vaccine to protect against hepatitis C

 A vaccine to protect against hepatitis C virus (HCV) could be in use within five years, according to University of Alberta Nobel laureate Michael Houghton, who made the announcement during a special presentation at this year’s European Congress of Clinical Microbiology and Infectious Diseases held in Vienna, Austria, over the weekend.

Michael Houghton, who won the Nobel Prize in Physiology or Medicine last year for his co-discovery of the hepatitis C virus, says a vaccine could be in use within five years if clinical trials prove it is safe and effective. (Photo: Michael Holly)

“While the advent of directly acting antivirals to cure HCV has given us a huge weapon to turn the tide on this pandemic, there is no doubt that a vaccine is required to help the world reach its ambitious target of reducing new HCV infections by 90 per cent and mortality rates by 65 per cent by 2030,” said Houghton, a virologist in the Faculty of Medicine & Dentistry and director of the Li Ka Shing Applied Virology Institute .

Up to two million new HCV infections occur every year around the world, with an estimated 70 million carriers of the virus globally, most of whom are not diagnosed. The virus is estimated to cause some 400,000 deaths annually. Many infected with the virus go on to develop liver cirrhosis and liver cancer.

Houghton said while countries like Egypt have managed to enact huge control programs for HCV—50 million screened and four million treated and cured using antivirals since 2014—they have only been able to do so thanks to mass production of generic drugs at $105 per patient. The cost per patient in high-income countries is closer to $25,000 per patient.

He explained the scientific community has learned that both neutralizing antibodies and cellular immune responses correlate with HCV immunity, and both the new RNA technology—used in the Pfizer and Moderna COVID-19 vaccines—and adenovirus-based technologies of the sort developed by Oxford University and AstraZeneca, and Johnson & Johnson—are able to reproduce these protective immune responses through vaccination.

Houghton and colleagues at the Li Ka Shing Applied Virology Institute are now developing an adjuvanted recombinant vaccine, which is expected to induce production of many kinds of antibodies that can prevent HCV infection, making it very hard for the virus to evade them by mutation and thus protecting the vaccine recipient from HCV infection.

Although the COVID-19 pandemic has pushed back many areas of medical research, including work on HCV vaccines, Houghton anticipates Phase 1 clinical trials in 2022 using different adjuvants followed by Phase 2 human efficacy trials from 2023 to 2026, either in an at-risk population such as people who inject drugs, or through human vaccine challenge trials.

“If safety and efficacy are proven, rollout of the vaccine to the high-risk population could begin in 2026-27,” Houghton noted. “Following Phase 3 trials, the HCV vaccine could then be rolled out to other high-risk groups in or around 2029, such as men who have sex with men, health-care workers, and babies born to mothers with HCV, in all countries of the world.”

The savings could be immense. In Canada, for instance, Houghton said it is estimated that treating people who inject drugs with directly acting antivirals over a decade would incur drug costs of around $1 billion, compared with $20 million estimated for vaccine costs to protect the same population.

Houghton was awarded the 2020 Nobel Prize in Physiology or Medicine along with Harvey J. Alter and Charles M. Rice for the discovery of HCV in 1989.

The European Congress of Clinical Microbiology and Infectious Diseases has become one of the most comprehensive and influential congresses in the field of infection that brings together more than 13,000 colleagues from all over the world.