early 1999, Zhou fell ill. He travelled to China, became critically ill within days, and died there in March, aged forty-two. Years later, his wife said she still didn't really know what had happened. Frazer has always acknowledged him as co-inventor, and has called him "an equal partner". He has shared his royalties with Zhou's widow and son. In 2008, a commemorative service for Zhou was held at Queensland's Parliament House. Frazer said Zhou lived long enough to see that their work "would probably lead to a vaccine for cervical cancer".
From particle to product 7:46
Turning that into a vaccine took about fifteen years and two drug companies. Merck grew the shells in yeast, GlaxoSmithKline in insect cells. On the eighth of June 2006, the US regulator approved Merck's Gardasil, the first vaccine to prevent cervical cancer caused by the HPV types it covers. Australia registered it the same month. GSK's Cervarix followed. One limit matters: they prevent infection, but don't clear one you already have.
Australia goes early 8:24
In April 2007, Australia began free HPV vaccination for girls aged twelve and thirteen, through schools, with a catch-up for young women up to twenty-six until 2009. It was one of the first national programmes in the world. Boys were added in 2013, and a vaccine covering nine types replaced the original in 2018. This is history, not advice: questions about vaccination are for a doctor.
The evidence comes in 8:58
Warts showed early. At sexual health clinics, the Kirby Institute found the share of women under twenty-one with genital warts fell from eleven and a half per cent in 2007 to under one per cent in 2011. It fell sharply in young heterosexual men too, before boys were vaccinated, which the researchers said was probably herd immunity. In women aged eighteen to twenty-four, the vaccine-targeted HPV types fell from twenty-nine per cent to seven.
But does it stop cancer? 9:30
Fewer infections should mean fewer cancers, but that takes decades to see. The clearest direct evidence comes from Sweden: among one point seven million girls and women, those vaccinated before seventeen had about eighty-eight per cent less cervical cancer. In Australia, the rate has more than halved since 1982, to about seven cases per hundred thousand women in 2021. But most of that came from screening. The schoolgirls vaccinated in 2007 are only in their early thirties, and this cancer peaks in women in their late thirties. Women in the catch-up were mostly vaccinated older, when many already had HPV.
The projection 10:15
Below four cases per hundred thousand women counts as eliminating cervical cancer as a public health problem. On the World Health Organization's age adjustment, which that target uses, Australia's 2021 rate was six point two, not about seven. A 2018 Cancer Council modelling study, with Frazer as a co-author, projected Australia could get there around 2028, somewhere between 2021 and 2035. The government's target is 2035. These are projections, not results, and they assume vaccination and screening stay high. Vaccination of girls slipped after the pandemic, from about eighty-seven per cent in 2020 to eighty-one in 2024.
Who gets the credit? 11:04
So who invented the cervical cancer vaccine? No single person. Harald zur Hausen found the cause. Frazer and Zhou, with Xiao-Yi Sun, made the first papillomavirus-like particles to be reported, and won the key US patent case. The Cancer Institute team showed that L1 alone was enough, and made strong antibodies. Merck and GSK turned it into medicine. In 2006, Frazer was named Australian of the Year. But the patent carries two names.
Next: skin 11:44
That year, Reader's Digest readers ranked Frazer the second most trusted person in Australia. The only one ahead of him was the burns surgeon Fiona Wood, Australian of the Year the year before. Her work is next. How do you grow new skin for someone who has lost most of theirs, and why would you spray it on?
Sources
Every factual claim in the episode is tied to one of these. Spotted an error? Tell us.
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Image credits
- Colorised electron micrograph of HPV particles · NIAID · CC BY 2.0 · via Wikimedia Commons · licence: https://creativecommons.org/licenses/by/2.0/
- Harald zur Hausen, Heidelberg, 2010 · photo Armin Kübelbeck · CC BY-SA 3.0 · via Wikimedia Commons · licence: https://creativecommons.org/licenses/by-sa/3.0/
- Ian Frazer, Canberra, 2008 · photo Graeme Bartlett · CC BY-SA 3.0 · via Wikimedia Commons · licence: https://creativecommons.org/licenses/by-sa/3.0/
Researched and scripted with AI assistance, fact-checked claim by claim, with synthetic narration and diagrams drawn in code. How we make episodes.
