Tag: cancer vaccine

Turning Everyday Vaccines into Cancer Killers

Photo by National Cancer Institute

A study in Frontiers in Immunology has demonstrated that, in animal models, a protein antigen from a childhood vaccine can be delivered into the cells of a malignant tumour to refocus the body’s immune system against the cancer, effectively halting it and preventing its recurrence.

Instead of using vaccines tailored with tumour-specific antigens to prime the immune system to attack a particular cancer, this method makes use of the immune system’s encounter with common vaccines. The bacteria-based intracellular delivering (ID) system uses a non-toxic form of Salmonella that releases a drug, in this case a vaccine antigen, after it’s inside a solid-tumour cancer cell.

“As an off-the-shelf immunotherapy, this bacterial system has the potential to be effective in a broad range of cancer patients,” writes senior author Neil Forbes, professor of chemical engineering, in the recently published article.

The research, carried out in Forbes’s lab, offers promise toward tackling difficult-to-treat cancers, including liver, metastatic breast and pancreatic tumours.

“The idea is that everybody is vaccinated with a whole bunch of things, and if you could take that immunisation and target it towards a cancer, you could use it to eliminate the cancer,” Forbes explains. “But cancers obviously aren’t going to display viral molecules on their surface. So the question was, could we take a molecule inside the cancer cell using Salmonella and then have the immune system attack that cancer cell as if it was an invading virus?”

To test their theory that this immune treatment could work, Forbes and team genetically engineered ID Salmonella to deliver ovalbumin (chicken egg protein) into the pancreatic tumour cells of mice that had been immunised with the ovalbumin ‘vaccine’. The researchers showed that the ovalbumin disperses throughout the cytoplasm of cells in both culture and tumours.

The ovalbumin then triggered an antigen-specific T-cell response in the cytoplasm that attacked the cancer cells. The therapy cleared 43% of established pancreatic tumours, increased survival and prevented tumour re-implantation, the paper states.

“We had complete cure in three out of seven of the pancreatic mice models,” Forbes says. “We’re really excited about that; it dramatically extended survival.”

The team then attempted to re-introduce pancreatic tumours in the immunised mice. The results were exceedingly positive. “None of the tumours grew, meaning that the mice had developed an immunity, not just to the ovalbumin but to the cancer itself,” Forbes says. “The immune system has learned that the tumour is an immunogenic. I’m doing further work to figure out how that’s actually happening.”

In preliminary research, the team previously showed that injecting the modified Salmonella into the bloodstream effectively treated liver tumours in mice. They advanced their findings with the current research on pancreatic tumours.

Before clinical trials can begin, the researchers will repeat the experiments on other animals and refine the ID Salmonella strain to ensure its safety for use in humans. Liver cancer would be the first target, followed by pancreatic cancer.

Source: University of Massachusetts Amherst

SA Healthcare Bolstered With Vaccine Lab Investment and Loans

Photo by Louise Reed on Unsplash

Last week, South African healthcare received a double shot in the arm with the opening of a local vaccine manufacturing facility and the approval of a World Bank loan to bolster social safety nets and health systems.

On Wednesday, President Cyril Ramaphosa and health technology billionaire Dr Patrick Soon-Shiong officially opened a new vaccine manufacturing facility in Brackenfell, Western Cape.

The South African-born entrepreneur has been strongly supporting local healthcare, with R3 billion invested to help SA share vaccine technology with the rest of Africa. His company, ImmunityBio, is developing a T-cell based universal COVID vaccine, currently in Phase III trials in SA. The same adenovirus vector technology it uses is also being tested in cancer vaccines.

“It has been a dream of mine, since I left the country as a young physician, to bring state-of-the-art, 21st century medical care to SA and to enable the country to serve as a scientific hub for the continent,” Dr Shoon-Siong had previously said. The technology transfer will help “establish much-needed capacity and self-sufficiency.”

The hub will transfer technology, know-how and materials for DNA, RNA, adjuvant vaccine platforms and cell therapies to SA.

“There is no reason we couldn’t make 500 million doses a year,” said Dr Soon-Shiong, who is also a Wits alumnus. “Subject to the raw material being available.”

He said he wants to tap the country’s expertise on prevalent diseases such as HIV and cervical cancer. “There are fantastic scientists with deep knowledge about these diseases,” he said. “More so than in America because they see these patients every day.”

President Ramaphosa and Dr Soon-Shiong also launched the Coalition to Accelerate Africa’s Access to Advanced Healthcare, which aims to drive the development of innovative therapeutics and ensure the continent is prepared for future pandemics.

The coalition aims to manufacture a billion doses of the COVID vaccine by 2025 and to develop treatments for conditions including cancer, COVID, tuberculosis and HIV.

South Africa also received approval from the World Bank for a US$750 million COVID relief loan aimed at reducing the worst of the pandemic’s impact on the poor.

“The World Bank budget support is coming at a critical time for us and will contribute towards addressing the financing gap stemming from additional spending in response to the COVID crisis,” said Dondo Mogajane, Director General of the National Treasury. “It will assist in addressing the immediate challenge of financing critical health and social safety net programs whilst also continuing to develop our economic reform agenda to build back better.”

Meanwhile, Health Minister Dr Joe Phaahla warned that South Africa will likely enter a fifth wave when cold temperatures in May, though what COVID variants may drive it remain to be seen.